Sebastian Buchwald and Joost VandeVondele
7a3483fa9e
Remove superfluous cast
...
closes https://github.com/official-stockfish/Stockfish/pull/6277
No functional change
2025-08-30 15:14:51 +02:00
Torsten Hellwig and Joost VandeVondele
6a6dadb5a6
Remove buggy and unused function
...
The function does not fulfill its purpose and is not used anywhere.
See https://discord.com/channels/435943710472011776/1101022188313772083/1409801409855094874
closes https://github.com/official-stockfish/Stockfish/pull/6275
no functional change
2025-08-30 15:13:40 +02:00
Shawn Xu and Joost VandeVondele
3f18352396
Further Simplify Stalemate Detection
...
Passed Non-regression STC:
LLR: 2.98 (-2.94,2.94) <-1.75,0.25>
Total: 191520 W: 49633 L: 49582 D: 92305
Ptnml(0-2): 557, 20676, 53260, 20693, 574
https://tests.stockfishchess.org/tests/view/68ab570075da51a345a5abe1
Passed Non-regression LTC:
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 212934 W: 54643 L: 54618 D: 103673
Ptnml(0-2): 117, 22417, 61364, 22462, 107
https://tests.stockfishchess.org/tests/view/68ab84e975da51a345a5ac6b
10k Stalemate:
Elo: 0.35 ± 1.2 (95%) LOS: 71.6%
Total: 10000 W: 4602 L: 4592 D: 806
Ptnml(0-2): 0, 148, 4694, 158, 0
nElo: 1.99 ± 6.8 (95%) PairsRatio: 1.07
https://tests.stockfishchess.org/tests/view/68abeb8175da51a345a5af82
closes https://github.com/official-stockfish/Stockfish/pull/6268
Bench: 2420973
2025-08-30 15:12:06 +02:00
7d213afd37
Non-functional simplifications
...
closes https://github.com/official-stockfish/Stockfish/pull/6267
No functional change
Co-authored-by: Daniel Monroe <github.com@danielmonroe.net >
2025-08-30 15:09:47 +02:00
Shawn Xu and Joost VandeVondele
a289ee389a
Simplify Capture Futility Pruning
...
Passed Non-regression STC:
LLR: 2.97 (-2.94,2.94) <-1.75,0.25>
Total: 187904 W: 48639 L: 48583 D: 90682
Ptnml(0-2): 560, 22150, 48502, 22154, 586
https://tests.stockfishchess.org/tests/view/68aad56075da51a345a5a9e3
Passed Non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 94302 W: 24246 L: 24101 D: 45955
Ptnml(0-2): 44, 10274, 26371, 10417, 45
https://tests.stockfishchess.org/tests/view/68ab541975da51a345a5aacf
closes https://github.com/official-stockfish/Stockfish/pull/6266
Bench: 2376717
2025-08-30 15:09:00 +02:00
Robert Nurnberg @ elitebook and Joost VandeVondele
222df615c1
revert #6259
...
The recent commit af181d9https://github.com/vondele/matetrack/blob/69f5c5e8627c163a6a8480b869ee09bc44dc44d4/matetrack1000000.csv#L4075-L4076
So this PR proposes to revert it, while adding a comment in the code for future reference.
closes https://github.com/official-stockfish/Stockfish/pull/6269
Bench: 2566711
2025-08-30 15:06:57 +02:00
Nonlinear2 and Joost VandeVondele
75f07da912
Avoid high rule50 count zeroing cutoffs
...
If the depth is low enough, don't TT cut if the rule50 count is high and the TT move is zeroing.
Passed STC:
https://tests.stockfishchess.org/tests/view/68a8fdd8b6fb3300203bcb92
LLR: 3.05 (-2.94,2.94) <0.00,2.00>
Total: 110304 W: 28805 L: 28402 D: 53097
Ptnml(0-2): 275, 11174, 31875, 11529, 299
Passed LTC:
https://tests.stockfishchess.org/tests/view/68aa200f75da51a345a5a809
LLR: 3.00 (-2.94,2.94) <0.50,2.50>
Total: 187956 W: 48489 L: 47928 D: 91539
Ptnml(0-2): 59, 16118, 61075, 16655, 71
closes https://github.com/official-stockfish/Stockfish/pull/6271
bench: 2641840
2025-08-30 15:05:11 +02:00
Akshat Sinha and Joost VandeVondele
69de394439
fix ppc altivec check & loongarch64-lsx typo
...
closes https://github.com/official-stockfish/Stockfish/pull/6276
No functional change
2025-08-30 15:03:09 +02:00
Sebastian Buchwald and Joost VandeVondele
cb7232a818
Use integer type for UCI spin values
...
In particular, parse spin values as integers to avoid rounding errors.
Fixes https://github.com/official-stockfish/Stockfish/issues/6263
closes https://github.com/official-stockfish/Stockfish/pull/6264
No functional change
2025-08-30 15:02:05 +02:00
Shawn Xu and Joost VandeVondele
678d503d8f
Simplify LMR Extensions
...
Passed Non-regression STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 236896 W: 61683 L: 61683 D: 113530
Ptnml(0-2): 730, 28057, 60901, 28003, 757
https://tests.stockfishchess.org/tests/view/68a9c20475da51a345a5a6a0
Passed Non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 73644 W: 18936 L: 18770 D: 35938
Ptnml(0-2): 33, 7951, 20685, 8123, 30
https://tests.stockfishchess.org/tests/view/68aa95c575da51a345a5a88a
closes https://github.com/official-stockfish/Stockfish/pull/6265
Bench: 2693376
2025-08-24 20:10:43 +02:00
Stefan Geschwentner and Joost VandeVondele
39c077f15a
Less reduction for later threads.
...
Give "(thread id mod 8) * 64" less reductions (up to nearly a half ply).
Passed SMP STC:
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 413176 W: 106496 L: 105666 D: 201014
Ptnml(0-2): 504, 46732, 111266, 47602, 484
https://tests.stockfishchess.org/tests/view/68a24aeeb6fb3300203bbdc4
Passed SMP LTC:
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 60420 W: 15622 L: 15268 D: 29530
Ptnml(0-2): 11, 6106, 17632, 6440, 21
https://tests.stockfishchess.org/tests/view/68a2c2ffb6fb3300203bc516
closes https://github.com/official-stockfish/Stockfish/pull/6249
No functional change
2025-08-24 20:07:50 +02:00
FauziAkram and Joost VandeVondele
c99eb8ef32
Remove cap from a bonusScale formula
...
Passed STC:
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 127264 W: 33159 L: 33042 D: 61063
Ptnml(0-2): 336, 14509, 33866, 14544, 377
https://tests.stockfishchess.org/tests/view/68a63fccb6fb3300203bc818
Passed LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 469512 W: 120094 L: 120331 D: 229087
Ptnml(0-2): 238, 51317, 131885, 51076, 240
https://tests.stockfishchess.org/tests/view/68a8d867b6fb3300203bcab5
closes https://github.com/official-stockfish/Stockfish/pull/6260
Bench: 2433974
2025-08-24 20:01:01 +02:00
Michael Chaly and Joost VandeVondele
af181d9fe1
Small simplification in probCut movepicker
...
Remove no longer required condition for tt moves. The idea is that if tt the value is
greater than probCut beta try tt move that is a capture anyway - even if it
doesn't pass SEE check. This idea in various implementations passed some STCs
and was looking decent at LTCs as a gainer.
Passed STC:
https://tests.stockfishchess.org/tests/view/68aa1ee075da51a345a5a805
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 136160 W: 35189 L: 35079 D: 65892
Ptnml(0-2): 436, 16083, 34891, 16275, 395
Passed LTC:
https://tests.stockfishchess.org/tests/view/68aa91d375da51a345a5a884
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 80022 W: 20652 L: 20492 D: 38878
Ptnml(0-2): 33, 8717, 22357, 8865, 39
closes https://github.com/official-stockfish/Stockfish/pull/6259
Bench: 2307940
2025-08-24 19:58:49 +02:00
Shawn Xu and Joost VandeVondele
e2fdf6f005
Simplify separate malus formulas
...
Passed Non-regression STC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 16352 W: 4336 L: 4090 D: 7926
Ptnml(0-2): 54, 1832, 4157, 2080, 53
https://tests.stockfishchess.org/tests/view/68a808f0b6fb3300203bca08
Passed Non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 94014 W: 24129 L: 23986 D: 45899
Ptnml(0-2): 47, 9917, 26934, 10064, 45
https://tests.stockfishchess.org/tests/view/68a8f45cb6fb3300203bcb5e
closes https://github.com/official-stockfish/Stockfish/pull/6256
Bench: 2483704
2025-08-24 19:55:35 +02:00
Shawn Xu and Joost VandeVondele
901ad7e7ee
Simplify quiet move streak
...
Passed Non-regression STC:
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 46272 W: 12076 L: 11866 D: 22330
Ptnml(0-2): 140, 5407, 11860, 5561, 168
https://tests.stockfishchess.org/tests/view/68a9c26575da51a345a5a6a2
Passed Non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 140442 W: 35984 L: 35886 D: 68572
Ptnml(0-2): 72, 15333, 39305, 15447, 64
https://tests.stockfishchess.org/tests/view/68aa245e75da51a345a5a80d
closes https://github.com/official-stockfish/Stockfish/pull/6258
Bench: 2931171
2025-08-24 19:52:42 +02:00
Shawn Xu and Joost VandeVondele
85f87649bf
Simplify stalemate detection
...
Passed Non-regression STC:
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 107392 W: 27959 L: 27818 D: 51615
Ptnml(0-2): 317, 12094, 28735, 12231, 319
https://tests.stockfishchess.org/tests/view/68a65d8ab6fb3300203bc825
Passed Non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 94014 W: 24129 L: 23986 D: 45899
Ptnml(0-2): 47, 9917, 26934, 10064, 45
https://tests.stockfishchess.org/tests/view/68a8f45cb6fb3300203bcb5e
Passed Stalemate 10k:
Elo: 2.22 ± 1.3 (95%) LOS: 100.0%
Total: 10000 W: 4626 L: 4562 D: 812
Ptnml(0-2): 1, 137, 4659, 203, 0
nElo: 12.00 ± 6.8 (95%) PairsRatio: 1.47
https://tests.stockfishchess.org/tests/view/68a65d8ab6fb3300203bc825
Supersedes #6114
Closes #6232
closes https://github.com/official-stockfish/Stockfish/pull/6255
Bench: 2473929
2025-08-24 19:50:51 +02:00
Daniel Monroe and Joost VandeVondele
7fa7a36dc6
Remove upper bound in see margin
...
Passed simplification STC
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 99840 W: 25965 L: 25815 D: 48060
Ptnml(0-2): 326, 11708, 25688, 11886, 312
https://tests.stockfishchess.org/tests/view/68a24504b6fb3300203bbdae
Passed simplification LTC
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 248388 W: 63544 L: 63556 D: 121288
Ptnml(0-2): 125, 27132, 69709, 27086, 142
https://tests.stockfishchess.org/tests/view/68a24f3bb6fb3300203bbdee
closes https://github.com/official-stockfish/Stockfish/pull/6250
Bench: 2432765
2025-08-24 19:47:20 +02:00
Daniel Samek and Joost VandeVondele
2659351ce7
Remove depth reduction in the full-depth search
...
Passed simplification STC:
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 217184 W: 56218 L: 56195 D: 104771
Ptnml(0-2): 627, 25673, 55985, 25664, 643
https://tests.stockfishchess.org/tests/view/68a21e0eb6fb3300203bbcf3
Passed simplification LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 30474 W: 7923 L: 7713 D: 14838
Ptnml(0-2): 20, 3205, 8569, 3431, 12
https://tests.stockfishchess.org/tests/view/68a2adacb6fb3300203bc3f9
closes https://github.com/official-stockfish/Stockfish/pull/6246
bench 2626263
2025-08-24 19:45:23 +02:00
Daniel Monroe and Joost VandeVondele
57d76bd459
Simplify depth condition in prior reduction
...
Passed simplification STC
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 172864 W: 45085 L: 45015 D: 82764
Ptnml(0-2): 516, 20456, 44405, 20552, 503
https://tests.stockfishchess.org/tests/view/68a24791b6fb3300203bbdb6
Passed simplification LTC
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 84738 W: 21733 L: 21578 D: 41427
Ptnml(0-2): 49, 9169, 23780, 9320, 51
https://tests.stockfishchess.org/tests/view/68a2665ab6fb3300203bc269
closes https://github.com/official-stockfish/Stockfish/pull/6244
Bench: 2131292
2025-08-24 19:43:48 +02:00
Disservin and Joost VandeVondele
47d60a50b6
CI: fix typo in flag
...
closes https://github.com/official-stockfish/Stockfish/pull/6247
No functional change
2025-08-24 19:40:40 +02:00
FauziAkram and Joost VandeVondele
176ef577e2
Set back static constexpr
...
closes https://github.com/official-stockfish/Stockfish/pull/6243
No functional change
2025-08-24 19:39:49 +02:00
Myself and Joost VandeVondele
20bc19558e
Speedup_threat_by_lesser
...
This patch could have been considered a non-functional speedup, but changing
the ranking of illegal moves.
Passed STC:
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 131040 W: 34247 L: 33792 D: 63001
Ptnml(0-2): 407, 15281, 33675, 15764, 393
https://tests.stockfishchess.org/tests/live_elo/68a9a75b75da51a345a5a66d
Passed LTC:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 280146 W: 72055 L: 71242 D: 136849
Ptnml(0-2): 153, 30252, 78438, 31089, 141
https://tests.stockfishchess.org/tests/view/68a9f58475da51a345a5a6e0
closes https://github.com/official-stockfish/Stockfish/pull/6261
Bench: 2321931
2025-08-24 19:37:58 +02:00
Stefan Geschwentner and Joost VandeVondele
d11f49b790
Remove log depth reduction terms.
...
Motivated by the elo loss of last VVLTC regression test i remove the new log
depth reductions (tuned at STC) to regain strength at VVLTC. The constant terms
are adjusted based on the old values and the changes from the last added VVLTC
tuning.
Passed VVLTC with STC bound:
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 53802 W: 14030 L: 13740 D: 26032
Ptnml(0-2): 5, 4924, 16754, 5212, 6
https://tests.stockfishchess.org/tests/view/68a9a9f575da51a345a5a675
Passed VVLTC with LTC bound:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 53658 W: 14022 L: 13699 D: 25937
Ptnml(0-2): 3, 4894, 16712, 5217, 3
https://tests.stockfishchess.org/tests/view/68a8d2b2b6fb3300203bca77
closes https://github.com/official-stockfish/Stockfish/pull/6257
Bench: 2566780
2025-08-24 19:30:31 +02:00
FauziAkram and Joost VandeVondele
7fe46b5a70
VVLTC tweak
...
Passed VVLTC with STC bounds:
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 60796 W: 15908 L: 15609 D: 29279
Ptnml(0-2): 6, 5598, 18889, 5901, 4
https://tests.stockfishchess.org/tests/view/68a1fbfeb6fb3300203bbc5c
Passed VVLTC with LTC bounds:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 24914 W: 6528 L: 6256 D: 12130
Ptnml(0-2): 4, 2263, 7648, 2541, 1
https://tests.stockfishchess.org/tests/view/68a211aeb6fb3300203bbca7
closes https://github.com/official-stockfish/Stockfish/pull/6241
Bench: 2130122
2025-08-17 22:46:04 +02:00
Stefan Geschwentner and Joost VandeVondele
8ecfc3c89d
Bigger thread dependent initial window.
...
Increase the initial delta of the aspiration window by "thread id mod 8".
Passed SMP STC:
LLR: 2.96 (-2.94,2.94) <0.00,2.00>
Total: 106176 W: 27470 L: 27069 D: 51637
Ptnml(0-2): 121, 12032, 28386, 12423, 126
https://tests.stockfishchess.org/tests/view/68a178fab6fb3300203bbaec
Passed SMP LTC:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 133076 W: 34272 L: 33772 D: 65032
Ptnml(0-2): 38, 13709, 38537, 14223, 31
https://tests.stockfishchess.org/tests/view/68a1b5d2b6fb3300203bbb71
closes https://github.com/official-stockfish/Stockfish/pull/6239
No functional change
2025-08-17 22:39:49 +02:00
87 and Joost VandeVondele
2176c9387e
Add performance warning comment for vpcompressw
...
closes https://github.com/official-stockfish/Stockfish/pull/6237
No functional change
2025-08-17 22:38:09 +02:00
Stefan Geschwentner and Joost VandeVondele
c56bd10cb5
Fix undefined behavior in stalemate trap detection.
...
An important part of it is a function which detects if we can move a king or
pawn. If this function called before quiet move generation phase the end of the
checked move list is undefined (Thanks to AliceRoselia pointing out we have
some problem because of wrong bench in a test).
This problem exists also in master but is really rarely triggered (thanks to
vondele which found one) but it seen significant more often if the capture
order score is increased.
This fix now simply assumes in this case (and other similiar cases) that a king
or pawn can move without checking any moves.
Passed non-regression STC (with default book):
LLR: 3.03 (-2.94,2.94) <-1.75,0.25>
Total: 203008 W: 52465 L: 52424 D: 98119
Ptnml(0-2): 498, 20293, 59893, 20310, 510
https://tests.stockfishchess.org/tests/view/68a06ec5fd8719b088c8dc1a
Passed non-regression STC (with stalemates book):
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 31616 W: 14418 L: 14366 D: 2832
Ptnml(0-2): 1, 189, 15375, 243, 0
https://tests.stockfishchess.org/tests/view/68a07538fd8719b088c8dc1f
closes https://github.com/official-stockfish/Stockfish/pull/6235
Bench: 2996176
2025-08-17 22:35:03 +02:00
Joost VandeVondele
4b6b13ce5a
Update sde action to 2.4, switch to 9.33.0
...
older version no longer downloadable.
closes https://github.com/official-stockfish/Stockfish/pull/6240
No functional change
2025-08-17 22:32:03 +02:00
Daniel Monroe and Joost VandeVondele
169737a9eb
Simplify dual bonuses
...
Merge dual capture/quiet bonuses into one
Passed simplification STC
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 223200 W: 57868 L: 57854 D: 107478
Ptnml(0-2): 689, 26441, 57296, 26515, 659
https://tests.stockfishchess.org/tests/view/6898d28e0049e8ccef9d6384
Passed simplification LTC
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 147270 W: 37750 L: 37659 D: 71861
Ptnml(0-2): 84, 15869, 41633, 15970, 79
https://tests.stockfishchess.org/tests/view/68990fe30049e8ccef9d643c
closes https://github.com/official-stockfish/Stockfish/pull/6226
Bench: 2996176
2025-08-16 12:12:07 +02:00
Daniel Monroe and Joost VandeVondele
c9c002450a
Simplify depth term in reductions
...
Passed simplification STC
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 317344 W: 82352 L: 82442 D: 152550
Ptnml(0-2): 999, 37395, 81907, 37439, 932
https://tests.stockfishchess.org/tests/live_elo/68976798f8a258623dda6c46
Passed simplification LTC
LLR: 2.97 (-2.94,2.94) <-1.75,0.25>
Total: 291708 W: 74733 L: 74787 D: 142188
Ptnml(0-2): 159, 31813, 81956, 31775, 151
https://tests.stockfishchess.org/tests/live_elo/689791a5f8a258623dda6d03
closes https://github.com/official-stockfish/Stockfish/pull/6225
Bench: 2436991
2025-08-16 12:06:00 +02:00
Kevin Lu and Joost VandeVondele
0db4a1bee9
Remove completedDepth condition for SE
...
Just removing the term
Passed STC:
LLR: 3.27 (-2.94,2.94) <-1.75,0.25>
Total: 179840 W: 47211 L: 47126 D: 85503
Ptnml(0-2): 567, 17929, 52879, 17942, 603
https://tests.stockfishchess.org/tests/view/688bdd88502b34dd5e7111ea
Passed LTC:
LLR: 3.26 (-2.94,2.94) <-1.75,0.25>
Total: 150708 W: 38738 L: 38637 D: 73333
Ptnml(0-2): 79, 12922, 49262, 13001, 90
https://tests.stockfishchess.org/tests/view/688ce857f17748b4d23c8026
Passed VLTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 288312 W: 74104 L: 74152 D: 140056
Ptnml(0-2): 44, 26732, 90657, 26674, 49
https://tests.stockfishchess.org/tests/view/688ec4f57d68fe4f7f130ee3
closes https://github.com/official-stockfish/Stockfish/pull/6221
functional at higher depths
Bench: 3002300
2025-08-16 12:01:19 +02:00
FauziAkram and Joost VandeVondele
d864148595
Simplify beta formula
...
Passed STC:
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 152384 W: 39907 L: 39814 D: 72663
Ptnml(0-2): 557, 17958, 39053, 18083, 541
https://tests.stockfishchess.org/tests/view/6890b66692fcad741b804a10
Passed LTC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 98688 W: 25411 L: 25270 D: 48007
Ptnml(0-2): 45, 10692, 27743, 10805, 59
https://tests.stockfishchess.org/tests/view/6896019c618946ab878347b0
closes: https://github.com/official-stockfish/Stockfish/pull/6220
bench: 3002300
2025-08-16 11:57:44 +02:00
Stefan Geschwentner and Joost VandeVondele
2e91a86354
Add log depth as term to reduction factors.
...
Replace most reduction factors with a linear term of the form X + Y * msb(depth) (using msb(depth) as simple and fast approximation for log(depth))
and tune the weights with following SPSA test: https://tests.stockfishchess.org/tests/view/689903860049e8ccef9d6415 .
Here the tuned values of X[8] and Y[8] were ignored because a simple test with this parameters alone failed badly (https://tests.stockfishchess.org/tests/view/68992b350049e8ccef9d6482 ).
Passed STC:
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 32448 W: 8651 L: 8342 D: 15455
Ptnml(0-2): 81, 3695, 8408, 3914, 126
https://tests.stockfishchess.org/tests/view/6899489b0049e8ccef9d64ad
Passed LTC:
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 73854 W: 19042 L: 18649 D: 36163
Ptnml(0-2): 37, 7908, 20659, 8271, 52
https://tests.stockfishchess.org/tests/view/689abbe7fd8719b088c8d514
closes https://github.com/official-stockfish/Stockfish/pull/6229
Bench: 3151102
2025-08-16 11:51:39 +02:00
mstembera and Joost VandeVondele
0383670cd5
Avoid using _mm512_storeu_epi16()
...
gcc 9 & 10 do not provide this function, instead use the generic _mm512_storeu_si512
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95483
https://tests.stockfishchess.org/actions?max_actions=1&action=&user=&text=&before=1755266300.455175&run_id=
closes https://github.com/official-stockfish/Stockfish/pull/6231
No functional change
2025-08-16 11:46:39 +02:00
Jost Triller and Joost VandeVondele
7a07ac0e76
Adjust probcut on staticEval
...
Reducing probcut depth more when staticEval is very good and less if staticEval is not so good compared to beta
STC: https://tests.stockfishchess.org/tests/view/68926bf6690844f940fa1350
LLR: 2.98 (-2.94,2.94) <0.00,2.00>
Total: 174400 W: 45698 L: 45174 D: 83528
Ptnml(0-2): 622, 20356, 44672, 20976, 574
LTC: https://tests.stockfishchess.org/tests/view/689651b4f8a258623dda6531
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 56010 W: 14547 L: 14191 D: 27272
Ptnml(0-2): 31, 5929, 15738, 6267, 40
This patch was generated using qwen3-235b-a22b-thinking-2507:
Prompt: https://rentry.co/bm6vriai
Thinking: https://rentry.co/34km4zf8
Final respone: https://rentry.co/rauotrvr
closes https://github.com/official-stockfish/Stockfish/pull/6219
Bench: 3629755
2025-08-09 09:08:38 +02:00
FauziAkram and Joost VandeVondele
ade8917447
Remove outdated comment
...
Remove the Elo worth, as they are now completely outdated, making them irrelevant and potentially misleading
Continuation of #5810 as these comments in "history.h" were missed.
closes https://github.com/official-stockfish/Stockfish/pull/6216
No functional change
2025-08-09 09:04:33 +02:00
mstembera and Joost VandeVondele
5464f7b114
Remove an instruction from find_nnz()
...
closes https://github.com/official-stockfish/Stockfish/pull/6212
No functional change
2025-08-09 08:54:47 +02:00
Niklas Fiekas and Joost VandeVondele
125a0cfe7b
Build x86-64-avx512icl in CI
...
closes https://github.com/official-stockfish/Stockfish/pull/6217
No functional change
2025-08-09 08:51:45 +02:00
Stockfisher69 and Joost VandeVondele
303fe9a164
Simplification: Futility pruning for captures
...
tested in final form as simplication
passed LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 113682 W: 29199 L: 29074 D: 55409
Ptnml(0-2): 68, 12359, 31859, 12490, 65
https://tests.stockfishchess.org/tests/view/688e85a17d68fe4f7f130e24
earlier test, equivalent:
passed STC:
LLR: 2.96 (-2.94,2.94) <0.00,2.00>
Total: 120224 W: 31621 L: 31176 D: 57427
Ptnml(0-2): 415, 14167, 30567, 14484, 479
https://tests.stockfishchess.org/tests/view/68888bdd7b562f5f7b732643
closes https://github.com/official-stockfish/Stockfish/pull/6209
Bench: 2661621
2025-08-09 08:49:12 +02:00
KazApps and Joost VandeVondele
b177b7394a
Separate bonus/malus parameters for quiet and capture moves
...
Parameters were tuned on 60k STC games.
Passed STC
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 16928 W: 4570 L: 4277 D: 8081
Ptnml(0-2): 57, 1905, 4270, 2152, 80
https://tests.stockfishchess.org/tests/view/688b4486502b34dd5e711122
Passed LTC
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 43602 W: 11373 L: 11041 D: 21188
Ptnml(0-2): 23, 4657, 12116, 4975, 30
https://tests.stockfishchess.org/tests/view/688c0eb5502b34dd5e71124b
Passed non-regression VLTC
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 181016 W: 46335 L: 46281 D: 88400
Ptnml(0-2): 33, 18177, 54034, 18231, 33
https://tests.stockfishchess.org/tests/view/688e0a77f17748b4d23c822b
closes https://github.com/official-stockfish/Stockfish/pull/6200
bench: 3435529
2025-08-09 08:43:49 +02:00
rn5f107s2 and Joost VandeVondele
94175524b1
Only set ep square if ep capture is possible
...
for positions such as:
position fen rr6/2q2p1k/2P1b1pp/bB2P1n1/R2B2PN/p4P1P/P1Q4K/1R6 b - - 2 38 moves f7f5
position fen 8/p2r1pK1/6p1/1kp1P1P1/2p5/2P5/8/4R3 b - - 0 43 moves f7f5
position fen 4k3/4p3/2b3b1/3P1P2/4K3/8/8/8 b - - moves e7e5
ep is not possible for various reasons. Do not set the ep square and the do not change the zobrist key, as if ep were possible.
This fixes 3-fold detection, which could in rare cases be observed as a warning generated by fastchess for PVs that continued beyond an actual 3-fold.
Also fixes wrong evals for certain moves e.g. a2a1 for
position fen 4k3/1b2p2b/8/3P1P2/4K3/8/8/r7 b - - 0 1 moves e7e5 e4e3 a1a2 e3e4 a2a1 e4f3 a1a2 f3e4
fixes https://github.com/official-stockfish/Stockfish/issues/6138
originally written and tested by rn5f107s2, with small buglet as
https://tests.stockfishchess.org/tests/view/685af90843ce022d15794400
failed STC
LLR: -2.93 (-2.94,2.94) <-1.75,0.25>
Total: 130688 W: 33986 L: 34362 D: 62340
Ptnml(0-2): 414, 13292, 38302, 12928, 408
https://tests.stockfishchess.org/tests/view/688bcb35502b34dd5e7111c9
passed LTC
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 99018 W: 25402 L: 25273 D: 48343
Ptnml(0-2): 54, 9097, 31089, 9204, 65
https://tests.stockfishchess.org/tests/view/688c613c502b34dd5e7112d3
https://github.com/official-stockfish/Stockfish/pull/6211
Bench: 2946135
Co-authored-by: Joost VandeVondele <Joost.VandeVondele@gmail.com >
2025-08-04 15:16:21 +02:00
Jost Triller and Joost VandeVondele
377a3a5269
Depth dependent reduction threshold when full-depth re-search
...
STC: https://tests.stockfishchess.org/tests/view/68894d577b562f5f7b73273b
LLR: 2.98 (-2.94,2.94) <0.00,2.00>
Total: 155072 W: 40651 L: 40150 D: 74271
Ptnml(0-2): 609, 18271, 39292, 18738, 626
LTC: https://tests.stockfishchess.org/tests/view/688c2705502b34dd5e71127a
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 321012 W: 82891 L: 81995 D: 156126
Ptnml(0-2): 227, 34421, 90285, 35375, 198
This commit was generated using qwen3-235b-a22b-thinking-2507:
Prompt: https://rentry.co/iqtaoht7
Reasoning/thinking: https://rentry.co/wm6t9hye
closes https://github.com/official-stockfish/Stockfish/pull/6210
Bench: 2983938
2025-08-04 15:12:55 +02:00
Shawn Xu and Joost VandeVondele
14a2e50a3d
Simplify key after
...
Passed Non-regression STC:
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 534016 W: 139438 L: 139771 D: 254807
Ptnml(0-2): 2098, 63469, 136136, 63278, 2027
https://tests.stockfishchess.org/tests/view/688ac64d502b34dd5e7110a4
Passed Non-regression LTC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 43980 W: 11346 L: 11149 D: 21485
Ptnml(0-2): 31, 4689, 12353, 4886, 31
https://tests.stockfishchess.org/tests/view/688ea8a47d68fe4f7f130eb3
closes https://github.com/official-stockfish/Stockfish/pull/6207
Bench: 2884232
2025-08-04 15:07:37 +02:00
Michael Chaly and Joost VandeVondele
5d1505d8c7
Reintroduce reduction term in LMR for cutnodes
...
This term increases reduction for cutnodes without tt move, term was simplified away recently.
Passed STC:
https://tests.stockfishchess.org/tests/view/688882007b562f5f7b73262f
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 187616 W: 49367 L: 48824 D: 89425
Ptnml(0-2): 710, 21898, 48034, 22471, 695
Passed LTC:
https://tests.stockfishchess.org/tests/view/688c71f4502b34dd5e71139a
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 140280 W: 36280 L: 35750 D: 68250
Ptnml(0-2): 79, 15175, 39121, 15667, 98
closes https://github.com/official-stockfish/Stockfish/pull/6206
Bench: 2996732
2025-08-04 14:58:59 +02:00
FauziAkram and Joost VandeVondele
8e733d68fd
Refactor: Simplify pawn structure indexing
...
Refactoring the mechanism for calculating pawn structure hash indices and make it consistent with the rest.
closes https://github.com/official-stockfish/Stockfish/pull/6205
No functional change
2025-08-04 14:56:03 +02:00
Joost VandeVondele
a6e34f128f
Fix icx profile-build
...
fixes the issue pointed out in https://github.com/official-stockfish/Stockfish/pull/6202
closes https://github.com/official-stockfish/Stockfish/pull/6203
No functional change
2025-08-04 14:53:49 +02:00
FauziAkram and Joost VandeVondele
a37b38bdf0
Add "d < newDepth" condition for doDeeperSearch
...
Add "d < newDepth" condition for doDeeperSearch
Passed STC:
LLR: 2.97 (-2.94,2.94) <0.00,2.00>
Total: 66144 W: 17512 L: 17148 D: 31484
Ptnml(0-2): 220, 7726, 16833, 8056, 237
https://tests.stockfishchess.org/tests/view/6887cce67b562f5f7b731a79
Passed LTC:
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 411240 W: 106103 L: 105023 D: 200114
Ptnml(0-2): 256, 44249, 115566, 45257, 292
https://tests.stockfishchess.org/tests/view/6887ec527b562f5f7b731c37
closes https://github.com/official-stockfish/Stockfish/pull/6204
Bench: 2917036
2025-08-02 16:25:31 +02:00
FauziAkram and Joost VandeVondele
62b958f517
Remove code that is not used anywhere
...
closes https://github.com/official-stockfish/Stockfish/pull/6201
No functional change
2025-08-02 16:21:41 +02:00
Daniel Monroe and Joost VandeVondele
cd52859bd5
Simplify improving term
...
Set improving whenever ss->staticEval >= beta
Passed simplification STC
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 38016 W: 10122 L: 9900 D: 17994
Ptnml(0-2): 143, 4388, 9747, 4564, 166
https://tests.stockfishchess.org/tests/view/688803917b562f5f7b7322eb
Passed simplification LTC
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 21648 W: 5594 L: 5375 D: 10679
Ptnml(0-2): 12, 2241, 6096, 2466, 9
https://tests.stockfishchess.org/tests/view/688820397b562f5f7b73235d
closes https://github.com/official-stockfish/Stockfish/pull/6198
Bench: 3576884
2025-08-02 16:18:46 +02:00
CSTENTOR and Joost VandeVondele
57b32f3e60
Make Resetting the Aspiration Window after FailLow more aggressive
...
Sets beta=(3alpha+beta)/4 when failLow. Before it was beta=(alpha+beta)/2, even
though in theory we should be getting an upper bound from a failLow, we can’t
trust the score that caused the failLow. Therefore beta=alpha doesn’t work. I
made the buffer between the new beta to the bestValue that caused the failLow
smaller.
passed STC:
https://tests.stockfishchess.org/tests/view/688674947b562f5f7b7315b5
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 119616 W: 31253 L: 30818 D: 57545
Ptnml(0-2): 313, 14028, 30724, 14397, 346
passed LTC:
https://tests.stockfishchess.org/tests/view/6887e0ad7b562f5f7b731afc
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 96978 W: 24905 L: 24466 D: 47607
Ptnml(0-2): 59, 10376, 27183, 10809, 62
closes https://github.com/official-stockfish/Stockfish/pull/6197
bench: 3085519
2025-08-02 16:12:12 +02:00
