Michael Chaly and Disservin
9cc15b3049
Do more reductions for cut nodes without a tt move
...
Logic is somewhat similar to IIR but in LMR.
Usually things like reducing more in IIR scale badly but this patch does
this in LMR where reducing more for cutNodes is in general good, so I
believe there is no non-linear scaling.
Passed STC:
https://tests.stockfishchess.org/tests/view/67abc9aaa04df5eb8dbeb452
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 42304 W: 11223 L: 10892 D: 20189
Ptnml(0-2): 184, 4904, 10669, 5187, 208
Passed LTC:
https://tests.stockfishchess.org/tests/view/67abcd7ba04df5eb8dbeb96c
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 32334 W: 8386 L: 8074 D: 15874
Ptnml(0-2): 26, 3446, 8916, 3748, 31
closes https://github.com/official-stockfish/Stockfish/pull/5875
Bench: 2612849
2025-02-13 19:49:54 +01:00
Michael Chaly and Disservin
e852d9880a
Reduce less for positions without tt move
...
Continuation of work on scaling.
In line with previous scaling patches this one massively reduces
reduction for moves that don't go thru lmr for position without a tt
move.
Passed VVLTC with STC bounds:
https://tests.stockfishchess.org/tests/view/679fd2450774dfd78deb12b2
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 74718 W: 19354 L: 19042 D: 36322
Ptnml(0-2): 5, 6724, 23595, 7024, 11
Passed VVLTC with LTC bounds:
https://tests.stockfishchess.org/tests/view/67a009930774dfd78deb2346
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 82638 W: 21587 L: 21212 D: 39839
Ptnml(0-2): 15, 7476, 25953, 7869, 6
closes https://github.com/official-stockfish/Stockfish/pull/5860
Bench: 2887850
2025-02-04 21:37:11 +01:00
Michael Chaly and Disservin
3b8bfeb38a
Do less aggressive pruning for higher movecounts
...
Move part of heuristic that makes reduction less before pruning stage.
Passed STC:
https://tests.stockfishchess.org/tests/view/679fdf1b0774dfd78deb13b3
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 47136 W: 12484 L: 12146 D: 22506
Ptnml(0-2): 211, 5472, 11866, 5806, 213
Passed LTC:
https://tests.stockfishchess.org/tests/view/679fe6790774dfd78deb1753
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 100536 W: 25837 L: 25383 D: 49316
Ptnml(0-2): 103, 10990, 27622, 11456, 97
closes https://github.com/official-stockfish/Stockfish/pull/5853
Bench: 3265587
2025-02-04 21:28:49 +01:00
Michael Chaly and Disservin
dabffbceff
Make pruning at ttpv nodes more aggressive
...
Continuation of work done by @FauziAkram and @Viren6 They had a series
of patches that decrease pruning for ttPv nodes - and it passed as a
gainer at lower time controls while revert passed as a gainer at higher
time controls.
So it's a logical continuation of this work that increases pruning for
ttPv nodes in hopes of scaling to longer TCs.
Fixed games STC:
https://tests.stockfishchess.org/tests/view/679ee3910774dfd78deb0efd
Elo: -4.98 ± 2.1 (95%) LOS: 0.0%
Total: 28584 W: 7229 L: 7639 D: 13716
Ptnml(0-2): 143, 3579, 7219, 3247, 104
nElo: -9.54 ± 4.0 (95%) PairsRatio: 0.90
Passed VVLTC with STC bounds:
https://tests.stockfishchess.org/tests/view/679d21f70774dfd78deaf553
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 323282 W: 83729 L: 83105 D: 156448
Ptnml(0-2): 37, 29842, 101269, 30446, 47
Passed VVLTC with LTC bounds:
https://tests.stockfishchess.org/tests/view/679e7a970774dfd78deb0cd3
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 113712 W: 29485 L: 29051 D: 55176
Ptnml(0-2): 13, 10376, 35640, 10818, 9
closes https://github.com/official-stockfish/Stockfish/pull/5844
Bench: 2964045
2025-02-02 13:47:52 +01:00
Michael Chaly and Disservin
40e0486d02
Make IIR for PvNodes less aggressive
...
In line with previous experiments on improving scaling of IIR.
Now it disables IIR for pv nodes with depth <= 2, so disallowing for it
to perform a qsearch dive.
Fixed games STC:
https://tests.stockfishchess.org/tests/view/679ae6a951037ccaf3e30fb3
Elo: -10.36 ± 2.5 (95%) LOS: 0.0%
Total: 20020 W: 4902 L: 5499 D: 9619
Ptnml(0-2): 128, 2653, 4976, 2194, 59
Passed VVLTC with STC bounds:
https://tests.stockfishchess.org/tests/view/67954f2e406a4efe9eb7d266
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 196758 W: 50725 L: 50258 D: 95775
Ptnml(0-2): 21, 18153, 61564, 18620, 21
Passed VVLTC with LTC bounds:
https://tests.stockfishchess.org/tests/view/6795a26bf6281b7d7b18698b
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 323092 W: 83679 L: 82857 D: 156556
Ptnml(0-2): 48, 29475, 101659, 30335, 29
closes https://github.com/official-stockfish/Stockfish/pull/5834
Bench: 3464332
2025-02-02 13:37:47 +01:00
Michael Chaly and Joost VandeVondele
7701d0b3c4
Introduce one more continuation history
...
This one is counter counter counter history - with really low update value and divided by 3 in movepicker unlike the other ones.
Passed STC:
https://tests.stockfishchess.org/tests/view/67861495460e2910c51de720
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 44352 W: 11699 L: 11370 D: 21283
Ptnml(0-2): 156, 5098, 11361, 5383, 178
Passed LTC:
https://tests.stockfishchess.org/tests/view/6786e89e3b8f206a2696b646
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 432660 W: 110355 L: 109207 D: 213098
Ptnml(0-2): 381, 48214, 118039, 49268, 428
closes https://github.com/official-stockfish/Stockfish/pull/5792
Bench: 1491837
2025-01-18 21:04:55 +01:00
Michael Chaly and Disservin
8b32e4825f
Make IIR less aggressive
...
This patch is an elo gaining simplification which gains elo at longer time controls.
Patch disallows IIR for cutNodes with existing tt moves as well as makes
IIR for pv nodes less aggressive, basiclally confirming suspected
scaling patterns for this heuristic.
Result of 50k games STC run:
https://tests.stockfishchess.org/tests/view/678304676ddf09c0b4b6f9f9
Elo: -2.93 ± 1.6 (95%) LOS: 0.0%
Total: 50000 W: 12718 L: 13140 D: 24142
Ptnml(0-2): 189, 6087, 12835, 5735, 154
nElo: -5.71 ± 3.0 (95%) PairsRatio: 0.94
Passed VVLTC SPRT with STC bounds:
https://tests.stockfishchess.org/tests/view/6782eb1a6ddf09c0b4b6e6b0
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 150292 W: 38868 L: 38458 D: 72966
Ptnml(0-2): 19, 13890, 46907, 14322, 8
Passed VVLTC SPRT with LTC bounds:
https://tests.stockfishchess.org/tests/view/6782d8d96ddf09c0b4b6df18
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 153388 W: 39791 L: 39285 D: 74312
Ptnml(0-2): 13, 13924, 48311, 14436, 10
closes https://github.com/official-stockfish/Stockfish/pull/5763
Bench: 1507606
2025-01-12 21:25:36 +01:00
Michael Chaly and Disservin
03e4cde729
Allow Pv nodes at certain conditions to spawn zero window searches deeper than default
...
In current case it's allowed if there is no best move.
Passed STC:
https://tests.stockfishchess.org/tests/view/67640fd586d5ee47d9543d5a
LLR: 2.96 (-2.94,2.94) <0.00,2.00>
Total: 392480 W: 102038 L: 101192 D: 189250
Ptnml(0-2): 1303, 46287, 100253, 47055, 1342
Passed LTC:
https://tests.stockfishchess.org/tests/view/67671a4686d5ee47d9544476
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 128616 W: 32941 L: 32433 D: 63242
Ptnml(0-2): 84, 13997, 35634, 14513, 80
closes https://github.com/official-stockfish/Stockfish/pull/5733
Bench: 1095871
2025-01-06 00:40:05 +01:00
Michael Chaly and Disservin
79261bec59
Simplify away reductions adjustment for multithreaded search
...
Seem to no longer bring measurable benefit.
Passed STC SMP simplification:
https://tests.stockfishchess.org/tests/view/6753561a86d5ee47d954151f
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 38000 W: 9864 L: 9656 D: 18480
Ptnml(0-2): 53, 4177, 10320, 4409, 41
Passed LTC SMP simplification:
https://tests.stockfishchess.org/tests/view/6753d75f86d5ee47d9541669
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 258674 W: 66314 L: 66335 D: 126025
Ptnml(0-2): 77, 26957, 75303, 26910, 90
Passed 16 threads LTC simplification:
https://tests.stockfishchess.org/tests/view/675a066286d5ee47d9542296
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 221804 W: 56950 L: 56936 D: 107918
Ptnml(0-2): 34, 21491, 67839, 21503, 35
closes https://github.com/official-stockfish/Stockfish/pull/5729
Bench: 1294909
2024-12-22 15:28:15 +01:00
Michael Chaly and Disservin
afaf3a0f2a
Refine statscore for captures
...
Continuation of previous attempts there.
Now instead of using capture history with a static offset also add the
value of the captured piece in the same way at it is used in movepicker.
Passed STC:
https://tests.stockfishchess.org/tests/view/674aa3d386d5ee47d95404aa
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 116480 W: 30433 L: 29999 D: 56048
Ptnml(0-2): 361, 13720, 29662, 14118, 379
Passed LTC:
https://tests.stockfishchess.org/tests/view/674c4b2d86d5ee47d954073f
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 133542 W: 34365 L: 33847 D: 65330
Ptnml(0-2): 78, 14585, 36934, 15089, 85
closes https://github.com/official-stockfish/Stockfish/pull/5706
Bench: 934447
2024-12-08 19:57:59 +01:00
Michael Chaly and Disservin
cd3c13a883
Further tweak statscore for captures
...
Even lower offset.
Passed STC:
https://tests.stockfishchess.org/tests/view/673a66d786d5ee47d953f070
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 63776 W: 16570 L: 16216 D: 30990
Ptnml(0-2): 178, 7371, 16478, 7641, 220
Passed LTC:
https://tests.stockfishchess.org/tests/view/673b2e2a86d5ee47d953f14b
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 156960 W: 39999 L: 39435 D: 77526
Ptnml(0-2): 96, 16965, 43803, 17511, 105
closes https://github.com/official-stockfish/Stockfish/pull/5686
Bench: 867931
2024-11-22 23:29:37 +01:00
Michael Chaly and Disservin
f129bf0de9
Tweak statscore for captures
...
Followup of a recent patch that separated statscore for captures and non-captures.
Lower value that we subtract from statscore if a move is a capture.
Passed STC:
https://tests.stockfishchess.org/tests/view/67385b6786d5ee47d953eeba
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 50592 W: 13223 L: 12888 D: 24481
Ptnml(0-2): 154, 5853, 12931, 6220, 138
Passed LTC:
https://tests.stockfishchess.org/tests/view/6739056e86d5ee47d953ef3f
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 23598 W: 6155 L: 5862 D: 11581
Ptnml(0-2): 16, 2466, 6543, 2757, 17
closes https://github.com/official-stockfish/Stockfish/pull/5682
Bench: 771180
2024-11-22 23:12:43 +01:00
Michael Chaly and Disservin
82b092ca48
Adjust statscore for captures
...
Instead of using quiet histories use capture history with a different
offset.
Passed STC:
https://tests.stockfishchess.org/tests/view/6731d5cc86d5ee47d953e719
LLR: 2.96 (-2.94,2.94) <0.00,2.00>
Total: 428896 W: 111160 L: 110269 D: 207467
Ptnml(0-2): 1220, 50296, 110534, 51169, 1229
Passed LTC:
https://tests.stockfishchess.org/tests/view/6733d9fd86d5ee47d953e962
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 105882 W: 26918 L: 26458 D: 52506
Ptnml(0-2): 66, 11430, 29482, 11904, 59
closes https://github.com/official-stockfish/Stockfish/pull/5679
Bench: 840721
2024-11-13 20:35:02 +01:00
Michael Chaly and Disservin
ecf5646f6e
Refine definition of improving
...
This patch also allows improving flag to be true if static evaluation of
the position is good enough.
Passed STC:
https://tests.stockfishchess.org/tests/view/6720906086d5ee47d953d4d0
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 34816 W: 9172 L: 8858 D: 16786
Ptnml(0-2): 113, 3988, 8887, 4312, 108
Passed LTC:
https://tests.stockfishchess.org/tests/view/6721162686d5ee47d953d597
LLR: 2.96 (-2.94,2.94) <0.50,2.50>
Total: 145374 W: 37118 L: 36574 D: 71682
Ptnml(0-2): 91, 15875, 40212, 16417, 92
closes https://github.com/official-stockfish/Stockfish/pull/5662
Bench: 1518856
2024-11-13 20:08:14 +01:00
Michael Chaly and Disservin
8ef403c786
Small cleanup for stats adjustments
...
After some simplifications bonuses and maluses are the same for quiet
and non-quiet moves so it makes no sense to use quietMoveBonus/Malus,
instead use just bonus/malus.
closes https://github.com/official-stockfish/Stockfish/pull/5649
No functional change
2024-10-31 09:26:00 +01:00
Michael Chaly and Disservin
9766db8139
Make low ply history size fixed
...
Size of low ply history should always be the same, so ensure it.
closes https://github.com/official-stockfish/Stockfish/pull/5630
No functional change
2024-10-12 16:40:55 +02:00
Michael Chaly and Joost VandeVondele
7ac745a736
Refactor root history into low ply history
...
This patch changes root history to low ply history - butterfly history for plies < 4.
Doubles weight of this history for root, latter plies have lesser effect.
Passed STC:
https://tests.stockfishchess.org/tests/view/66f77d2386d5ee47d953b65d
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 180992 W: 47362 L: 46830 D: 86800
Ptnml(0-2): 554, 21499, 45928, 21891, 624
Passed LTC:
https://tests.stockfishchess.org/tests/view/66fb557986d5ee47d953b8e5
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 42462 W: 11013 L: 10682 D: 20767
Ptnml(0-2): 33, 4518, 11795, 4855, 30
closes https://github.com/official-stockfish/Stockfish/pull/5614
Bench 1264335
2024-10-04 08:32:21 +02:00
Michael Chaly and Disservin
240a5b1c72
Introduce separate butterfly history table for sorting root moves
...
Idea of this patch comes from the fact that current history heuristics
are mostly populated by low depth entries since our stat bonus reaches
maximum value at depth 5-6 and number of low depth nodes is much bigger
than number of high depth nodes. But it doesn't make a whole lost of
sense to use this low-depth centered histories to sort moves at root.
Current patch introduces special history table that is used exclusively
at root, it remembers which quiet moves were good and which quiet moves
were not good there and uses this information for move ordering.
Passed STC:
https://tests.stockfishchess.org/tests/view/66dda74adc53972b68218cc9
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 127680 W: 33579 L: 33126 D: 60975
Ptnml(0-2): 422, 15098, 32391, 15463, 466
Passed LTC:
https://tests.stockfishchess.org/tests/view/66dead2adc53972b68218d34
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 381978 W: 96958 L: 95923 D: 189097
Ptnml(0-2): 277, 42165, 105089, 43162, 296
closes https://github.com/official-stockfish/Stockfish/pull/5595
Bench: 1611283
2024-09-17 20:54:02 +02:00
Michael Chaly and Disservin
a8cb002038
Simplify ttmove reduction
...
Remove condition that clamps reductions for tt move.
Passed STC:
https://tests.stockfishchess.org/tests/view/66d5f1239de3e7f9b33d14b0
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 91136 W: 23805 L: 23646 D: 43685
Ptnml(0-2): 334, 10328, 24066, 10525, 315
Passed LTC:
https://tests.stockfishchess.org/tests/view/66d7c5889de3e7f9b33d1721
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 139242 W: 35130 L: 35030 D: 69082
Ptnml(0-2): 78, 15200, 38986, 15258, 99
closes https://github.com/official-stockfish/Stockfish/pull/5574
Bench: 1268715
2024-09-09 18:02:32 +02:00
Michael Chaly and Disservin
607c3e404f
Remove unneeded depth tracking in qsearch
...
Since simplification of quiet checks in qsearch this depth isn't used by
any function at all apart movepicker, which also doesn't use passed
qsearch depth in any way, so can be removed. No functional change.
closes https://github.com/official-stockfish/Stockfish/pull/5514
No functional change
2024-07-28 22:18:33 +02:00
Michael Chaly and Joost VandeVondele
836154acb5
Introduce pre-qsearch ttmove extensions at pv nodes
...
The idea is that we are about to dive into qsearch (next search depth is <= 0)
but since we have the move in transposition table we should extend that move
and evaluate it with more precise search - because branch seems important.
Passed STC:
https://tests.stockfishchess.org/tests/view/6699d2564ff211be9d4ec488
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 83104 W: 21789 L: 21401 D: 39914
Ptnml(0-2): 293, 9748, 21128, 10044, 339
Passed LTC:
https://tests.stockfishchess.org/tests/view/669b3f1a4ff211be9d4ec602
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 136098 W: 34636 L: 34111 D: 67351
Ptnml(0-2): 105, 14882, 37550, 15407, 105
closes https://github.com/official-stockfish/Stockfish/pull/5512
bench 1526129
2024-07-23 19:24:00 +02:00
Michael Chaly and Joost VandeVondele
a8401e803d
Adjust bonus to move that caused a fail low
...
This is an elo gainer and simultaneously a minor logical fix to bonuses that caused a fail low.
It increases maximum of statscore based subtraction - but disallows negative bonuses.
Passed STC:
https://tests.stockfishchess.org/tests/view/66955e6f4ff211be9d4ec063
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 44640 W: 11805 L: 11472 D: 21363
Ptnml(0-2): 166, 5178, 11335, 5439, 202
Passed LTC:
https://tests.stockfishchess.org/tests/view/66963fde4ff211be9d4ec190
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 72288 W: 18478 L: 18082 D: 35728
Ptnml(0-2): 50, 7919, 19825, 8285, 65
closes https://github.com/official-stockfish/Stockfish/pull/5494
Bench: 1477054
2024-07-19 08:41:38 +02:00
Michael Chaly and Joost VandeVondele
de2bf1a186
Remove quiet history pruning depth limit
...
This patch removes lmrDepth limit for quiet moves history based pruning.
Previously removal of this type of depth limits was considered bad because it
was performing bad for matetrack - but with this pruning heuristic this
shouldn't be that bad because it's "naturally" depth limited by history
threshold and should be completely disabled at depth >= 15 or so. Also this
heuristic in previous years was known to scale non-linearly - bigger lmrDepth
thresholds were better at longer time controls and removing it completely
probably should scale pretty well.
Passed STC:
https://tests.stockfishchess.org/tests/view/6692b89b4ff211be9d4eab21
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 114464 W: 29675 L: 29545 D: 55244
Ptnml(0-2): 372, 12516, 31329, 12640, 375
Passed LTC:
https://tests.stockfishchess.org/tests/view/6692c4554ff211be9d4eab3d
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 67746 W: 17182 L: 17014 D: 33550
Ptnml(0-2): 28, 6993, 19652, 7183, 17
closes https://github.com/official-stockfish/Stockfish/pull/5485
Bench: 1250388
2024-07-15 13:35:06 +02:00
Michael Chaly and Joost VandeVondele
930915de90
Decrease delta
...
Decrease delta in aspiration windows - both initial value and quadratic
function of previous best value.
Passed STC:
https://tests.stockfishchess.org/tests/view/6691a52ec6827afcdcee1569
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 55456 W: 14449 L: 14107 D: 26900
Ptnml(0-2): 174, 6416, 14193, 6784, 161
Passed LTC:
https://tests.stockfishchess.org/tests/view/6691aac1c6827afcdcee1625
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 107940 W: 27530 L: 27065 D: 53345
Ptnml(0-2): 52, 11787, 29840, 12226, 65
closes https://github.com/official-stockfish/Stockfish/pull/5479
bench 1547707
2024-07-15 13:22:31 +02:00
Michael Chaly and Joost VandeVondele
eac2d080a3
Further simplify stat bonuses
...
Based on recent simplification by linrock Since it completely removed any
special bonuses based on values difference and made it flat stat_bonus(depth +
1) I got an idea that we might as well remove all (depth + 1) bonuses and make
them usual depth bonuses. Also removes weird negative bonus for depth 1 as a
side effect.
Passed STC:
https://tests.stockfishchess.org/tests/view/6689d817eca84f4d25863746
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 18080 W: 4789 L: 4552 D: 8739
Ptnml(0-2): 46, 1987, 4727, 2244, 36
Passed LTC:
https://tests.stockfishchess.org/tests/view/6689daa4eca84f4d258639d7
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 109062 W: 27548 L: 27417 D: 54097
Ptnml(0-2): 58, 11983, 30293, 12164, 33
Passed direct LTC vs linrock patch:
https://tests.stockfishchess.org/tests/view/668a46f8eca84f4d25866fe9
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 100002 W: 25351 L: 25209 D: 49442
Ptnml(0-2): 54, 11119, 27529, 11229, 70
closes https://github.com/official-stockfish/Stockfish/pull/5461
Bench 1175744
2024-07-09 18:41:36 +02:00
Michael Chaly and Joost VandeVondele
75c8cb2c2f
Adjust usage of previous statscore in bonus assignments
...
This patch adjusts usage of previous statscore for bonus assginments - allowing
it for any statscores and clamping it to wider range.
Passed STC:
https://tests.stockfishchess.org/tests/view/66892e76e59d990b103f6a91
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 431520 W: 111767 L: 110872 D: 208881
Ptnml(0-2): 1180, 51165, 110133, 52144, 1138
Passed LTC:
https://tests.stockfishchess.org/tests/view/66897176e59d990b103f9605
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 143184 W: 36463 L: 35929 D: 70792
Ptnml(0-2): 55, 15540, 39863, 16084, 50
closes https://github.com/official-stockfish/Stockfish/pull/5455
bench 1330556
2024-07-09 18:29:09 +02:00
Michael Chaly and Joost VandeVondele
7b49f9dd70
Tweak multicut
...
This patch is an original patch by author of Altair
(https://github.com/Alex2262/AltairChessEngine ) chess engine.
It allows to produce more aggressive multicut compared to master by changing
condition it needs to fulfil and also returns bigger value. Also has applied
matetrack fix on top.
Passed STC:
https://tests.stockfishchess.org/tests/view/667223ab602682471b0650e2
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 50048 W: 13200 L: 12860 D: 23988
Ptnml(0-2): 181, 5822, 12679, 6160, 182
Passed LTC:
https://tests.stockfishchess.org/tests/view/6672f777602682471b06515d
LLR: 2.97 (-2.94,2.94) <0.50,2.50>
Total: 706380 W: 179707 L: 177981 D: 348692
Ptnml(0-2): 656, 79250, 191665, 80950, 669
closes https://github.com/official-stockfish/Stockfish/pull/5421
bench 1148966
2024-07-01 19:56:38 +02:00
Michael Chaly and Joost VandeVondele
783dfc2eb2
Adjust return bonus from tt cutoffs at fail highs
...
This is reintroduction of the recently simplified logic - if positive tt cutoff
occurs return not a tt value but smth between it and beta. Difference is that
instead of static linear combination there we use basically the same formula as
we do in the main search - with the only difference being using tt depth
instead of depth, which makes a lot of sense.
Passed STC:
https://tests.stockfishchess.org/tests/view/665b3a34f4a1fd0c208ea870
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 54944 W: 14239 L: 13896 D: 26809
Ptnml(0-2): 151, 6407, 14008, 6760, 146
Passed LTC:
https://tests.stockfishchess.org/tests/view/665b520011645bd3d3fac341
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 90540 W: 23070 L: 22640 D: 44830
Ptnml(0-2): 39, 9903, 24965, 10315, 48
closes https://github.com/official-stockfish/Stockfish/pull/5336
bench 1381237
2024-06-01 20:02:09 +02:00
Michael Chaly and Disservin
b280d2f065
Allow tt cutoffs for shallower depths in certain conditions
...
Current master allows tt cutoffs only when depth
from tt is strictly greater than current node
depth. This patch also allows them when it's equal
and if tt value is lower or equal to beta.
Passed STC:
https://tests.stockfishchess.org/tests/view/66578e2e6b0e318cefa8d447
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 26592 W: 6944 L: 6645 D: 13003
Ptnml(0-2): 67, 3039, 6795, 3318, 77
Passed LTC:
https://tests.stockfishchess.org/tests/view/6657f46b6b0e318cefa8d7e9
LLR: 2.96 (-2.94,2.94) <0.50,2.50>
Total: 142572 W: 36315 L: 35776 D: 70481
Ptnml(0-2): 70, 15666, 39288, 16179, 83
closes https://github.com/official-stockfish/Stockfish/pull/5314
Bench: 1368486
2024-05-30 22:54:23 +02:00
Michael Chaly and Joost VandeVondele
daf9787de1
Rescale pawn history updates
...
This patch is somewhat of a continuation of recent pawn history gainers.
It makes pawn history updates after search twice smaller. Since on average they make pawn history more negative offset is changed to lower value to remain average value approximately the same.
https://tests.stockfishchess.org/tests/view/664b3af9830eb9f886614aab
Passed STC:
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 170464 W: 44239 L: 43724 D: 82501
Ptnml(0-2): 523, 20278, 43128, 20767, 536
Passed LTC against pending PR :
https://tests.stockfishchess.org/tests/view/664b8c58830eb9f886614b64
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 98178 W: 25015 L: 24569 D: 48594
Ptnml(0-2): 48, 10769, 27005, 11223, 44
closes https://github.com/official-stockfish/Stockfish/pull/5275
Bench: 1343175
2024-05-21 08:36:32 +02:00
Michael Chaly and Joost VandeVondele
0c797367a3
Update correction history in case of successful null move pruning
...
Since null move pruning uses the same position it makes some sense to try to update correction history there in case of fail high.
Update value is 4 times less than normal update.
Passed STC:
https://tests.stockfishchess.org/tests/view/664a011cae57c1758ac5b4dd
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 419360 W: 108390 L: 107505 D: 203465
Ptnml(0-2): 1416, 49603, 106724, 50554, 1383
Passed LTC:
https://tests.stockfishchess.org/tests/view/664a53d95fc7b70b8817c65b
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 193518 W: 49076 L: 48434 D: 96008
Ptnml(0-2): 89, 21335, 53263, 21989, 83
closes https://github.com/official-stockfish/Stockfish/pull/5272
bench 1301487
2024-05-21 08:17:20 +02:00
Michael Chaly and Joost VandeVondele
4a66a7c9ca
Do more aggressive pawn history updates
...
Tweak of recent patch that made pawn history to update for move that caused a fail low - and setting up default value of it to -900. This patch makes it more aggressive - twice bigger updates and default value -1100.
Passed STC:
https://tests.stockfishchess.org/tests/view/6648c5d4308cceea45533b5d
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 235200 W: 61090 L: 60476 D: 113634
Ptnml(0-2): 763, 27952, 59651, 28376, 858
Passed LTC:
https://tests.stockfishchess.org/tests/view/664a1008ae57c1758ac5b523
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 20076 W: 5193 L: 4908 D: 9975
Ptnml(0-2): 7, 2105, 5534, 2380, 12
closes https://github.com/official-stockfish/Stockfish/pull/5268
Bench: 1590474
2024-05-21 08:07:22 +02:00
Michael Chaly and Disservin
9e45644c50
Add extra bonus to pawn history for a move that caused a fail low
...
Basically the same idea as it is for continuation/main history, but it
has some tweaks.
1) it has * 2 multiplier for bonus instead of full/half bonus - for
whatever reason this seems to work better;
2) attempts with this type of big bonuses scaled somewhat poorly (or
were unlucky at longer time controls), but after measuring the fact
that average value of pawn history in LMR after adding this bonuses
increased by substantial number (for multiplier 1,5 it increased by
smth like 400~ from 8192 cap) attempts were made to make default pawn
history negative to compensate it - and version with multiplier 2 and
initial fill value -900 passed.
Passed STC:
https://tests.stockfishchess.org/tests/view/66424815f9f4e8fc783cba59
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 115008 W: 30001 L: 29564 D: 55443
Ptnml(0-2): 432, 13629, 28903, 14150, 390
Passed LTC:
https://tests.stockfishchess.org/tests/view/6642f5437134c82f3f7a3ffa
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 56448 W: 14432 L: 14067 D: 27949
Ptnml(0-2): 36, 6268, 15254, 6627, 39
Bench: 1857237
2024-05-15 16:15:15 +02:00
Michael Chaly and Joost VandeVondele
d3f081ed8a
Adjust standpat return value in qsearch
...
Instead of returning value itself return value between it and beta for non pv nodes - analogous to what we do after actual search there.
Passed STC:
https://tests.stockfishchess.org/tests/view/663cb1b4c0b75d7f7b98188e
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 131552 W: 34131 L: 33673 D: 63748
Ptnml(0-2): 420, 15446, 33600, 15876, 434
Passed LTC:
https://tests.stockfishchess.org/tests/view/663cda5dc0b75d7f7b981c6f
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 282798 W: 71658 L: 70833 D: 140307
Ptnml(0-2): 112, 31187, 77979, 32006, 115
closes https://github.com/official-stockfish/Stockfish/pull/5233
Bench: 1606672
2024-05-13 07:22:11 +02:00
Michael Chaly and Joost VandeVondele
23439e4096
Remove conthist 3 from moves loop pruning
...
Followup to previous gainer that made it twice less impactful there - this patch removes it entirely as a simplification.
Passed STC:
https://tests.stockfishchess.org/tests/view/6637aa7e9819650825aa93e0
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 26208 W: 6930 L: 6694 D: 12584
Ptnml(0-2): 113, 2997, 6652, 3225, 117
Passed LTC:
https://tests.stockfishchess.org/tests/view/66383cba493aaaf4b7ea90c2
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 67866 W: 17294 L: 17118 D: 33454
Ptnml(0-2): 46, 7627, 18415, 7795, 50
closes https://github.com/official-stockfish/Stockfish/pull/5221
Bench: 2691699
2024-05-09 08:56:36 +02:00
Michael Chaly and Joost VandeVondele
3b4ddf4ae6
Simplify away conthist 3 from statscore
...
Following previous elo gainer that gained by making conthist 3 less important in pruning this patch simplifies away this history from calculation of statscore.
Passed STC:
https://tests.stockfishchess.org/tests/view/6637aa7e9819650825aa93e0
LLR: 3.00 (-2.94,2.94) <-1.75,0.25>
Total: 35392 W: 9352 L: 9120 D: 16920
Ptnml(0-2): 141, 4145, 8888, 4385, 137
Passed LTC:
https://tests.stockfishchess.org/tests/view/66383cd8493aaaf4b7ea90c5
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 33948 W: 8714 L: 8503 D: 16731
Ptnml(0-2): 39, 3701, 9270, 3938, 26
closes https://github.com/official-stockfish/Stockfish/pull/5220
Bench: 2508571
2024-05-09 08:52:06 +02:00
Michael Chaly and Joost VandeVondele
d1b8d8bab3
Refactor quiet moves pruning in qsearch
...
Make it formula more in line with what we use in search - current formula is more or less the one we used years ago for search but since then it was remade, this patch remakes qsearch formula to almost exactly the same as we use in search - with sum of conthist 0, 1 and pawn structure history.
Passed STC:
https://tests.stockfishchess.org/tests/view/6639c8421343f0cb16716206
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 84992 W: 22414 L: 22019 D: 40559
Ptnml(0-2): 358, 9992, 21440, 10309, 397
Passed LTC:
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 119136 W: 30407 L: 29916 D: 58813
Ptnml(0-2): 46, 13192, 32622, 13641, 67
closes https://github.com/official-stockfish/Stockfish/pull/5224
Bench: 2138659
2024-05-09 08:33:07 +02:00
Michael Chaly and Joost VandeVondele
f161261245
Adjust history usage in moves loop pruning
...
After experiments with conthist 5 addition failed really bad divions by 2 passed as a gainer.
Passed STC:
https://tests.stockfishchess.org/tests/view/6636d7114b68b70d858035ce
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 35936 W: 9287 L: 8976 D: 17673
Ptnml(0-2): 81, 4129, 9234, 4446, 78
Passed LTC:
https://tests.stockfishchess.org/tests/view/6636ddb64b68b70d858040a8
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 82428 W: 21035 L: 20622 D: 40771
Ptnml(0-2): 29, 8985, 22775, 9394, 31
closes https://github.com/official-stockfish/Stockfish/pull/5217
Bench: 2309253
2024-05-05 13:06:22 +02:00
Michael Chaly and Joost VandeVondele
351a2e22dd
Add extra bonuses to some moves that forced a fail low
...
The previous patch on this idea was giving bonuses to this moves if best value of search is far below current static evaluation.
This patch does similar thing but adds extra bonus when best value of search is far below static evaluation before previous move.
Passed STC:
https://tests.stockfishchess.org/tests/view/66355fc819566d64b481d6a4
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 454144 W: 116575 L: 115656 D: 221913
Ptnml(0-2): 1060, 53410, 117215, 54325, 1062
Passed LTC:
https://tests.stockfishchess.org/tests/view/6635c61a73559a8aa858012d
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 136578 W: 34858 L: 34335 D: 67385
closes https://github.com/official-stockfish/Stockfish/pull/5209
Bench: 1614825
2024-05-05 12:42:30 +02:00
Michael Chaly and Joost VandeVondele
9021a61807
Trivial cleanup
...
Make naming and declaration of futilityValue in search consistent between different places.
closes https://github.com/official-stockfish/Stockfish/pull/5165
No functional change.
2024-04-21 14:35:54 +02:00
Michael Chaly and Joost VandeVondele
0ef5d05102
Adjust best value after a pruned quiet move
...
Logic somewhat similar to how we adjust best value after pruned captures
in qsearch, but in search this patch does it after pruned quiet moves
and also to not full scale of futility value but to smth in between
best value and futility value.
Passed STC:
https://tests.stockfishchess.org/tests/view/6601cf900ec64f0526c55c30
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 59936 W: 15722 L: 15369 D: 28845
Ptnml(0-2): 182, 7097, 15112, 7340, 237
Passed LTC:
https://tests.stockfishchess.org/tests/view/66029b2d0ec64f0526c566f1
LLR: 2.96 (-2.94,2.94) <0.50,2.50>
Total: 118362 W: 29953 L: 29460 D: 58949
Ptnml(0-2): 68, 13159, 32249, 13622, 83
closes https://github.com/official-stockfish/Stockfish/pull/5141
bench 1772608
2024-03-29 10:15:17 +01:00
Michael Chaly and Disservin
ed60460004
Clamp history bonus to stats range
...
Before, one always had to keep track of the bonus one assigns to a history to stop
the stats from overflowing. This is a quality of life improvement. Since this would often go unnoticed during benching.
Passed non-regression bounds:
https://tests.stockfishchess.org/tests/view/65ef2af40ec64f0526c44cbc
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 179232 W: 46513 L: 46450 D: 86269
Ptnml(0-2): 716, 20323, 47452, 20432, 693
closes https://github.com/official-stockfish/Stockfish/pull/5116
No functional change
2024-03-20 16:14:00 +01:00
Michael Chaly and Disservin
ee2ee6bdc4
Give more bonuses to quiet move that caused a fail low
...
Give extra bonus if search result is far below static evaluation of
position.
Passed STC:
https://tests.stockfishchess.org/tests/view/65edf1250ec64f0526c43787
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 90816 W: 23713 L: 23307 D: 43796
Ptnml(0-2): 401, 10725, 22742, 11147, 393
Passed LTC:
https://tests.stockfishchess.org/tests/view/65ef5ed70ec64f0526c450af
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 66618 W: 16950 L: 16565 D: 33103
Ptnml(0-2): 35, 7372, 18139, 7699, 64
closes https://github.com/official-stockfish/Stockfish/pull/5111
Bench: 2002517
2024-03-14 22:08:48 +01:00
Michael Chaly and Disservin
6136d094c5
Introduce double extensions for PV nodes
...
Our double/triple extensions were allowed only for non-pv nodes. This
patch allows them to be done for PV nodes, with some stricter
conditions.
Passed STC:
https://tests.stockfishchess.org/tests/view/65d657ec1d8e83c78bfddab8
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 339424 W: 88097 L: 87318 D: 164009
Ptnml(0-2): 1573, 39935, 85729, 41090, 1385
Passed LTC:
https://tests.stockfishchess.org/tests/view/65dd63824b19edc854ebc433
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 459564 W: 115812 L: 114614 D: 229138
Ptnml(0-2): 248, 51441, 125173, 52705, 215
closes https://github.com/official-stockfish/Stockfish/pull/5093
Bench: 1714391
2024-03-07 19:56:30 +01:00
Michael Chaly and Disservin
91a4cea437
Adjust best value in main search depending on depth
...
This patch does similar thing to how it's done for
qsearch - in case of fail high adjust result to
lower value. Difference is that it is done only
for non-pv nodes and it's depth dependent - so
lower depth entries will have bigger adjustment
and higher depth entries will have smaller
adjustment.
Passed STC:
https://tests.stockfishchess.org/tests/view/65c3c0cbc865510db0283b21
LLR: 2.96 (-2.94,2.94) <0.00,2.00>
Total: 112032 W: 29142 L: 28705 D: 54185
Ptnml(0-2): 479, 13152, 28326, 13571, 488
Passed LTC:
https://tests.stockfishchess.org/tests/view/65c52e62c865510db02855d5
LLR: 2.96 (-2.94,2.94) <0.50,2.50>
Total: 132480 W: 33457 L: 32936 D: 66087
Ptnml(0-2): 67, 14697, 36222, 15156, 98
closes https://github.com/official-stockfish/Stockfish/pull/5047
Bench: 1168241
2024-02-11 19:53:45 +01:00
Michael Chaly and Disservin
37bd1e774e
Do more double extensions
...
Parameter tweak from Black Marlin chess engine. Choose a significantly
lower value that triggers in 95% of cases, compared to the usual 84% in
standard benchmark runs.
Since the introduction by
https://github.com/official-stockfish/Stockfish/commit/33a858eaa1f792b3413384a3d0993dba36aca92e
this constant has only decreased in value over time.
2-16-17-18-21-22-25-26-52-71-75-93-140
Failed STC really fast:
https://tests.stockfishchess.org/tests/view/65b11d05c865510db026df7b
LLR: -2.94 (-2.94,2.94) <0.00,2.00>
Total: 13216 W: 3242 L: 3485 D: 6489
Ptnml(0-2): 50, 1682, 3371, 1471, 34
Was reasonable at LTC:
https://tests.stockfishchess.org/tests/view/65b13e20c865510db026e210
Elo: 1.18 ± 1.5 (95%) LOS: 94.3%
Total: 50000 W: 12517 L: 12347 D: 25136
Ptnml(0-2): 31, 5598, 13579, 5754, 38
nElo: 2.45 ± 3.0 (95%) PairsRatio: 1.03
Passed VLTC with STC bounds:
https://tests.stockfishchess.org/tests/view/65b18870c865510db026e769
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 30456 W: 7726 L: 7448 D: 15282
Ptnml(0-2): 6, 3111, 8717, 3387, 7
Passed VVLTC with LTC bounds:
https://tests.stockfishchess.org/tests/view/65b20b95c865510db026eef0
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 36134 W: 9158 L: 8859 D: 18117
Ptnml(0-2): 3, 3455, 10850, 3758, 1
closes https://github.com/official-stockfish/Stockfish/pull/5013
Bench: 1503692
2024-01-26 20:55:16 +01:00
Michael Chaly and Disservin
6f9071c643
Tweak usage of correction history
...
Instead of using linear formula use quadratic one. Maximum impact of
correction history is doubled this way, it breaks even with previous
formula on half of maximum value.
Passed STC:
https://tests.stockfishchess.org/tests/view/659591e579aa8af82b95d7e8
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 225216 W: 57616 L: 57019 D: 110581
Ptnml(0-2): 747, 26677, 57201, 27198, 785
Passed LTC:
https://tests.stockfishchess.org/tests/view/6596ee0b79aa8af82b95f08a
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 73314 W: 18524 L: 18125 D: 36665
Ptnml(0-2): 41, 8159, 19875, 8524, 58
closes https://github.com/official-stockfish/Stockfish/pull/4967
Bench: 1464785
2024-01-07 13:37:28 +01:00
Michael Chaly and Disservin
b4d995d0d9
Introduce static evaluation correction history
...
Idea from Caissa (https://github.com/Witek902/Caissa ) chess engine.
With given pawn structure collect data with how often search result and by how
much it was better / worse than static evalution of position and use it to
adjust static evaluation of positions with given pawn structure. Details:
1. excludes positions with fail highs and moves producing it being a capture;
2. update value is function of not only difference between best value and static
evaluation but also is multiplied by linear function of depth;
3. maximum update value is maximum value of correction history divided by 2;
4. correction history itself is divided by 32 when applied so maximum value of
static evaluation adjustment is 32 internal units.
Passed STC:
https://tests.stockfishchess.org/tests/view/658fc7b679aa8af82b955cac
LLR: 2.96 (-2.94,2.94) <0.00,2.00>
Total: 128672 W: 32757 L: 32299 D: 63616
Ptnml(0-2): 441, 15241, 32543, 15641, 470
Passed LTC:
https://tests.stockfishchess.org/tests/view/65903f6979aa8af82b9566f1
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 97422 W: 24626 L: 24178 D: 48618
Ptnml(0-2): 41, 10837, 26527, 11245, 61
closes https://github.com/official-stockfish/Stockfish/pull/4950
Bench: 1157852
2023-12-31 20:00:06 +01:00
Michael Chaly and Disservin
f388e41809
Adjust value returned after TT cutoff
...
Instead of returning value from TT in case of a fail high return mix between it
and beta.
Passed STC:
https://tests.stockfishchess.org/tests/view/658465395457644dc98446c7
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 220704 W: 56404 L: 55811 D: 108489
Ptnml(0-2): 750, 26214, 55921, 26627, 840
Passed LTC:
https://tests.stockfishchess.org/tests/view/6585c3f55457644dc9845db9
LLR: 2.97 (-2.94,2.94) <0.50,2.50>
Total: 124980 W: 31169 L: 30658 D: 63153
Ptnml(0-2): 57, 14147, 33603, 14594, 89
closes https://github.com/official-stockfish/Stockfish/pull/4934
Bench: 1191093
2023-12-30 11:01:32 +01:00
Michael Chaly and Disservin
9be0360aa4
Adjust return value in qsearch after fail high
...
Instead of returning strict fail soft fail high return value between value from
search and beta (somewhat by analogy to futility pruning and probcut).
This seems to be somewhat depth sensitive heuristic which performed much worse
at LTC while performing much better at STC if it is more aggressive, passed
version is the least aggressive one.
Passed STC:
https://tests.stockfishchess.org/tests/view/657b06414d789acf40ab1475
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 212352 W: 53900 L: 53315 D: 105137
Ptnml(0-2): 809, 25236, 53520, 25783, 828
Passed LTC:
https://tests.stockfishchess.org/tests/view/657ce36f393ac02e79120a7c
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 319362 W: 79541 L: 78630 D: 161191
Ptnml(0-2): 202, 35839, 86709, 36708, 223
closes https://github.com/official-stockfish/Stockfish/pull/4928
Bench: 974739
2023-12-19 18:22:10 +01:00
d9ec82e743
Adjust stand pat in qsearch on pv nodes
...
Instead of immediately returning a fail high do this only at non-pv nodes, for
pv nodes adjust bestValue to value between alpha and beta and continue
searching. Idea is to do it the same way as it's done in search where we don't
return positive beta cutoffs after ttHits / zero window search at PvNodes and
instead fully search lines.
Passed STC:
https://tests.stockfishchess.org/tests/view/65739b0af09ce1261f122f33
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 189216 W: 48142 L: 47598 D: 93476
Ptnml(0-2): 584, 22463, 48051, 22845, 665
Passed LTC:
https://tests.stockfishchess.org/tests/view/657701214d789acf40aac194
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 82506 W: 20689 L: 20269 D: 41548
Ptnml(0-2): 56, 9236, 22268, 9618, 75
Two issues had to be resolved:
- in rare cases it set alpha to the same value as beta and thus broke some asserts;
- messed up with returning tb win values.
Fix passed non-regression LTC vs this patch:
https://tests.stockfishchess.org/tests/view/6578113b4d789acf40aad544
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 277308 W: 68839 L: 68880 D: 139589
Ptnml(0-2): 167, 31580, 75212, 31517, 178
closes https://github.com/official-stockfish/Stockfish/pull/4922
Bench: 1069503
Co-Authored-By: Muzhen Gaming <61100393+XInTheDark@users.noreply.github.com >
Co-Authored-By: Shahin M. Shahin <41402573+peregrineshahin@users.noreply.github.com >
Co-Authored-By: fffelix-huang <72808219+fffelix-huang@users.noreply.github.com >
2023-12-19 18:22:10 +01:00
Michael Chaly and Joost VandeVondele
b4b704e686
Update pawn history based on static eval difference
...
Use the same logic as in main history but with 1/4 multiplier.
Passed STC:
https://tests.stockfishchess.org/tests/view/653c1282cc309ae8395615bf
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 306624 W: 77811 L: 77094 D: 151719
Ptnml(0-2): 975, 36411, 77830, 37114, 982
Passed LTC:
https://tests.stockfishchess.org/tests/view/654258e2cc309ae83956818d
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 99150 W: 24681 L: 24228 D: 50241
Ptnml(0-2): 56, 11107, 26792, 11568, 52
closes https://github.com/official-stockfish/Stockfish/pull/4859
bench 1330590
2023-11-03 22:50:05 +01:00
Michael Chaly and Joost VandeVondele
38e830af4b
Use more continuation histories.
...
This patch allows stats updates and movepicker bonuses for continuation history 3 plies deep - so counter counter move.
Updates and movepicker usage are done with 1/4 multiplier compared to other histories.
Passed STC:
https://tests.stockfishchess.org/tests/view/6528f28d3125598fc7ebb5a3
LLR: 2.96 (-2.94,2.94) <0.00,2.00>
Total: 161344 W: 41369 L: 40868 D: 79107
Ptnml(0-2): 535, 18720, 41679, 19185, 553
Passed LTC:
https://tests.stockfishchess.org/tests/view/652a397a3125598fc7ebd1d6
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 48564 W: 12556 L: 12215 D: 23793
Ptnml(0-2): 25, 5149, 13595, 5486, 27
closes https://github.com/official-stockfish/Stockfish/pull/4827
bench 1327410
2023-10-14 16:52:35 +02:00
Michael Chaly and Disservin
ef22829616
Do more futility pruning in qsearch
...
This patch introduces a third futility pruning heuristic in qsearch. The idea is
that the static exchange evaluation is much worse than the difference between
futility base and alpha. Thus we can assume that the probability of the move
being good enough to beat alpha is low so it can be pruned.
Passed STC:
https://tests.stockfishchess.org/tests/view/64fc982a5dab775b5359dc83
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 36576 W: 9484 L: 9170 D: 17922
Ptnml(0-2): 121, 4119, 9495, 4431, 122
Passed LTC:
https://tests.stockfishchess.org/tests/view/64fcc7935dab775b5359e1a9
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 135408 W: 34556 L: 34041 D: 66811
Ptnml(0-2): 56, 14462, 38165, 14953, 68
closes https://github.com/official-stockfish/Stockfish/pull/4781
Bench: 1330793
2023-09-11 22:36:26 +02:00
Michael Chaly and Disservin
d97a02ea2b
Give extra bonus to main history for moves that caused a fail low. #4744
...
Current master gives this type of bonuses to continuation history, this patch also gives them to main history.
Passed STC:
https://tests.stockfishchess.org/tests/view/64d4802a5b17f7c21c0e27b3
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 480768 W: 122767 L: 121798 D: 236203
Ptnml(0-2): 1563, 56190, 123834, 57309, 1488
Passed LTC:
https://tests.stockfishchess.org/tests/view/64d7e4c05b17f7c21c0e7456
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 32052 W: 8329 L: 8022 D: 15701
Ptnml(0-2): 19, 3335, 9015, 3634, 23
closes https://github.com/official-stockfish/Stockfish/pull/4744
Bench: 1711793
2023-08-13 11:38:24 +02:00
Michael Chaly and Stéphane Nicolet
5c2111cc30
Adjust futility pruning base in qsearch
...
Current master used value from transposition table there if it existed,
this patch uses minimum between this tt value and the static eval instead
(this thus is closer to the main search function, which uses the static eval).
Passed STC:
https://tests.stockfishchess.org/tests/view/64cd57285b17f7c21c0d6a8c
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 252544 W: 64671 L: 64039 D: 123834
Ptnml(0-2): 839, 29207, 65575, 29785, 866
Passed LTC:
https://tests.stockfishchess.org/tests/view/64cf6c915b17f7c21c0d9fcb
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 60150 W: 15374 L: 15012 D: 29764
Ptnml(0-2): 24, 6321, 17024, 6681, 25
closes https://github.com/official-stockfish/Stockfish/pull/4725
Bench: 1573024
2023-08-07 07:24:11 +02:00
Michael Chaly and Joost VandeVondele
5ea1cbc778
Do more futility pruning for cutNodes that are not in TT
...
This is somewhat similar to IIR for cutnodes but instead of reducing
depth for cutnodes that don't have tt move we reduce margin multiplier
in futility pruning for cutnodes that are not in TT.
Passed STC:
https://tests.stockfishchess.org/tests/view/64b244b90cdec37b95734c5b
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 75552 W: 19404 L: 19029 D: 37119
Ptnml(0-2): 233, 8806, 19378, 9071, 288
Passed LTC:
https://tests.stockfishchess.org/tests/view/64b3ae5a0cdec37b95736516
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 104988 W: 27152 L: 26697 D: 51139
Ptnml(0-2): 41, 11259, 29446, 11700, 48
closes https://github.com/official-stockfish/Stockfish/pull/4700
bench 1727577
2023-07-19 21:40:38 +02:00
Michael Chaly and Joost VandeVondele
913574f421
Remove improvement variable
...
No longer used in a meaningful way.
Improve comments.
Closes https://github.com/official-stockfish/Stockfish/pull/4688
No functional change
2023-07-16 15:18:41 +02:00
Michael Chaly and Joost VandeVondele
ece90bca9c
Improve comments
...
Fix comments for IIR, also document non-linear scaling in extensions.
Also add explicitly the bench, to fix an issue after the last commit.
closes https://github.com/official-stockfish/Stockfish/pull/4614
bench 2370027
2023-06-12 21:17:31 +02:00
Michael Chaly and Joost VandeVondele
8dea070538
Move internal iterative reduction before probcut
...
This patch moves IIR before probcut which allows probcut
to be produced at lower depths. Comments in IIR are also slightly updated.
Passed STC:
https://tests.stockfishchess.org/tests/view/6472d604d29264e4cfa749fd
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 387616 W: 103295 L: 102498 D: 181823
Ptnml(0-2): 976, 42322, 106381, 43187, 942
Passed LTC:
https://tests.stockfishchess.org/tests/view/6475eb8c4a36543c4c9f42e8
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 202836 W: 54901 L: 54281 D: 93654
Ptnml(0-2): 85, 19609, 61422, 20205, 97
closes https://github.com/official-stockfish/Stockfish/pull/4597
bench 2551691
2023-06-04 23:12:23 +02:00
Michael Chaly and Joost VandeVondele
d99942f254
Small simplification for probcut in check
...
Remove depth condition from there as not longer needed.
Passed STC:
https://tests.stockfishchess.org/tests/view/647367cad29264e4cfa753e6
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 254336 W: 67830 L: 67847 D: 118659
Ptnml(0-2): 580, 28181, 69697, 28096, 614
Passed LTC:
https://tests.stockfishchess.org/tests/view/647576184a36543c4c9f3af7
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 80706 W: 22048 L: 21898 D: 36760
Ptnml(0-2): 28, 7721, 24712, 7857, 35
closes https://github.com/official-stockfish/Stockfish/pull/4594
bench 2381945
2023-05-31 09:06:30 +02:00
Michael Chaly and Joost VandeVondele
df0fb8471e
Small simplification in low depth pruning
...
Uncap low depth pruning lmr depth.
It's anyway capped for most cases apart from futility pruning for captures - removes one std::min call.
Passed STC:
https://tests.stockfishchess.org/tests/view/645e8fa6d55cccb2e64225a1
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 184064 W: 49039 L: 48982 D: 86043
Ptnml(0-2): 462, 20353, 50349, 20402, 466
Passed LTC:
https://tests.stockfishchess.org/tests/view/645f4d48d55cccb2e6423335
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 83886 W: 22613 L: 22465 D: 38808
Ptnml(0-2): 31, 8090, 25546, 8252, 24
closes https://github.com/official-stockfish/Stockfish/pull/4566
bench 3201883
2023-05-20 10:19:03 +02:00
Michael Chaly and Joost VandeVondele
65e2150501
Refine deeper post-lmr searches
...
This patch improves logic conditions for performing deeper searches after passed LMR.
Instead of exceeding alpha by some margin now it requires to exceed the
current best value - which may be lower than alpha (but never bigger since we
update alpha with bestvalue if it exceeds alpha).
Passed STC:
https://tests.stockfishchess.org/tests/view/6455f78008858de8313775b6
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 209344 W: 55993 L: 55448 D: 97903
Ptnml(0-2): 507, 22798, 57526, 23325, 516
Passed LTC:
https://tests.stockfishchess.org/tests/view/64572d46eb75932ccfebff97
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 66288 W: 17867 L: 17514 D: 30907
Ptnml(0-2): 21, 6240, 20269, 6593, 21
closes https://github.com/official-stockfish/Stockfish/pull/4559
bench 3808503
2023-05-07 22:36:57 +02:00
Michael Chaly and Joost VandeVondele
464ebdf127
Small cleanup
...
In search remove one condition check and reorder conditions. Removes some code.
Passed non-regression test:
https://tests.stockfishchess.org/tests/view/64548fa06206ee34ebf853ad
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 282976 W: 75327 L: 75374 D: 132275
Ptnml(0-2): 604, 29673, 80995, 29598, 618
closes https://github.com/official-stockfish/Stockfish/pull/4557
No functional change
2023-05-07 22:32:21 +02:00
Michael Chaly and Joost VandeVondele
2429e16289
Reduce more if current node has a lot of refuted moves.
...
This patch refines idea of cutoff count - in master we reduce more if current node has at least 4 moves that are refuted by search, this patch increases this count by 1 if refutation happened without having a tt move.
Passed STC:
https://tests.stockfishchess.org/tests/view/645363c36206ee34ebf8191d
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 67616 W: 18220 L: 17874 D: 31522
Ptnml(0-2): 142, 7346, 18504, 7656, 160
Passed LTC:
https://tests.stockfishchess.org/tests/view/6453a0ea6206ee34ebf82796
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 195228 W: 52741 L: 52140 D: 90347
Ptnml(0-2): 53, 18718, 59482, 19297, 64
closes https://github.com/official-stockfish/Stockfish/pull/4556
bench 3448916
2023-05-05 07:12:47 +02:00
Michael Chaly and Joost VandeVondele
acb0d204d5
Simplify stats assignment for Pv nodes
...
This patch is a simplification of my recent elo gainer.
Logically the Elo gainer didn't make much sense and this patch simplifies it into smth more logical.
Instead of assigning negative bonuses to all non-first moves that enter PV nodes
we assign positive bonuses in full depth search after LMR only for moves that
will result in a fail high - thus not assigning positive bonuses
for moves that will go to pv search - so doing "almost" the same as we do in master now for them.
Logic differs for some other moves, though, but this removes some lines of code.
Passed STC:
https://tests.stockfishchess.org/tests/view/642cf5cf77ff3301150dc5ec
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 409320 W: 109124 L: 109308 D: 190888
Ptnml(0-2): 1149, 45385, 111751, 45251, 1124
Passed LTC:
https://tests.stockfishchess.org/tests/view/642fe75d20eb941419bde200
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 260336 W: 70280 L: 70303 D: 119753
Ptnml(0-2): 99, 25236, 79528, 25199, 106
closes https://github.com/official-stockfish/Stockfish/pull/4522
Bench: 4286815
2023-04-12 20:45:34 +02:00
Michael Chaly and Joost VandeVondele
510aca1ef6
Assign negative stat bonuses for quiet moves at Pv nodes
...
This patch assigns negative stat bonuses for quiet moves
at pv nodes which are searched at depth greater than
this node assumes, so are extended.
Passed STC:
https://tests.stockfishchess.org/tests/view/6426198bdb43ab2ba6f9cfa2
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 548944 W: 147287 L: 146254 D: 255403
Ptnml(0-2): 1662, 59772, 150671, 60605, 1762
Passed LTC:
https://tests.stockfishchess.org/tests/view/642be4f177ff3301150d892d
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 93352 W: 25400 L: 24994 D: 42958
Ptnml(0-2): 44, 8817, 28547, 9225, 43
closes https://github.com/official-stockfish/Stockfish/pull/4495
bench 5044536
2023-04-05 08:23:54 +02:00
Michael Chaly and Joost VandeVondele
1b5738e0c9
Simplify statScore initialization
...
This patch simplifies initialization of statScore to "always set it up to 0" instead of setting it up to 0 two plies deeper.
Reason for why it was done in previous way partially was because of LMR usage of previous statScore which was simplified long time ago so it makes sense to make in more simple there.
Passed STC:
https://tests.stockfishchess.org/tests/view/641a86d1db43ab2ba6f7b31d
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 115648 W: 30895 L: 30764 D: 53989
Ptnml(0-2): 368, 12741, 31473, 12876, 366
Passed LTC:
https://tests.stockfishchess.org/tests/view/641b1c31db43ab2ba6f7d17a
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 175576 W: 47122 L: 47062 D: 81392
Ptnml(0-2): 91, 17077, 53390, 17141, 89
closes https://github.com/official-stockfish/Stockfish/pull/4460
bench 5081969
2023-03-25 09:22:25 +01:00
Michael Chaly and Joost VandeVondele
78532af9dc
Do more singular extensions
...
This patch continues trend of last VLTC tuning - as measured by dubslow
most of it gains was in lowering marging in calculation of singularBeta.
This patch is a manual adjustment on top of it - it lowers multiplier
of depth in calculation of singularBeta even further, from 2/3 to 1,5/2,5.
Was negative at STC:
https://tests.stockfishchess.org/tests/view/64089c632644b62c3393fc12
Elo: -2.49 +-1.7 (95%) LOS: 0.2%
Total: 40000 W: 10601 L: 10888 D: 18511
Ptnml(0-2): 123, 4580, 10875, 4305, 117
nElo: -5.03 +-3.4 (95%) PairsRatio: 0.94
Passed 180+1.8 SPRT:
https://tests.stockfishchess.org/tests/view/640096dae74a12625bcf3b33
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 160952 W: 43753 L: 43342 D: 73857
Ptnml(0-2): 25, 13984, 52039, 14411, 17
Passed 60+0.6 8 threads SPRT:
https://tests.stockfishchess.org/tests/view/640dca8e65775d3b539cb7f6
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 38824 W: 10825 L: 10554 D: 17445
Ptnml(0-2): 0, 2939, 13268, 3200, 5
closes https://github.com/official-stockfish/Stockfish/pull/4443
bench 4776866
2023-03-14 08:22:40 +01:00
Michael Chaly and Joost VandeVondele
39da50ed23
Do more negative extensions
...
This patch does negatively extend transposition table move if singular search failed and tt value is not bigger than alpha.
Logic is close to what we had before recent simplification of negative extensions but uses or condition instead of and condition.
Passed STC:
https://tests.stockfishchess.org/tests/view/6404c8102644b62c33934607
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 119040 W: 31841 L: 31416 D: 55783
Ptnml(0-2): 356, 13070, 32292, 13397, 405
Passed LTC:
https://tests.stockfishchess.org/tests/view/6405abda2644b62c33937119
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 47216 W: 12816 L: 12496 D: 21904
Ptnml(0-2): 12, 4500, 14286, 4776, 34
closes https://github.com/official-stockfish/Stockfish/pull/4430
bench 4747020
2023-03-08 07:16:09 +01:00
Michael Chaly and Joost VandeVondele
5c75c1c2fb
Fix duplicated moves generation in movepicker
...
in a some of cases movepicker returned some moves more than once which lead
to them being searched more than once. This bug was possible because of how
we use queen promotions - they are generated as a captures but are not
included in position function which checks if move is a capture. Thus if
any refutation (killer or countermove) was a queen promotion it was
searched twice - once as a capture and one as a refutation.
This patch affects various things, namely stats assignments for queen promotions
and other moves if best move is queen promotion,
also some heuristics in search and qsearch.
With this patch every queen promotion is now considered a capture.
After this patch number of found duplicated moves is 0 during normal 13 depth bench run.
Passed STC:
https://tests.stockfishchess.org/tests/view/63f77e01e74a12625bcd87d7
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 80920 W: 21455 L: 21289 D: 38176
Ptnml(0-2): 198, 8839, 22241, 8963, 219
Passed LTC:
https://tests.stockfishchess.org/tests/view/63f7e020e74a12625bcd9a76
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 89712 W: 23674 L: 23533 D: 42505
Ptnml(0-2): 24, 8737, 27202, 8860, 33
closes https://github.com/official-stockfish/Stockfish/pull/4405
bench 4681731
2023-03-05 16:06:03 +01:00
Michael Chaly and Joost VandeVondele
472e726bff
Search tuning at very long time control
...
This patch is a result of tuning session of approximately 100k games at 120+1.2.
Biggest changes are in extensions, stat bonus and depth reduction for nodes without a tt move.
Failed STC:
https://tests.stockfishchess.org/tests/view/63f72c72e74a12625bcd7938
LLR: -2.94 (-2.94,2.94) <0.00,2.00>
Total: 13872 W: 3535 L: 3769 D: 6568
Ptnml(0-2): 56, 1621, 3800, 1419, 40
Close to neutral at LTC:
https://tests.stockfishchess.org/tests/view/63f738f5e74a12625bcd7b8a
Elo: 0.80 +-1.2 (95%) LOS: 90.0%
Total: 60000 W: 16213 L: 16074 D: 27713
Ptnml(0-2): 24, 5718, 18379, 5853, 26
nElo: 1.82 +-2.8 (95%) PairsRatio: 1.02
Passed 180+1.8 VLTC:
https://tests.stockfishchess.org/tests/view/63f868f3e74a12625bcdb33e
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 15864 W: 4449 L: 4202 D: 7213
Ptnml(0-2): 1, 1301, 5083, 1544, 3
Passed 60+0.6 8 threads SMP VLTC:
https://tests.stockfishchess.org/tests/view/63f8a5d6e74a12625bcdbdb3
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 6288 W: 1821 L: 1604 D: 2863
Ptnml(0-2): 0, 402, 2123, 619, 0
closes https://github.com/official-stockfish/Stockfish/pull/4406
bench 4705194
2023-02-24 20:14:44 +01:00
Michael Chaly and Joost VandeVondele
8f843633db
Cleanup and reorder in qsearch
...
This patch is a simplification / code normalisation in qsearch.
Adds steps in comments the same way we have in search;
Makes a separate "pruning" stage instead of heuristics randomly being spread over qsearch code;
Reorders pruning heuristics from least taxing ones to more taxing ones;
Removes repeated check for best value not being mated, instead uses 1 check - thus removes some lines of code.
Moves prefetch and move setup after pruning - makes no sense to do them if move will actually get pruned.
Passed non-regression test:
https://tests.stockfishchess.org/tests/view/63dd2c5ff9a50a69252c1413
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 113504 W: 29898 L: 29770 D: 53836
Ptnml(0-2): 287, 11861, 32327, 11991, 286
https://github.com/official-stockfish/Stockfish/pull/4382
Non-functional change.
2023-02-09 07:45:05 +01:00
Michael Chaly and Joost VandeVondele
1cdc0f78bd
Simplify usage of optimism in complexity
...
This patch removes one condition in optimism usage in complexity, now negative optimism also impacts it.
Passed STC:
https://tests.stockfishchess.org/tests/view/63d34f43721fe2bff692fb12
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 204920 W: 54343 L: 54309 D: 96268
Ptnml(0-2): 598, 22648, 55897, 22756, 561
Passed LTC:
https://tests.stockfishchess.org/tests/view/63d612a2a67dd929a556075c
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 200712 W: 53207 L: 53172 D: 94333
Ptnml(0-2): 58, 19664, 60901, 19651, 82
closes https://github.com/official-stockfish/Stockfish/pull/4377
bench 4204964
2023-02-03 20:10:08 +01:00
Michael Chaly and Joost VandeVondele
da8513f0ea
Do less SEE pruning in qsearch
...
Current master prunes all moves with negative SEE values in qsearch.
This patch sets constant negative threshold thus allowing some moves with negative SEE values to be searched.
Value of threshold is completely arbitrary and can be tweaked - also it as function of depth can be tried.
Original idea by author of Alexandria engine.
Passed STC
https://tests.stockfishchess.org/tests/view/63d79a59a67dd929a5564976
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 34864 W: 9392 L: 9086 D: 16386
Ptnml(0-2): 113, 3742, 9429, 4022, 126
Passed LTC
https://tests.stockfishchess.org/tests/view/63d8074aa67dd929a5565bc2
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 91616 W: 24532 L: 24126 D: 42958
Ptnml(0-2): 32, 8840, 27662, 9238, 36
closes https://github.com/official-stockfish/Stockfish/pull/4376
Bench: 4010877
2023-02-02 18:00:14 +01:00
Michael Chaly and Joost VandeVondele
d3860f8d5e
Rebalance usage of history heuristics in pruning
...
This patch has multiple effects:
* history heuristics sum in futility pruning now can't exceed some negative value so futility pruning for moves with negative histories should become slightly less aggressive;
* history heuristics are now used in SEE pruning for quiet moves;
Passed STC:
https://tests.stockfishchess.org/tests/view/63cde339c93e8828d0f02e3a
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 88424 W: 23681 L: 23303 D: 41440
Ptnml(0-2): 258, 9559, 24219, 9899, 277
Passed LTC:
https://tests.stockfishchess.org/tests/view/63ce9009c93e8828d0f04e4f
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 79536 W: 21223 L: 20843 D: 37470
Ptnml(0-2): 22, 7599, 24146, 7979, 22
closes https://github.com/official-stockfish/Stockfish/pull/4355
Bench: 4208265
2023-01-25 07:51:19 +01:00
Michael Chaly and Joost VandeVondele
39af98c807
Reintroduce doEvenDeeperSearch
...
This patch is basically the same as a reverted patch
but now has some guarding against search being stuck - the same
way as we do with double extensions. This should help with
search explosions - albeit slowly but they eventually should be resolved.
passed STC:
https://tests.stockfishchess.org/tests/view/639733d0b4e52c95053f3485
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 514048 W: 136423 L: 135435 D: 242190
Ptnml(0-2): 1425, 56945, 139420, 57685, 1549
passed LTC:
https://tests.stockfishchess.org/tests/view/639ab79b93ed41c57eded5c3
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 113800 W: 30642 L: 30190 D: 52968
Ptnml(0-2): 53, 11092, 34178, 11504, 73
closes https://github.com/official-stockfish/Stockfish/pull/4287
bench 3611278
2022-12-19 18:11:12 +01:00
Michael Chaly and Joost VandeVondele
219fa2f0a7
Do shallower search in case of lmr being not successful enough
...
In case of a move passing LMR but it results being not too far from
the current best search result produce a full depth search with reduced depth.
Original idea by lonfom169 .
Passed STC:
https://tests.stockfishchess.org/tests/view/6373409b54d69a2f33913fbd
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 169504 W: 45351 L: 44848 D: 79305
Ptnml(0-2): 598, 18853, 45353, 19344, 604
Passed LTC:
https://tests.stockfishchess.org/tests/view/6374c58528e3405283eb8d2d
LLR: 2.96 (-2.94,2.94) <0.50,2.50>
Total: 51144 W: 13802 L: 13471 D: 23871
Ptnml(0-2): 19, 4928, 15362, 5229, 34
closes https://github.com/official-stockfish/Stockfish/pull/4230
bench 4277005
2022-11-19 09:23:26 +01:00
Michael Chaly and Joost VandeVondele
4ec8945eaf
Use TT moves more often in qsearch
...
During the recapture phase of quiescence search (where we limit the generated moves to recaptures on the last seen capture square),
the move picker will now emit the tt move, even if the tt move is not a recapture.
Passed STC :
https://tests.stockfishchess.org/tests/view/6350df2928d3a71cb1eef838
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 90280 W: 24001 L: 23845 D: 42434
Ptnml(0-2): 273, 9779, 24941, 9813, 334
Passed LTC :
https://tests.stockfishchess.org/tests/view/6351308b28d3a71cb1ef06ce
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 104504 W: 27937 L: 27807 D: 48760
Ptnml(0-2): 54, 10378, 31260, 10504, 56
closes https://github.com/official-stockfish/Stockfish/pull/4206
Bench: 4540268
2022-10-23 20:22:04 +02:00
Michael Chaly and Joost VandeVondele
1591e5ac3b
Do less singular extensions for former PVnode
...
Patch is a reintroduction of logic what was simplified a while ago
in a slightly different form. Do bigger extension offset in
case of non-pv node having a pv.
passed STC
https://tests.stockfishchess.org/tests/view/631977c048f27688a06e66d5
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 23296 W: 6404 L: 6108 D: 10784
Ptnml(0-2): 88, 2539, 6118, 2795, 108
passed LTC
https://tests.stockfishchess.org/tests/view/631989cb48f27688a06e696c
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 235592 W: 63890 L: 63188 D: 108514
Ptnml(0-2): 275, 23392, 69804, 24006, 319
closes https://github.com/official-stockfish/Stockfish/pull/4159
Bench: 3993611
2022-09-11 14:15:54 +02:00
Michael Chaly and Joost VandeVondele
eaf2c8207f
Further LTC tuning of search parameters
...
Tuning done by bigpenor with some hand adjustments on top by Viz.
Had a good performance at fixed games 180+1.8:
https://tests.stockfishchess.org/tests/view/631836b437f41b13973d7da1
Elo: 1.35 +-1.2 (95%) LOS: 98.6%
Total: 60000 W: 16422 L: 16189 D: 27389
Ptnml(0-2): 39, 5335, 18992, 5622, 12
nElo: 3.13 +-2.8 (95%) PairsRatio: 1.05
Passed 60+0.6 8 threads SPRT:
https://tests.stockfishchess.org/tests/view/631ba0ff74bc4fe483a99db3
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 29712 W: 8301 L: 8039 D: 13372
Ptnml(0-2): 12, 2318, 9925, 2598, 3
closes https://github.com/official-stockfish/Stockfish/pull/4160
bench 3938073
2022-09-11 14:05:39 +02:00
Michael Chaly and Joost VandeVondele
5f290352cd
Simplify away smp adjustment in TT use
...
Passed STC
https://tests.stockfishchess.org/tests/view/62f7d81f23d42b50a8dab568
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 98160 W: 26307 L: 26165 D: 45688
Ptnml(0-2): 201, 10282, 27960, 10448, 189
Passed LTC
https://tests.stockfishchess.org/tests/view/62f8d1a623d42b50a8dad4fb
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 81544 W: 22346 L: 22200 D: 36998
Ptnml(0-2): 44, 7542, 25446, 7704, 36
closes https://github.com/official-stockfish/Stockfish/pull/4131
No functional change (single threaded).
2022-08-15 17:54:56 +02:00
Michael Chaly and Joost VandeVondele
582c88ee94
Do more TT cutoffs in case of exact bound
...
The idea is that these TT entries are considered move valuable in TT replacement scheme - they are always overwriting other entries. So it makes sence for them to produce more aggressive cutoffs.
passed STC
https://tests.stockfishchess.org/tests/view/62e4d407b383a712b1385410
LLR: 2.95 (-2.94,2.94) <0.00,2.50>
Total: 96632 W: 26045 L: 25659 D: 44928
Ptnml(0-2): 434, 10635, 25770, 11065, 412
passed LTC
https://tests.stockfishchess.org/tests/view/62e523e2b383a712b1386193
LLR: 2.94 (-2.94,2.94) <0.50,3.00>
Total: 77960 W: 21363 L: 20989 D: 35608
Ptnml(0-2): 190, 7591, 23009, 8035, 155
closes https://github.com/official-stockfish/Stockfish/pull/4114
bench 5820568
2022-07-31 11:03:28 +02:00
Michael Chaly and Joost VandeVondele
95d24b77df
Simplify away some unneeded code in time management
...
The lower bound of the clamp is never used since complexity can't be negative and thus is unneeded.
closes https://github.com/official-stockfish/Stockfish/pull/4105
No functional change
2022-07-13 18:00:39 +02:00
Michael Chaly and Joost VandeVondele
c2aaaa65f9
Simplify away FRC correction term
...
Since new net is trained partially using FRC data this part of adjustment that penalises bishops that are locked in the corner is no longer needed - net should "know" this things itself much better.
STC on FRC book :
https://tests.stockfishchess.org/tests/view/62c3031b9e7d9997a12d852f
LLR: 2.96 (-2.94,2.94) <-2.25,0.25>
Total: 22048 W: 3003 L: 2845 D: 16200
Ptnml(0-2): 96, 1778, 7149, 1874, 127
LTC on FRC book :
https://tests.stockfishchess.org/tests/view/62c32e939e7d9997a12d8c5e
LLR: 2.94 (-2.94,2.94) <-2.25,0.25>
Total: 36784 W: 3138 L: 3037 D: 30609
Ptnml(0-2): 36, 1842, 14537, 1939, 38
STC on DFRC book :
https://tests.stockfishchess.org/tests/view/62c32efb9e7d9997a12d8c6f
LLR: 2.94 (-2.94,2.94) <-2.25,0.25>
Total: 20424 W: 3903 L: 3721 D: 12800
Ptnml(0-2): 172, 1984, 5724, 2154, 178
LTC on DFRC book :
https://tests.stockfishchess.org/tests/view/62c358c79e7d9997a12d9319
LLR: 2.93 (-2.94,2.94) <-2.25,0.25>
Total: 53784 W: 7581 L: 7480 D: 38723
Ptnml(0-2): 87, 3887, 18856, 3962, 100
closes https://github.com/official-stockfish/Stockfish/pull/4101
bench 5182295
2022-07-05 13:55:50 +02:00
Michael Chaly and Joost VandeVondele
8fadbcf1b2
Add info about elo gained from some heuristics
...
Add info about qsearch and impact of main and continuation histories.
Based on these tests:
https://tests.stockfishchess.org/tests/view/62946ffcb0d5a7d1b780fc7e
https://tests.stockfishchess.org/tests/view/628facb71e7cd5f299669534
https://tests.stockfishchess.org/tests/view/628eade11e7cd5f299666f2e
closes https://github.com/official-stockfish/Stockfish/pull/4041
No functional change.
2022-06-02 07:43:14 +02:00
Michael Chaly and Joost VandeVondele
e41f727f0f
Simplify away best move count logic
...
the only place where it was used it was true with >99% probability so it seemed to not be doing much any more.
Passed STC:
https://tests.stockfishchess.org/tests/view/625f4778d00da81c22dd4c93
LLR: 2.95 (-2.94,2.94) <-2.25,0.25>
Total: 85152 W: 22487 L: 22406 D: 40259
Ptnml(0-2): 313, 9035, 23818, 9078, 332
Passed LTC:
https://tests.stockfishchess.org/tests/view/625ff1f1b03f22647441a215
LLR: 2.94 (-2.94,2.94) <-2.25,0.25>
Total: 66776 W: 17768 L: 17673 D: 31335
Ptnml(0-2): 46, 6200, 20792, 6313, 37
close https://github.com/official-stockfish/Stockfish/pull/3993
bench 7280798
2022-04-22 08:09:40 +02:00
Michael Chaly and Joost VandeVondele
08e0f52b77
In movepicker increase priority for moves that evade a capture
...
This idea is a mix of koivisto idea of threat history and heuristic that
was simplified some time ago in LMR - decreasing reduction for moves that evade a capture.
Instead of doing so in LMR this patch does it in movepicker - to do this it
calculates squares that are attacked by different piece types and pieces that are located
on this squares and boosts up weight of moves that make this pieces land on a square that is not under threat.
Boost is greater for pieces with bigger material values.
Special thanks to koivisto and seer authors for explaining me ideas behind threat history.
Passed STC:
https://tests.stockfishchess.org/tests/view/62406e473b32264b9aa1478b
LLR: 2.94 (-2.94,2.94) <0.00,2.50>
Total: 19816 W: 5320 L: 5072 D: 9424
Ptnml(0-2): 86, 2165, 5172, 2385, 100
Passed LTC:
https://tests.stockfishchess.org/tests/view/62407f2e3b32264b9aa149c8
LLR: 2.94 (-2.94,2.94) <0.50,3.00>
Total: 51200 W: 13805 L: 13500 D: 23895
Ptnml(0-2): 44, 5023, 15164, 5322, 47
closes https://github.com/official-stockfish/Stockfish/pull/3970
bench 7736491
2022-03-28 22:37:09 +02:00
Michael Chaly and Joost VandeVondele
eae0f8dd06
Decrease reductions in Lmr for some Pv nodes
...
This patch makes us reduce less in Lmr at pv nodes in case of static eval being far away from static evaluation of position.
Idea is that if it's the case then probably position is pretty complex so we can't be sure about how reliable LMR is so we need to reduce less.
Passed STC:
https://tests.stockfishchess.org/tests/view/6226276aa9d47c8160e81220
LLR: 2.94 (-2.94,2.94) <0.00,2.50>
Total: 262696 W: 69944 L: 69239 D: 123513
Ptnml(0-2): 1399, 29702, 68436, 30417, 1394
Passed LTC:
https://tests.stockfishchess.org/tests/view/6226b002a9d47c8160e82b91
LLR: 2.95 (-2.94,2.94) <0.50,3.00>
Total: 64008 W: 17320 L: 16982 D: 29706
Ptnml(0-2): 60, 6378, 18811, 6674, 81
closes https://github.com/official-stockfish/Stockfish/pull/3957
bench 6678390
2022-03-08 20:19:42 +01:00
Michael Chaly and Joost VandeVondele
27139dedac
Adjust usage of LMR for 2nd move in move ordering
...
Current master prohibits usage of LMR for 2nd move at rootNode. This patch also disables LMR for 2nd move not only at rootNode but also at first PvNode that is a reply to rootNode.
passed STC:
https://tests.stockfishchess.org/tests/view/620e8c9026f5b17ec885143a
LLR: 2.94 (-2.94,2.94) <0.00,2.50>
Total: 54096 W: 14305 L: 13996 D: 25795
Ptnml(0-2): 209, 6075, 14192, 6342, 230
passed LTC:
https://tests.stockfishchess.org/tests/view/620eb327b1792e8985f81fb8
LLR: 2.94 (-2.94,2.94) <0.50,3.00>
Total: 110864 W: 29602 L: 29156 D: 52106
Ptnml(0-2): 112, 11147, 32455, 11619, 99
closes https://github.com/official-stockfish/Stockfish/pull/3940
bench 6820724
2022-02-20 23:01:22 +01:00
Michael Chaly and Stéphane Nicolet
84b1940fca
Tune search at very long time control
...
This patch is a result of tuning done by user @candirufish after 150k games.
Since the tuned values were really interesting and touched heuristics
that are known for their non-linear scaling I decided to run limited
games LTC match, even if the STC test was really bad (which was expected).
After seeing the results of the LTC match, I also run a VLTC (very long
time control) SPRTtest, which passed.
The main difference is in extensions: this patch allows much more
singular/double extensions, both in terms of allowing them at lower
depths and with lesser margins.
Failed STC:
https://tests.stockfishchess.org/tests/view/620d66643ec80158c0cd3b46
LLR: -2.94 (-2.94,2.94) <0.00,2.50>
Total: 4968 W: 1194 L: 1398 D: 2376
Ptnml(0-2): 47, 633, 1294, 497, 13
Performed well at LTC in a fixed-length match:
https://tests.stockfishchess.org/tests/view/620d66823ec80158c0cd3b4a
ELO: 3.36 +-1.8 (95%) LOS: 100.0%
Total: 30000 W: 7966 L: 7676 D: 14358
Ptnml(0-2): 36, 2936, 8755, 3248, 25
Passed VLTC SPRT test:
https://tests.stockfishchess.org/tests/view/620da11a26f5b17ec884f939
LLR: 2.96 (-2.94,2.94) <0.50,3.00>
Total: 4400 W: 1326 L: 1127 D: 1947
Ptnml(0-2): 13, 309, 1348, 526, 4
closes https://github.com/official-stockfish/Stockfish/pull/3937
Bench: 6318903
2022-02-17 20:45:21 +01:00
Michael Chaly and Stéphane Nicolet
3ec6e1d245
Big search tuning (version 2)
...
One more tuning - this one includes newly introduced heuristics and
some other parameters that were not included in previous one. Result
of 400k games at 20+0.2 "as is". Tuning is continuing since there is
probably a lot more elo to gain.
STC:
https://tests.stockfishchess.org/tests/view/620782edd71106ed12a497d1
LLR: 2.99 (-2.94,2.94) <0.00,2.50>
Total: 38504 W: 10260 L: 9978 D: 18266
Ptnml(0-2): 142, 4249, 10230, 4447, 184
LTC:
https://tests.stockfishchess.org/tests/view/6207a243d71106ed12a49d07
LLR: 2.94 (-2.94,2.94) <0.50,3.00>
Total: 25176 W: 6793 L: 6546 D: 11837
Ptnml(0-2): 20, 2472, 7360, 2713, 23
closes https://github.com/official-stockfish/Stockfish/pull/3931
Bench: 4784796
2022-02-13 01:05:27 +01:00
Michael Chaly and Joost VandeVondele
b0b31558a2
Big search tuning
...
Most credits for this patch should go to @candirufish.
Based on his big search tuning (1M games at 20+0.1s)
https://tests.stockfishchess.org/tests/view/61fc7a6ed508ec6a1c9f4b7d
with some hand polishing on top of it, which includes :
a) correcting trend sigmoid - for some reason original tuning resulted in it being negative. This heuristic was proven to be worth some elo for years so reversing it sign is probably some random artefact;
b) remove changes to continuation history based pruning - this heuristic historically was really good at providing green STCs and then failing at LTC miserably if we tried to make it more strict, original tuning was done at short time control and thus it became more strict - which doesn't scale to longer time controls;
c) remove changes to improvement - not really indended :).
passed STC
https://tests.stockfishchess.org/tests/view/6203526e88ae2c84271c2ee2
LLR: 2.94 (-2.94,2.94) <0.00,2.50>
Total: 16840 W: 4604 L: 4363 D: 7873
Ptnml(0-2): 82, 1780, 4449, 2033, 76
passed LTC
https://tests.stockfishchess.org/tests/view/620376e888ae2c84271c35d4
LLR: 2.96 (-2.94,2.94) <0.50,3.00>
Total: 17232 W: 4771 L: 4542 D: 7919
Ptnml(0-2): 14, 1655, 5048, 1886, 13
closes https://github.com/official-stockfish/Stockfish/pull/3926
bench 5030992
2022-02-09 17:17:00 +01:00
Michael Chaly and Joost VandeVondele
08ac4e9db5
Do less depth reduction in null move pruning for complex positions
...
This patch makes us reduce less depth in null move pruning if complexity is high enough.
Thus, null move pruning now depends in two distinct ways on complexity,
while being the only search heuristic that exploits complexity so far.
passed STC
https://tests.stockfishchess.org/tests/view/61fde60fd508ec6a1c9f7754
LLR: 2.94 (-2.94,2.94) <0.00,2.50>
Total: 170000 W: 45555 L: 45027 D: 79418
Ptnml(0-2): 760, 19352, 44359, 19658, 871
passed LTC
https://tests.stockfishchess.org/tests/view/61fe91febf46cb834cbd5c90
LLR: 2.96 (-2.94,2.94) <0.50,3.00>
Total: 145272 W: 39182 L: 38651 D: 67439
Ptnml(0-2): 127, 14864, 42157, 15327, 161
closes https://github.com/official-stockfish/Stockfish/pull/3923
bench 4461945
2022-02-07 17:30:35 +01:00
Michael Chaly and Joost VandeVondele
4d3950c6eb
Reintroduce razoring
...
Razoring was simplified away some years ago, this patch reintroduces it in a slightly different form.
Now for low depths if eval is far below alpha we check if qsearch can push it above alpha - and if it can't we return a fail low.
passed STC
https://tests.stockfishchess.org/tests/view/61fbf968d508ec6a1c9f3274
LLR: 2.94 (-2.94,2.94) <0.00,2.50>
Total: 226120 W: 61106 L: 60472 D: 104542
Ptnml(0-2): 1118, 25592, 59080, 26078, 1192
passed LTC
https://tests.stockfishchess.org/tests/view/61fcc569d508ec6a1c9f5617
LLR: 2.94 (-2.94,2.94) <0.50,3.00>
Total: 113128 W: 30851 L: 30397 D: 51880
Ptnml(0-2): 114, 11483, 32926, 11917, 124
closes https://github.com/official-stockfish/Stockfish/pull/3921
bench 4684080
2022-02-05 07:40:21 +01:00
Michael Chaly and Joost VandeVondele
95d7369e54
Introduce movecount pruning for quiet check evasions in qsearch
...
Idea of this patch is that we usually don't consider quiet check evasions as "good" ones and prefer capture based ones instead. So it makes sense to think that if in qsearch 2 quiet check evasions failed to produce anything good 3rd and further ones wouldn't be good either.
passed STC
https://tests.stockfishchess.org/tests/view/61fc1b1ed508ec6a1c9f397c
LLR: 2.94 (-2.94,2.94) <0.00,2.50>
Total: 58800 W: 15947 L: 15626 D: 27227
Ptnml(0-2): 273, 6568, 15462, 6759, 338
passed LTC
https://tests.stockfishchess.org/tests/view/61fcc56dd508ec6a1c9f5619
LLR: 2.95 (-2.94,2.94) <0.50,3.00>
Total: 89544 W: 24208 L: 23810 D: 41526
Ptnml(0-2): 81, 9038, 26134, 9440, 79
closes https://github.com/official-stockfish/Stockfish/pull/3920
bench 4830082
2022-02-05 07:38:30 +01:00
Michael Chaly and Joost VandeVondele
50200de5af
Cleanup and update CPU contributors
...
closes https://github.com/official-stockfish/Stockfish/pull/3917
No functional change
2022-02-05 07:30:09 +01:00
Michael Chaly and Joost VandeVondele
90d051952f
Do stats updates after LMR for captures
...
Since captures that are in LMR use continuation histories of corresponding quiet moves it makes sense to update this histories if this capture passes LMR by analogy to existing logic for quiet moves.
Passed STC
https://tests.stockfishchess.org/tests/view/61f367eef7fba9f1a4f1318b
LLR: 2.94 (-2.94,2.94) <0.00,2.50>
Total: 208464 W: 56006 L: 55407 D: 97051
Ptnml(0-2): 964, 23588, 54655, 23935, 1090
Passed LTC
https://tests.stockfishchess.org/tests/view/61f41e34f7fba9f1a4f15241
LLR: 2.96 (-2.94,2.94) <0.50,3.00>
Total: 69144 W: 18793 L: 18441 D: 31910
Ptnml(0-2): 65, 6982, 20142, 7302, 81
closes https://github.com/official-stockfish/Stockfish/pull/3910
bench 4637392
2022-01-29 08:58:12 +01:00
Michael Chaly and Joost VandeVondele
8b4afcf8f7
Scale child node futility pruning with previous move history.
...
Idea is to do more futility pruning if previous move has bad histories and less if it has good histories.
passed STC
https://tests.stockfishchess.org/tests/view/61e3757fbabab931824e0db7
LLR: 2.96 (-2.94,2.94) <0.00,2.50>
Total: 156816 W: 42282 L: 41777 D: 72757
Ptnml(0-2): 737, 17775, 40913, 18212, 771
passed LTC
https://tests.stockfishchess.org/tests/view/61e43496928632f7813a5535
LLR: 2.95 (-2.94,2.94) <0.50,3.00>
Total: 349968 W: 94612 L: 93604 D: 161752
Ptnml(0-2): 300, 35934, 101550, 36858, 342
closes https://github.com/official-stockfish/Stockfish/pull/3903
bench 4720954
2022-01-25 07:27:52 +01:00
Michael Chaly and Joost VandeVondele
44b1ba89a9
Adjust pruning constants
...
This patch is a modification of original tuning done by vondele that failed yellow.
Value differences are divided by 2.
Passed STC
https://tests.stockfishchess.org/tests/view/61d918239fea7913d9c64cdf
LLR: 2.94 (-2.94,2.94) <0.00,2.50>
Total: 98968 W: 26248 L: 25858 D: 46862
Ptnml(0-2): 392, 11085, 26156, 11443, 408
Passed LTC
https://tests.stockfishchess.org/tests/view/61d99e3c9fea7913d9c663e4
LLR: 2.95 (-2.94,2.94) <0.50,3.00>
Total: 215232 W: 58191 L: 57492 D: 99549
Ptnml(0-2): 271, 22124, 62138, 22801, 282
closes https://github.com/official-stockfish/Stockfish/pull/3885
bench 4572746
2022-01-10 19:35:53 +01:00
