Guenther Demetz and Joost VandeVondele
b6082ba750
Simplify search functions according DRY principle
...
Passed STC non-regression bounds
https://tests.stockfishchess.org/tests/view/6870db4bfa93cf16d3bb286a
LLR: 3.00 (-2.94,2.94) <-1.75,0.25>
Total: 182016 W: 46735 L: 46673 D: 88608
Ptnml(0-2): 368, 19895, 50465, 19867, 413
closes https://github.com/official-stockfish/Stockfish/pull/6161
no functional change
2025-07-28 19:35:28 +02:00
Muzhen Gaming and Joost VandeVondele
90c83c381f
VVLTC Search Tune
...
alues were tuned with 125k VVLTC games.
Passed VVLTC 1st sprt:
https://tests.stockfishchess.org/tests/view/68865feb7b562f5f7b731341
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 39640 W: 10380 L: 10109 D: 19151
Ptnml(0-2): 5, 3556, 12424, 3833, 2
Passed VVLTC 2nd sprt:
https://tests.stockfishchess.org/tests/view/68864dfa7b562f5f7b7312ee
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 25972 W: 6807 L: 6537 D: 12628
Ptnml(0-2): 0, 2294, 8132, 2556, 4
closes https://github.com/official-stockfish/Stockfish/pull/6188
Bench: 3143696
2025-07-28 19:33:00 +02:00
aronpetkovski and Joost VandeVondele
a516b517d3
Simplify eval >= beta condition from NMP
...
It seems that now only checking if static eval is above beta by some margin is all that's necessary.
Passed Non-Regression STC
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 227264 W: 58430 L: 58421 D: 110413
Ptnml(0-2): 532, 26559, 59454, 26542, 545
https://tests.stockfishchess.org/tests/view/68763a77432ca24f6388c766
Passed Non-Regression LTC
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 72048 W: 18622 L: 18455 D: 34971
Ptnml(0-2): 26, 7775, 20272, 7908, 43
https://tests.stockfishchess.org/tests/view/687c9f2b6e17e7fa3939b0c5
closes https://github.com/official-stockfish/Stockfish/pull/6175
Bench: 2759840
2025-07-24 10:38:13 +02:00
Daniel Monroe and Joost VandeVondele
92514fd3a2
Simplify away a term in see pruning
...
This change only sets the margin to 0 when depth <= 2 and margin <= 42 which
never has a difference, thus non-functional
Passed non-regression STC
LLR: 3.51 (-2.94,2.94) <-1.75,0.25>
Total: 306976 W: 78935 L: 78961 D: 149080
Ptnml(0-2): 630, 34097, 84067, 34057, 637
https://tests.stockfishchess.org/tests/view/68708015fa93cf16d3bb2782
closes https://github.com/official-stockfish/Stockfish/pull/6170
No functional change
2025-07-24 10:32:41 +02:00
FauziAkram and Joost VandeVondele
bdc393d3a2
Correct comment
...
closes https://github.com/official-stockfish/Stockfish/pull/6159
No functional change
2025-07-24 10:26:15 +02:00
Daniel Samek and Joost VandeVondele
2c9a1871ae
Add offsets to history updates.
...
All parameters were tuned on 60k STC games (https://tests.stockfishchess.org/tests/view/6867ef49fe0f2fe354c0c735 ).
Passed STC:
LLR: 2.98 (-2.94,2.94) <0.00,2.00>
Total: 60576 W: 15794 L: 15444 D: 29338
Ptnml(0-2): 141, 7003, 15642, 7369, 133
https://tests.stockfishchess.org/tests/view/686d5af11451bd6fb830772a
Passed LTC:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 58722 W: 15159 L: 14799 D: 28764
Ptnml(0-2): 19, 6259, 16455, 6599, 29
https://tests.stockfishchess.org/tests/view/686f9fd51451bd6fb83081c9
closes https://github.com/official-stockfish/Stockfish/pull/6158
bench: 2706299
2025-07-24 10:24:08 +02:00
FauziAkram and Joost VandeVondele
793110ca19
Remove !ttData.move condition from cutNode reduction
...
Passed STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 118080 W: 30427 L: 30298 D: 57355
Ptnml(0-2): 290, 13880, 30561, 14029, 280
https://tests.stockfishchess.org/tests/view/6853f9bc038630d25f468670
Passed LTC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 232272 W: 59187 L: 59182 D: 113903
Ptnml(0-2): 111, 25430, 65014, 25505, 76
https://tests.stockfishchess.org/tests/view/68585c40a596a06817bb922e
closes https://github.com/official-stockfish/Stockfish/pull/6157
bench: 2227361
2025-07-24 10:19:10 +02:00
Shawn Xu and Joost VandeVondele
e2aa125570
Consistent syntax for class members
...
Currently, search.cpp uses three different syntax when accessing class member variables
* thisThread object references. This was a remnant from when pos.this_thread() was necessary for thread-local variable access
* this object references
* implicit member variable access
This PR aims to deprecate thisThread and standardize this syntax to implicit variable access, which is consistent with the rest of SF's codebase.
closes https://github.com/official-stockfish/Stockfish/pull/6154
no functional change
2025-07-24 10:13:24 +02:00
Daniel Monroe and Joost VandeVondele
c13f883dc4
simplify away TT history term
...
Passed simplification STC
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 163168 W: 42136 L: 42055 D: 78977
Ptnml(0-2): 410, 19224, 42212, 19351, 387
https://tests.stockfishchess.org/tests/view/684e16ee703522d4f129c9e9
Passed simplification LTC
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 303144 W: 77580 L: 77647 D: 147917
Ptnml(0-2): 150, 33110, 85134, 33013, 165
https://tests.stockfishchess.org/tests/view/6852ff97703522d4f129d5f7
closes https://github.com/official-stockfish/Stockfish/pull/6152
bench: 2294774
2025-07-24 09:59:00 +02:00
Daniel Monroe and Joost VandeVondele
a43f12ef08
Simplify away constants in statscore
...
Passed simplification STC
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 317280 W: 81589 L: 81678 D: 154013
Ptnml(0-2): 799, 37651, 81847, 37526, 817
https://tests.stockfishchess.org/tests/view/684e197a703522d4f129c9f0
Passed simplification LTC
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 174816 W: 44656 L: 44593 D: 85567
Ptnml(0-2): 83, 19064, 49058, 19113, 90
https://tests.stockfishchess.org/tests/view/6858aa54a596a06817bb924f
closes https://github.com/official-stockfish/Stockfish/pull/6150
bench: 2508140
2025-07-24 09:56:36 +02:00
FauziAkram and Joost VandeVondele
6a09a24cd8
Remove depth condition from ttCapture reduction
...
Passed STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 25920 W: 6822 L: 6593 D: 12505
Ptnml(0-2): 54, 2932, 6783, 3113, 78
https://tests.stockfishchess.org/tests/view/6853f9c2038630d25f468672
Passed LTC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 177318 W: 45339 L: 45278 D: 86701
Ptnml(0-2): 85, 19333, 49765, 19388, 88
https://tests.stockfishchess.org/tests/view/6854468a038630d25f4686c0
closes https://github.com/official-stockfish/Stockfish/pull/6149
bench: 2437275
2025-07-24 09:52:35 +02:00
Daniel Monroe and Joost VandeVondele
62f08568cd
Simplify PV term in lmr
...
Passed simplification STC
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 204000 W: 52541 L: 52506 D: 98953
Ptnml(0-2): 561, 24133, 52589, 24144, 573
https://tests.stockfishchess.org/tests/view/684f24ce703522d4f129cab5
Passed simplification LTC
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 156150 W: 39890 L: 39807 D: 76453
Ptnml(0-2): 82, 16882, 44043, 17007, 61
https://tests.stockfishchess.org/tests/view/6855d8bf1d0d9fc6587538f8
closes https://github.com/official-stockfish/Stockfish/pull/6148
bench 2766493
2025-07-24 09:49:43 +02:00
FauziAkram and Disservin
e695b9537e
Remove eval & beta diff from NM reduction
...
Passed STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 43456 W: 11178 L: 10966 D: 21312
Ptnml(0-2): 114, 5078, 11114, 5326, 96
https://tests.stockfishchess.org/tests/view/6849ae13e84567164b5c9de9
Passed LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 63090 W: 16302 L: 16125 D: 30663
Ptnml(0-2): 37, 6837, 17603, 7048, 20
https://tests.stockfishchess.org/tests/view/684ab516e84567164b5ca02f
closes https://github.com/official-stockfish/Stockfish/pull/6134
Bench: 2249459
2025-07-02 18:41:46 +02:00
Robert Nurnberg @ elitebook and Disservin
84e2f3851d
Introduce a constant for ValueList size in search()
...
Having the size of these lists in two separate places likely contributed
to the crashes seen during the recent tuning attempt
https://tests.stockfishchess.org/tests/view/685c413343ce022d15794536 .
Thanks to @MinetaS for spotting this.
closes https://github.com/official-stockfish/Stockfish/pull/6142
No functional change
2025-07-02 18:32:02 +02:00
Daniel Monroe and Disservin
3a0fff96cf
Simplify quiet move streak logic
...
Passed non-regression STC
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 148960 W: 38409 L: 38312 D: 72239
Ptnml(0-2): 372, 17664, 38318, 17747, 379
https://tests.stockfishchess.org/tests/view/684c5773703522d4f129c5f7
Passed non-regression LTC
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 180720 W: 46188 L: 46130 D: 88402
Ptnml(0-2): 84, 19608, 50929, 19644, 95
https://tests.stockfishchess.org/tests/view/68505fa5703522d4f129cbab
closes https://github.com/official-stockfish/Stockfish/pull/6143
Bench: 2055894
2025-07-02 18:31:04 +02:00
Shawn Xu and Disservin
318c948c4d
Remove non-functional low-ply history fill
...
lowPlyHistory is always cleared at the start of `iterative_deepening`, so clearing it here is non-functional.
closes https://github.com/official-stockfish/Stockfish/pull/6144
No functional change
2025-07-02 18:31:04 +02:00
Daniel Monroe and Disservin
a7a56c41f6
Simplify history term in futility pruning
...
Passed simplification STC
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 298816 W: 76814 L: 76881 D: 145121
Ptnml(0-2): 726, 35477, 77057, 35434, 714
https://tests.stockfishchess.org/tests/view/683f440f6ec7634154f9dc7f
Passed simplification LTC
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 237774 W: 60801 L: 60802 D: 116171
Ptnml(0-2): 91, 26088, 66532, 26083, 93
https://tests.stockfishchess.org/tests/view/68441189ffbc71bd236778de
closes https://github.com/official-stockfish/Stockfish/pull/6130
Bench: 2411502
2025-07-02 18:31:04 +02:00
Shawn Xu and Joost VandeVondele
5337edfdb6
remove non-functional else
...
since we break out of the loop in the other branch
closes https://github.com/official-stockfish/Stockfish/pull/6116
no functional change
2025-06-02 22:12:37 +02:00
Daniel Monroe and Joost VandeVondele
9ac756695e
reduce depth by 5 in probcut
...
Passed simplification STC
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 63328 W: 16402 L: 16213 D: 30713
Ptnml(0-2): 174, 7378, 16340, 7629, 143
https://tests.stockfishchess.org/tests/view/6833530e6ec7634154f9be7f
Passed simplification LTC
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 69936 W: 17795 L: 17625 D: 34516
Ptnml(0-2): 29, 7631, 19474, 7809, 25
https://tests.stockfishchess.org/tests/view/68335e386ec7634154f9c266
closes https://github.com/official-stockfish/Stockfish/pull/6120
Bench: 2307268
2025-06-02 22:09:11 +02:00
Daniel Monroe and Joost VandeVondele
254b6d5e85
Simplify corrections in extension margins
...
Passed simplification STC
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 96192 W: 25002 L: 24852 D: 46338
Ptnml(0-2): 242, 10868, 25716, 11038, 232
https://tests.stockfishchess.org/tests/view/683b44cb6ec7634154f9d6ac
Passed simplification LTC
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 83334 W: 21473 L: 21317 D: 40544
Ptnml(0-2): 37, 8877, 23674, 9051, 28
https://tests.stockfishchess.org/tests/view/683b79786ec7634154f9d75a
closes https://github.com/official-stockfish/Stockfish/pull/6117
Bench: 2294814
2025-06-02 22:05:11 +02:00
Shawn Xu and Joost VandeVondele
259bdaaa9f
Remove an unnecessary bound check
...
When failing high, it is always true that `alpha < beta` and `beta <=
bestValue`. Therefore if alpha and bestValue is not in decisive range, it is
guaranteed that beta is not.
closes https://github.com/official-stockfish/Stockfish/pull/6115
no functional change
2025-06-02 21:57:19 +02:00
Daniel Monroe and Joost VandeVondele
3747a19937
Simplify away depth condition in IIR
...
Passed simplification STC
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 359520 W: 92714 L: 92849 D: 173957
Ptnml(0-2): 977, 42640, 92614, 42599, 930
https://tests.stockfishchess.org/tests/view/6833705d6ec7634154f9c302
Passed simplification LTC
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 201756 W: 51544 L: 51507 D: 98705
Ptnml(0-2): 89, 21965, 56728, 22012, 84
https://tests.stockfishchess.org/tests/view/68338e386ec7634154f9c790
Passed simplification VLTC
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 48558 W: 12675 L: 12492 D: 23391
Ptnml(0-2): 9, 4779, 14516, 4970, 5
https://tests.stockfishchess.org/tests/view/6838e0b26ec7634154f9d25b
closes https://github.com/official-stockfish/Stockfish/pull/6112
Bench: 2302583
2025-06-02 21:52:38 +02:00
Daniel Monroe and Joost VandeVondele
70ff5e3163
Simplify away cutoff term in prior countermove bonus
...
Passed simplification STC
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 61120 W: 16010 L: 15819 D: 29291
Ptnml(0-2): 150, 7105, 15869, 7276, 160
https://tests.stockfishchess.org/tests/view/683560226ec7634154f9ce0f
Passed simplification LTC
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 225090 W: 57555 L: 57543 D: 109992
Ptnml(0-2): 104, 24367, 63603, 24355, 116
https://tests.stockfishchess.org/tests/view/6836420c6ec7634154f9cf5c
closes https://github.com/official-stockfish/Stockfish/pull/6111
Bench: 2472910
2025-06-02 21:49:43 +02:00
Daniel Monroe and Joost VandeVondele
ddefd6eb6b
Simplify away check term in statscore
...
Passed simplification STC
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 61696 W: 16031 L: 15841 D: 29824
Ptnml(0-2): 151, 7160, 16046, 7330, 161
https://tests.stockfishchess.org/tests/view/68353fcc6ec7634154f9cdd5
Passed simplification LTC
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 237990 W: 60994 L: 60995 D: 116001
Ptnml(0-2): 95, 25964, 66903, 25913, 120
https://tests.stockfishchess.org/tests/view/683642256ec7634154f9cf5e
closes https://github.com/official-stockfish/Stockfish/pull/6110
Bench: 2521003
2025-06-02 21:47:26 +02:00
Nonlinear2 and Joost VandeVondele
8da3c2155a
Simplify NMP eval in qsearch
...
Passed non-regression STC:
https://tests.stockfishchess.org/tests/view/6834e9436ec7634154f9cd6e
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 24864 W: 6626 L: 6394 D: 11844
Ptnml(0-2): 62, 2806, 6477, 3012, 75
Passed non-regression LTC:
https://tests.stockfishchess.org/tests/view/683598fd6ec7634154f9ce82
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 200148 W: 51461 L: 51424 D: 97263
Ptnml(0-2): 92, 21672, 56503, 21721, 86
closes https://github.com/official-stockfish/Stockfish/pull/6109
Bench: 2316591
2025-06-02 21:44:29 +02:00
Carlos Esparza and Joost VandeVondele
5695486db9
Fix outdated comment
...
closes https://github.com/official-stockfish/Stockfish/pull/6108
No functional change
2025-06-02 21:40:13 +02:00
Shawn Xu and Joost VandeVondele
d0212906bd
Simplify stat eval history adjustment further
...
closes https://github.com/official-stockfish/Stockfish/pull/6106
bench 2074807
2025-06-02 21:37:37 +02:00
Daniel Monroe and Joost VandeVondele
9fd40b9ea8
Simplify tt depth in stat eval history adjustment
...
Passed simplification STC
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 102208 W: 26498 L: 26349 D: 49361
Ptnml(0-2): 284, 12095, 26166, 12306, 253
https://tests.stockfishchess.org/tests/view/683354c76ec7634154f9be88
Passed simplification LTC
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 133422 W: 34050 L: 33945 D: 65427
Ptnml(0-2): 56, 14473, 37559, 14556, 67
https://tests.stockfishchess.org/tests/view/683363626ec7634154f9c298
closes https://github.com/official-stockfish/Stockfish/pull/6099
Bench: 2652411
2025-06-02 21:19:17 +02:00
Daniel Monroe and Joost VandeVondele
dfa176fc7e
Small tt verify simplification
...
Also fix probcut comment
Passed non-regression STC
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 69728 W: 18080 L: 17909 D: 33739
Ptnml(0-2): 161, 7157, 20044, 7354, 148
https://tests.stockfishchess.org/tests/view/68324b116ec7634154f9b478
closes https://github.com/official-stockfish/Stockfish/pull/6094
No functional change
2025-06-02 21:15:56 +02:00
FauziAkram and Joost VandeVondele
73c55e8949
Simplify Double Margin Formula
...
Passed STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 267296 W: 69214 L: 69248 D: 128834
Ptnml(0-2): 760, 31511, 69141, 31475, 761
https://tests.stockfishchess.org/tests/view/682f5d9a6ec7634154f9b01e
Passed LTC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 67872 W: 17460 L: 17289 D: 33123
Ptnml(0-2): 25, 7238, 19243, 7401, 29
https://tests.stockfishchess.org/tests/view/6833074b6ec7634154f9b5ae
Passed VLTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 118000 W: 30337 L: 30222 D: 57441
Ptnml(0-2): 15, 11783, 35289, 11898, 15
https://tests.stockfishchess.org/tests/view/683336c56ec7634154f9ba46
closes https://github.com/official-stockfish/Stockfish/pull/6097
Bench: 2312696
2025-05-25 21:31:12 +02:00
Кирилл Зарипов and Joost VandeVondele
bebffc5622
Adjust futility pruning thresholds using history
...
Passed STC:
https://tests.stockfishchess.org/tests/view/6833095a6ec7634154f9b5b3
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 56896 W: 14946 L: 14604 D: 27346
Ptnml(0-2): 117, 6674, 14561, 6942, 154
Passed LTC:
https://tests.stockfishchess.org/tests/view/6833179d6ec7634154f9b5da
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 200742 W: 51660 L: 51012 D: 98070
Ptnml(0-2): 96, 21520, 56473, 22204, 78
Passed Non-regression SMP STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 29080 W: 7591 L: 7373 D: 14116
Ptnml(0-2): 38, 3178, 7881, 3414, 29
https://tests.stockfishchess.org/tests/view/6833689d6ec7634154f9c2ba
closes https://github.com/official-stockfish/Stockfish/pull/6092
Bench: 2305697
2025-05-25 21:24:09 +02:00
Shawn Xu and Joost VandeVondele
00b1540e01
Always Decrease Reduction on TTMove
...
Passed VVLTC w/ LTC Bounds:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 57792 W: 15005 L: 14676 D: 28111
Ptnml(0-2): 2, 5241, 18082, 5568, 3
https://tests.stockfishchess.org/tests/view/682a0e3c6ec7634154f9a07e
Passed VVLTC w/ STC Bounds:
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 372298 W: 96342 L: 95655 D: 180301
Ptnml(0-2): 37, 34598, 116181, 35307, 26
https://tests.stockfishchess.org/tests/view/682a45b16ec7634154f9a3b3
STC Elo Estimate:
Elo: 0.15 ± 1.4 (95%) LOS: 58.3%
Total: 59612 W: 15414 L: 15388 D: 28810
Ptnml(0-2): 166, 6959, 15527, 6991, 163
nElo: 0.30 ± 2.8 (95%) PairsRatio: 1.00
https://tests.stockfishchess.org/tests/view/68335d276ec7634154f9c25c
closes https://github.com/official-stockfish/Stockfish/pull/6095
bench 2634355
2025-05-25 21:19:59 +02:00
Daniel Samek and Joost VandeVondele
805a2c1672
Simplify FutilityMoveCount
...
Inlined condition, instead of a function.
closes https://github.com/official-stockfish/Stockfish/pull/6096
no functional change
2025-05-25 21:12:27 +02:00
Кирилл Зарипов and Joost VandeVondele
eb27d9420f
Make ProbCut search shallower in cutNode
...
Passed STC:
https://tests.stockfishchess.org/tests/view/6832d2436ec7634154f9b4fc
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 455072 W: 118162 L: 117237 D: 219673
Ptnml(0-2): 1233, 53409, 117362, 54264, 1268
Passed LTC:
https://tests.stockfishchess.org/tests/view/6833323e6ec7634154f9ba17
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 128436 W: 32916 L: 32415 D: 63105
Ptnml(0-2): 50, 13737, 36137, 14250, 44
closes https://github.com/official-stockfish/Stockfish/pull/6093
Bench: 2232447
2025-05-25 21:05:53 +02:00
FauziAkram and Joost VandeVondele
fe7b9b14d2
Implement smoother reduction in time management
...
Implement smoother time reduction in time management by replacing a conditional
assignment with a continuous sigmoid-based function. The updated logic employs
a sigmoid-like function for a more gradual adjustment.
Passed STC:
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 64448 W: 16838 L: 16492 D: 31118
Ptnml(0-2): 145, 7214, 17207, 7466, 192
https://tests.stockfishchess.org/tests/view/6829dc046ec7634154f99fba
Passed LTC:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 407340 W: 104458 L: 103408 D: 199474
Ptnml(0-2): 196, 42281, 117664, 43335, 194
https://tests.stockfishchess.org/tests/view/6829fe1b6ec7634154f9a036
closes https://github.com/official-stockfish/Stockfish/pull/6091
No functional change
2025-05-25 21:03:16 +02:00
b1b5893a8e
Minor code improvements
...
- Remove / add empty lines
- fix the `ttcapture` comment
- remove the `bonus` variable for `ttMoveHistory`
- remove unnecessary parentheses / brackets
- refactor the movepick good quiet stage
- rename `endMoves` to `endCur`, as the previous name suggests that it points to the end of all generated moves, which it does not.
closes https://github.com/official-stockfish/Stockfish/pull/6089
No functional change.
Co-Authored-By: xu-shawn <50402888+xu-shawn@users.noreply.github.com >
2025-05-25 20:59:27 +02:00
pb00067 and Joost VandeVondele
f58d923fe0
Simplify & improve stalemate detection
...
Change is functional because now we verify for stalemate also on captures and when not giving check.
Green STC test on stalemate-book
https://tests.stockfishchess.org/tests/view/682d878f6ec7634154f9ad2f
Elo: 2.29 ± 1.3 (95%) LOS: 100.0%
Total: 10000 W: 4637 L: 4571 D: 792
Ptnml(0-2): 2, 132, 4664, 202, 0
nElo: 12.42 ± 6.8 (95%) PairsRatio: 1.51
Green LTC test on stalemate-book
https://tests.stockfishchess.org/tests/view/682daa2d6ec7634154f9ad67
Elo: 0.80 ± 0.8 (95%) LOS: 96.9%
Total: 10000 W: 4727 L: 4704 D: 569
Ptnml(0-2): 0, 64, 4849, 87, 0
nElo: 6.51 ± 6.8 (95%) PairsRatio: 1.36
Passed non-regression test @ LTC
https://tests.stockfishchess.org/tests/view/682dd10d6ec7634154f9adb3
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 148512 W: 38135 L: 38046 D: 72331
Ptnml(0-2): 55, 15759, 42558, 15810, 74
N.B.: The unique concern I have, is that due changes in future a negative SEE
capture see might be returned in GOOD_CAPTURE stage. In this case the assert in
can_move_king_or_pawn() will trigger since we must guarantee that all moves
(also quiets) are generated in movepicker when calling can_move_king_or_pawn().
closes https://github.com/official-stockfish/Stockfish/pull/6088
bench: 2178135
2025-05-25 20:55:49 +02:00
Daniel Monroe and Joost VandeVondele
4f021cab3b
Simplify allNode term in prior countermove
...
Passed simplification STC
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 53632 W: 14008 L: 13805 D: 25819
Ptnml(0-2): 136, 6253, 13869, 6388, 170
https://tests.stockfishchess.org/tests/view/6828f2b26ec7634154f99b5e
Passed simplification LTC
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 82482 W: 21202 L: 21045 D: 40235
Ptnml(0-2): 37, 8986, 23052, 9115, 51
https://tests.stockfishchess.org/tests/view/6829010a6ec7634154f99db3
closes https://github.com/official-stockfish/Stockfish/pull/6068
Bench: 2302782
2025-05-23 08:51:54 +02:00
Nonlinear2 and Joost VandeVondele
54fb42ddf8
clean up code
...
**Non functional changes:**
in search.cpp:
- an unnecessary pair of parenthesis in the IIR condition has been removed.
- refactored the stalemate trap detection code
in movepick.cpp:
- use the variables `from`, `to`, `piece`, `pieceType` and `capturedPiece` instead of calling the same functions multiple times in `MovePicker::score()`.
- rename `MovePicker::other_piece_types_mobile()`.
**Functional changes:**
- make sure the processed move is always legal in `MovePicker::other_piece_types_mobile()`.
passed non regression STC:
https://tests.stockfishchess.org/tests/view/6829da686ec7634154f99faf
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 95680 W: 24962 L: 24820 D: 45898
Ptnml(0-2): 221, 9622, 28025, 9738, 234
Passed non regression LTC:
https://tests.stockfishchess.org/tests/view/682a102c6ec7634154f9a086
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 117666 W: 30065 L: 29957 D: 57644
Ptnml(0-2): 45, 10173, 38291, 10277, 47
Run of 10k games on the stalemate opening book:
https://tests.stockfishchess.org/tests/view/682b114e6ec7634154f9aa2d
Elo: 0.76 ± 0.9 (95%) LOS: 95.3%
Total: 10000 W: 4637 L: 4615 D: 748
Ptnml(0-2): 0, 75, 4828, 97, 0
nElo: 5.83 ± 6.8 (95%) PairsRatio: 1.29
closes https://github.com/official-stockfish/Stockfish/pull/6080
Bench: 2422771
2025-05-21 07:25:40 +02:00
Daniel Samek and Joost VandeVondele
ccfa651968
Remove full depth search reduction when cutNode
...
Passed STC-simplification bounds:
https://tests.stockfishchess.org/tests/view/6829dd6d6ec7634154f99fd3
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 67872 W: 17629 L: 17443 D: 32800
Ptnml(0-2): 167, 7988, 17451, 8152, 178
Passed LTC-simplification bounds:
https://tests.stockfishchess.org/tests/view/6829f2176ec7634154f9a01c
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 94818 W: 24328 L: 24184 D: 46306
Ptnml(0-2): 52, 10246, 26667, 10394, 50
closes https://github.com/official-stockfish/Stockfish/pull/6074
bench: 2245168
2025-05-19 20:44:14 +02:00
Shawn Xu and Joost VandeVondele
0f102f3692
Simplify Quiet Early Move Penalty
...
Passed STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 185344 W: 47995 L: 47939 D: 89410
Ptnml(0-2): 527, 21898, 47754, 21978, 515
https://tests.stockfishchess.org/tests/view/682a47536ec7634154f9a3bc
Passed LTC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 101706 W: 26050 L: 25912 D: 49744
Ptnml(0-2): 53, 11056, 28499, 11190, 55
https://tests.stockfishchess.org/tests/view/682a61736ec7634154f9a50e
closes https://github.com/official-stockfish/Stockfish/pull/6072
Bench: 2012032
2025-05-19 07:45:28 +02:00
Shawn Xu and Joost VandeVondele
39942db3ff
Simplify In-Check Statscore
...
Passed Non-regression STC:
LLR: 2.98 (-2.94,2.94) <-1.75,0.25>
Total: 129760 W: 33701 L: 33580 D: 62479
Ptnml(0-2): 359, 15248, 33575, 15309, 389
https://tests.stockfishchess.org/tests/view/681a88193629b02d74b17123
Passed Non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 519612 W: 132224 L: 132512 D: 254876
Ptnml(0-2): 246, 56823, 145960, 56527, 250
https://tests.stockfishchess.org/tests/view/681f9ed43629b02d74b177c3
closes https://github.com/official-stockfish/Stockfish/pull/6070
bench: 2046462
2025-05-19 07:39:56 +02:00
Daniel Monroe and Joost VandeVondele
6e9b5af0f0
Check evaluation after ttMove before doing a tt cut
...
Passed STC
LLR: 2.97 (-2.94,2.94) <0.00,2.00>
Total: 239136 W: 62222 L: 61608 D: 115306
Ptnml(0-2): 675, 28046, 61525, 28634, 688
https://tests.stockfishchess.org/tests/view/681053293629b02d74b1668f
Passed LTC
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 448770 W: 115237 L: 114088 D: 219445
Ptnml(0-2): 177, 48128, 126619, 49291, 170
https://tests.stockfishchess.org/tests/view/681902de3629b02d74b16f6d
closes https://github.com/official-stockfish/Stockfish/pull/6069
Bench: 2035432
2025-05-19 07:37:15 +02:00
FauziAkram and Joost VandeVondele
4f76768fcf
Remove a moveCount condition
...
Passed STC:
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 70816 W: 18315 L: 18134 D: 34367
Ptnml(0-2): 210, 8213, 18360, 8436, 189
https://tests.stockfishchess.org/tests/view/68248197a527315e07cccb2d
Passed LTC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 121770 W: 31248 L: 31130 D: 59392
Ptnml(0-2): 61, 13338, 33995, 13404, 87
https://tests.stockfishchess.org/tests/view/68272ff46ec7634154f998ad
closes https://github.com/official-stockfish/Stockfish/pull/6067
bench: 2319161
2025-05-19 07:31:26 +02:00
Mapika and Joost VandeVondele
1b6975ac41
Add quiet move streak tracking to search stack
...
Passed STC:
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 109344 W: 28473 L: 28053 D: 52818
Ptnml(0-2): 320, 12756, 28085, 13206, 305
https://tests.stockfishchess.org/tests/view/6828c43e6ec7634154f99a10
Passed LTC:
LLR: 2.96 (-2.94,2.94) <0.50,2.50>
Total: 76308 W: 19721 L: 19323 D: 37264
Ptnml(0-2): 39, 8145, 21386, 8547, 37
https://tests.stockfishchess.org/tests/view/6828f65a6ec7634154f99b72
closes https://github.com/official-stockfish/Stockfish/pull/6066
Bench: 2161814
2025-05-19 07:27:26 +02:00
Shawn Xu and Joost VandeVondele
6f445631ab
Simplify Futility Margin
...
Passed STC Non-regression:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 159008 W: 41500 L: 41414 D: 76094
Ptnml(0-2): 501, 18821, 40759, 18937, 486
https://tests.stockfishchess.org/tests/view/680ff9e23629b02d74b1663a
Passed LTC Non-regression:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 163572 W: 41617 L: 41543 D: 80412
Ptnml(0-2): 90, 17755, 46024, 17825, 92
https://tests.stockfishchess.org/tests/view/6814dd973629b02d74b16bac
closes https://github.com/official-stockfish/Stockfish/pull/6065
Bench: 2018775
2025-05-19 07:22:20 +02:00
Shawn Xu and Joost VandeVondele
6b7e05f0c5
Simplify PCM TTMove Bonus
...
Passed Non-regression STC:
LLR: 2.97 (-2.94,2.94) <-1.75,0.25>
Total: 114048 W: 29597 L: 29459 D: 54992
Ptnml(0-2): 315, 13619, 29045, 13703, 342
https://tests.stockfishchess.org/tests/view/681e83533629b02d74b17701
Passed Non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 61014 W: 15582 L: 15405 D: 30027
Ptnml(0-2): 25, 6485, 17307, 6668, 22
https://tests.stockfishchess.org/tests/view/68226b523629b02d74b17b89
closes https://github.com/official-stockfish/Stockfish/pull/6061
bench 2016566
2025-05-19 07:13:39 +02:00
FauziAkram and Disservin
c4e2479a75
Introducing a depth component to the penalty.
...
Passed STC:
LLR: 2.97 (-2.94,2.94) <0.00,2.00>
Total: 31648 W: 8358 L: 8050 D: 15240
Ptnml(0-2): 78, 3596, 8182, 3876, 92
https://tests.stockfishchess.org/tests/view/680fa73d3629b02d74b165a9
Passed LTC:
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 177720 W: 45524 L: 44920 D: 87276
Ptnml(0-2): 91, 19130, 49813, 19736, 90
https://tests.stockfishchess.org/tests/view/68109e2c3629b02d74b166ee
closes https://github.com/official-stockfish/Stockfish/pull/6060
Bench: 2251724
2025-05-13 20:47:50 +02:00
Shawn Xu and Disservin
b5f11085dd
Do more extensions in nodes far from the root
...
Parameters found by @FauziAkram in the latest tune.
Passed VVLTC w/ LTC Bound:
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 243264 W: 63452 L: 62774 D: 117038
Ptnml(0-2): 18, 22494, 75934, 23164, 22
https://tests.stockfishchess.org/tests/view/680e82b23629b02d74b15e27
Passed VVLTC w/ STC Bound:
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 37838 W: 9935 L: 9667 D: 18236
Ptnml(0-2): 6, 3383, 11873, 3651, 6
https://tests.stockfishchess.org/tests/view/681e707a3629b02d74b176e8
STC Elo Estimate:
Elo: -0.49 ± 2.4 (95%) LOS: 34.8%
Total: 20000 W: 5118 L: 5146 D: 9736
Ptnml(0-2): 55, 2365, 5182, 2349, 49
nElo: -0.96 ± 4.8 (95%) PairsRatio: 0.99
https://tests.stockfishchess.org/tests/view/6822af4b3629b02d74b17be6
closes https://github.com/official-stockfish/Stockfish/pull/6059
Bench: 2135382
2025-05-13 20:46:27 +02:00
Daniel Monroe and Disservin
1f9af9966f
Simplify futility pruning term
...
Passed simplification STC
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 49920 W: 12933 L: 12727 D: 24260
Ptnml(0-2): 141, 5865, 12752, 6051, 151
https://tests.stockfishchess.org/tests/view/681d01d33629b02d74b1756e
Passed simplification LTC
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 68808 W: 17573 L: 17402 D: 33833
Ptnml(0-2): 23, 7343, 19511, 7494, 33
https://tests.stockfishchess.org/tests/view/681e33843629b02d74b176b1
closes https://github.com/official-stockfish/Stockfish/pull/6058
Bench: 2041086
2025-05-13 20:42:36 +02:00
