jirayu_sri/stockfish
1
0
Fork 0
mirror of https://github.com/official-stockfish/Stockfish.git synced 2026-07-22 12:47:08 +00:00
Code Issues Packages Projects Releases Wiki Activity
6,820 Commits 6 Branches 60 Tags
e7a4708ad558da49f88c8c72aed8c9290fef8d05
Commit Graph
100 Commits
This Branch
This Branch
All Branches
Author SHA1 Message Date
Shawn XuandJoost VandeVondele e5c2dc5edd remove clang-format workaround 
closes https://github.com/official-stockfish/Stockfish/pull/6332

No functional change
 2025-10-05 09:33:42 +02:00
Shawn XuandJoost VandeVondele 5895f47dab Further simplify low ply history in evasions 
Passed Non-regression STC (vs #6308):
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 174208 W: 45414 L: 45343 D: 83451
Ptnml(0-2): 633, 20324, 45095, 20443, 609
https://tests.stockfishchess.org/tests/view/68c24be359efc3c96b611487

Passed Non-regression LTC (vs #6308):
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 110070 W: 28099 L: 27969 D: 54002
Ptnml(0-2): 56, 11919, 30962, 12035, 63
https://tests.stockfishchess.org/tests/view/68c4efa559efc3c96b611dfc

closes https://github.com/official-stockfish/Stockfish/pull/6321

Bench: 2151873
 2025-10-05 09:18:16 +02:00
Shawn XuandJoost VandeVondele 3073d82ccf Simplify use of low-ply history in evasions 
Passed Non-regression STC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 65024 W: 16991 L: 16804 D: 31229
Ptnml(0-2): 182, 7423, 17119, 7602, 186
https://tests.stockfishchess.org/tests/view/68c23f5459efc3c96b6113df

Passed Non-regression LTC:
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 207312 W: 53126 L: 53095 D: 101091
Ptnml(0-2): 126, 21986, 59389, 22041, 114
https://tests.stockfishchess.org/tests/view/68c241e359efc3c96b6113ef

closes https://github.com/official-stockfish/Stockfish/pull/6308

Bench: 2515619
 2025-09-28 21:21:57 +02:00
Shawn XuandJoost VandeVondele c62e71e78f Simplify a separate term in low ply history bonus formula 
Passed Non-regression STC:
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 211200 W: 54887 L: 54860 D: 101453
Ptnml(0-2): 719, 24894, 54296, 25023, 668
https://tests.stockfishchess.org/tests/view/68c21e7f59efc3c96b6112c8

Passed Non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 217842 W: 55587 L: 55568 D: 106687
Ptnml(0-2): 130, 23651, 61313, 23724, 103
https://tests.stockfishchess.org/tests/view/68c230ec59efc3c96b61135a

closes https://github.com/official-stockfish/Stockfish/pull/6307

Bench: 2070860
 2025-09-28 21:19:22 +02:00
Shawn XuandJoost VandeVondele 415a1ad426 Simplify Probcut Clamp Further 
Passed Non-regression STC:
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 157984 W: 41116 L: 41030 D: 75838
Ptnml(0-2): 568, 18570, 40601, 18714, 539
https://tests.stockfishchess.org/tests/view/68b750518f94a4e5a7fe76cd

Passed Non-regression LTC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 335232 W: 85443 L: 85543 D: 164246
Ptnml(0-2): 177, 36616, 94137, 36502, 184
https://tests.stockfishchess.org/tests/view/68bc767259efc3c96b61076b

closes https://github.com/official-stockfish/Stockfish/pull/6303

Bench: 2213844
 2025-09-28 21:12:01 +02:00
Shawn XuJoost VandeVondeleDaniel Monroe
 		7a36c0e95f Remove quiet move streak 
Passed Non-regression STC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 67712 W: 17744 L: 17555 D: 32413
Ptnml(0-2): 204, 8030, 17274, 8069, 279
https://tests.stockfishchess.org/tests/view/68b784628f94a4e5a7fe7706

Passed Non-regression LTC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 196050 W: 50270 L: 50228 D: 95552
Ptnml(0-2): 122, 21465, 54813, 21499, 126
https://tests.stockfishchess.org/tests/view/68ba119d8f94a4e5a7fe7941

closes https://github.com/official-stockfish/Stockfish/pull/6299

Bench: 2238789

Co-authored-by: Daniel Monroe <github.com@danielmonroe.net>
 2025-09-28 21:08:58 +02:00
Shawn XuandJoost VandeVondele d5f152b5df Reintroduce #6259 
Reintroduces af181d9, which no longer regresses on matetrack after #6286

Using ./stockfish on matetrack.epd with --nodes 1000000
Engine ID:     Stockfish dev-20250902-adfddd2c
Total FENs:    6554
Found mates:   3490
Best mates:    2429

Passed Non-regression LTC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 37608 W: 9726 L: 9523 D: 18359
Ptnml(0-2): 16, 4001, 10578, 4182, 27
https://tests.stockfishchess.org/tests/view/68b886778f94a4e5a7fe77d9

closes https://github.com/official-stockfish/Stockfish/pull/6289

Bench: 2493363
 2025-09-06 07:55:14 +02:00
Shawn XuandJoost VandeVondele adfddd2c98 Add scaling note to STC/LTC tunes 
It has been repeatedly shown that such tunes are suspectible to become
anti-scaling. Below are some recent examples:

https://github.com/official-stockfish/Stockfish/commit/2e91a8635468e40c89a2303ce50384864d088611
https://github.com/official-stockfish/Stockfish/commit/d11f49b790429c236a1a4169f0d8052635fc03dc

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

Revert 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

Revert 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

https://tests.stockfishchess.org/tests/view/688cf38bf17748b4d23c8057
https://tests.stockfishchess.org/tests/view/6890bc7792fcad741b804a19

Passed LTC:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 74928 W: 19466 L: 19071 D: 36391
Ptnml(0-2): 37, 8048, 20901, 8439, 39

Failed Non-regression VLTC:
LLR: -2.94 (-2.94,2.94) <-1.75,0.25>
Total: 57704 W: 14643 L: 14928 D: 28133
Ptnml(0-2): 5, 5925, 17280, 5634, 8
https://tests.stockfishchess.org/tests/view/6890bc7792fcad741b804a19

(Note that an STC-tuned version passed non-regression, but was shortly
simplified)

https://github.com/official-stockfish/Stockfish/pull/6040

Passed STC:
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 27776 W: 7352 L: 7054 D: 13370
Ptnml(0-2): 68, 3126, 7221, 3386, 87
https://tests.stockfishchess.org/tests/view/680ec0f83629b02d74b1605b

Passed LTC:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 161304 W: 41432 L: 40864 D: 79008
Ptnml(0-2): 61, 17305, 45357, 17863, 66
https://tests.stockfishchess.org/tests/view/680ec7f93629b02d74b16084

Failed Non-regression VVLTC:
LLR: -2.94 (-2.94,2.94) <-1.75,0.25>
Total: 313466 W: 80573 L: 81089 D: 151804
Ptnml(0-2): 38, 29689, 97782, 29199, 25
https://tests.stockfishchess.org/tests/view/6810d0533629b02d74b16756

https://github.com/official-stockfish/Stockfish/pull/5907
https://github.com/official-stockfish/Stockfish/pull/5887

Passed LTC with STC bounds:
https://tests.stockfishchess.org/tests/view/67b115dd6c6b9e172ad1592f
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 75756 W: 19393 L: 19044 D: 37319
Ptnml(0-2): 60, 8251, 20913, 8588, 66

Passed LTC with LTC bounds:
https://tests.stockfishchess.org/tests/view/67af5f5d6c6b9e172ad15765
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 108126 W: 27880 L: 27412 D: 52834
Ptnml(0-2): 85, 11786, 29866, 12228, 98

Revert VVLTC w/ STC bounds:
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 56342 W: 14536 L: 14246 D: 27560
Ptnml(0-2): 7, 5061, 17741, 5359, 3
https://tests.stockfishchess.org/tests/view/67be4f8ad8d5c2c657c52d10

Revert VVLTC w/ LTC bounds:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 66562 W: 17364 L: 17016 D: 32182
Ptnml(0-2): 3, 6145, 20637, 6493, 3
https://tests.stockfishchess.org/tests/view/67bcd25ff6b602bd7222ea40

closes https://github.com/official-stockfish/Stockfish/pull/6284

no functional change
 2025-09-02 20:42:03 +02:00
Shawn XuandJoost VandeVondele f2da0ccf3f Simplify SMP Reduction 
Passed Non-regression SMP STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 232784 W: 59845 L: 59841 D: 113098
Ptnml(0-2): 289, 26459, 62934, 26379, 331
https://tests.stockfishchess.org/tests/view/68ab96bf75da51a345a5acd6

Passed Non-regression SMP LTC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 374270 W: 95978 L: 96113 D: 182179
Ptnml(0-2): 118, 38575, 109888, 38432, 122
https://tests.stockfishchess.org/tests/view/68abcf1c75da51a345a5adb6

closes https://github.com/official-stockfish/Stockfish/pull/6285

Bench: 2667107
 2025-09-02 20:41:08 +02:00
Shawn XuandJoost VandeVondele 75ac6c7a06 simplify stalemate further 
Non-regression STC:
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 155200 W: 40650 L: 40562 D: 73988
Ptnml(0-2): 533, 17588, 41258, 17700, 521
https://tests.stockfishchess.org/tests/view/68abe11375da51a345a5adec

Non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 82824 W: 21442 L: 21287 D: 40095
Ptnml(0-2): 51, 8738, 23675, 8901, 47
https://tests.stockfishchess.org/tests/view/68b205606217b8721dca9c8e

10k Stalemate:
Elo: 1.46 ± 1.2 (95%) LOS: 99.0%
Total: 10000 W: 4640 L: 4598 D: 762
Ptnml(0-2): 0, 140, 4678, 182, 0
https://tests.stockfishchess.org/tests/view/68b2059b6217b8721dca9c90

closes https://github.com/official-stockfish/Stockfish/pull/6283

Bench: 2431727
 2025-09-02 20:39:02 +02:00
Shawn XuandJoost 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
Shawn XuJoost VandeVondeleDaniel Monroe
 		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 XuandJoost 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
Shawn XuandJoost 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
Shawn XuandJoost 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 XuandJoost 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 XuandJoost 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
Shawn XuandJoost 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
Shawn XuandJoost 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
Shawn XuandDisservin 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
Shawn XuandJoost 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
Shawn XuandJoost 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
Shawn XuandJoost VandeVondele c9af7674bc Introduce Secondary TT Aging 
When a high-depth TT entry fail to produce a cutoff, decrease the stored depth
by 1. This is intended to help cases such as #5023
(https://github.com/official-stockfish/Stockfish/issues/5023#issuecomment-2814209391),
where entries with extremely high depths prevent TT cutoffs, contributing to
search explosions.

Passed STC:
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 128800 W: 33502 L: 33053 D: 62245
Ptnml(0-2): 331, 15084, 33149, 15477, 359
https://tests.stockfishchess.org/tests/view/683958e56ec7634154f9d2a9

Passed LTC:
LLR: 2.97 (-2.94,2.94) <0.50,2.50>
Total: 63288 W: 16376 L: 16005 D: 30907
Ptnml(0-2): 26, 6712, 17798, 7081, 27
https://tests.stockfishchess.org/tests/view/683aa4026ec7634154f9d469

closes https://github.com/official-stockfish/Stockfish/pull/6113

Bench: 2144705
 2025-06-02 21:55:55 +02:00
Shawn XuandJoost 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
Shawn XuandJoost VandeVondele dc85c5a4c9 Remove nnz lookup table load optimization 
Passed Non-regression STC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 63296 W: 16491 L: 16311 D: 30494
Ptnml(0-2): 129, 6624, 17972, 6784, 139
https://tests.stockfishchess.org/tests/view/6833ce486ec7634154f9cb22

Passed 2nd Non-regression STC:
LLR: 2.97 (-2.94,2.94) <-1.75,0.25>
Total: 369568 W: 95314 L: 95451 D: 178803
Ptnml(0-2): 897, 40231, 102601, 40222, 833
https://tests.stockfishchess.org/tests/view/68355c956ec7634154f9ce07

closes https://github.com/official-stockfish/Stockfish/pull/6100

no functional change
 2025-06-02 21:21:54 +02:00
Shawn XuandJoost 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
Shawn XuandJoost VandeVondele e6ec4705a8 Remove deprecated arch from codeql 
closes https://github.com/official-stockfish/Stockfish/pull/6090

no functional change
 2025-05-25 21:00:38 +02:00
Shawn XuandJoost VandeVondele 472cc764be Move SIMD code to a separate header 
Passed Non-regression STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 115328 W: 29903 L: 29777 D: 55648
Ptnml(0-2): 265, 12293, 32444, 12375, 287
https://tests.stockfishchess.org/tests/view/68300e086ec7634154f9b1d1

closes https://github.com/official-stockfish/Stockfish/pull/6086

no functional change
 2025-05-25 20:52:57 +02:00
Shawn XuandJoost VandeVondele 347e328fdb Simplify TT Replacement Strategy 
Passed Non-regression STC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 50528 W: 13160 L: 12958 D: 24410
Ptnml(0-2): 132, 5681, 13439, 5877, 135
https://tests.stockfishchess.org/tests/view/682a8b296ec7634154f9a785

Passed Non-regression STC w/ High Hash Pressure:
LLR: 2.98 (-2.94,2.94) <-1.75,0.25>
Total: 30048 W: 7849 L: 7621 D: 14578
Ptnml(0-2): 75, 3390, 7884, 3582, 93
https://tests.stockfishchess.org/tests/view/682a9caf6ec7634154f9a7ae

Passed Non-regression LTC w/ High Hash Pressure:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 17610 W: 4584 L: 4362 D: 8664
Ptnml(0-2): 7, 1799, 4974, 2015, 10
https://tests.stockfishchess.org/tests/view/682ab3966ec7634154f9a8c8

closes https://github.com/official-stockfish/Stockfish/pull/6079

Bench: 2422771
 2025-05-19 20:49:28 +02:00
Shawn XuandJoost 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 XuandJoost 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
Shawn XuandJoost 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 XuandJoost VandeVondele e4b0f37493 Shrink Enum Sizes 
Passed STC:
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 110848 W: 28974 L: 28564 D: 53310
Ptnml(0-2): 302, 12118, 30132, 12612, 260
https://tests.stockfishchess.org/tests/view/68242770a527315e07ccca38

closes https://github.com/official-stockfish/Stockfish/pull/6063

no functional change
 2025-05-19 07:17:39 +02:00
Shawn XuandJoost 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
Shawn XuandDisservin 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
Shawn XuandDisservin e9925b122f Simplify ttCapture LMR 
Passed Non-regression STC:
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 51104 W: 13389 L: 13184 D: 24531
Ptnml(0-2): 182, 5940, 13068, 6215, 147
https://tests.stockfishchess.org/tests/view/680ef2503629b02d74b16498

Passed Non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 73350 W: 18804 L: 18638 D: 35908
Ptnml(0-2): 30, 7906, 20639, 8068, 32
https://tests.stockfishchess.org/tests/view/6810510e3629b02d74b1668a

closes https://github.com/official-stockfish/Stockfish/pull/6044

Bench: 1805151
 2025-05-13 20:36:42 +02:00
Shawn XuandDisservin 81cc004060 Remove risk tolerance 
Passed STC:
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 379328 W: 97567 L: 97724 D: 184037
Ptnml(0-2): 909, 44861, 98314, 44638, 942
https://tests.stockfishchess.org/tests/view/680defc63629b02d74b15b62

Passed LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 160752 W: 40762 L: 40685 D: 79305
Ptnml(0-2): 60, 17548, 45091, 17609, 68
https://tests.stockfishchess.org/tests/view/680e8ff43629b02d74b15e65

closes https://github.com/official-stockfish/Stockfish/pull/6037

Bench: 1897340
 2025-05-13 20:31:37 +02:00
Shawn XuandDisservin b0a7a34d3f Simplify malus calculation 
closes https://github.com/official-stockfish/Stockfish/pull/6024

No functional change
 2025-04-27 19:43:47 +02:00
Shawn XuandDisservin 4e49f8dff9 Clean up search 
* Correct IIR scaling comments
* Replace `(PvNode || cutNode)` with `!allNode`
* Consistent formatting for scaler tags
* Add comments to some recently-introduced LMR terms
* Add comments on PCM bonus tweaks

Passed Non-regression STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 389472 W: 102457 L: 102622 D: 184393
Ptnml(0-2): 1676, 41887, 107798, 41676, 1699
https://tests.stockfishchess.org/tests/view/67a0ea670774dfd78deb23cd

closes https://github.com/official-stockfish/Stockfish/pull/5854

Bench: 1585741
 2025-04-27 19:26:02 +02:00
Shawn XuandJoost VandeVondele 4176ad7b0a simplify risk tolerance 
Passed Non-regression STC:
LLR: 2.98 (-2.94,2.94) <-1.75,0.25>
Total: 73408 W: 19028 L: 18844 D: 35536
Ptnml(0-2): 201, 8709, 18743, 8807, 244
https://tests.stockfishchess.org/tests/view/68051f3698cd372e3ae9f63a

Passed Non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 91236 W: 23193 L: 23045 D: 44998
Ptnml(0-2): 34, 9908, 25599, 10030, 47
https://tests.stockfishchess.org/tests/view/6805239498cd372e3ae9fa41

closes https://github.com/official-stockfish/Stockfish/pull/6000

bench 1864632
 2025-04-26 21:49:38 +02:00
Shawn XuandJoost VandeVondele 16cd38dba1 Tweak TT Move Reduction by TT Move History 
Passed STC:
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 62496 W: 16197 L: 15844 D: 30455
Ptnml(0-2): 200, 7234, 16011, 7619, 184
https://tests.stockfishchess.org/tests/view/67f7fa9b31d7cf8afdc4609c

Passed LTC:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 400470 W: 102068 L: 101012 D: 197390
Ptnml(0-2): 201, 43207, 112347, 44295, 185
https://tests.stockfishchess.org/tests/view/67f927b0cd501869c66975e0

Passed VVLTC Non-regression:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 125394 W: 32408 L: 32304 D: 60682
Ptnml(0-2): 3, 11702, 39188, 11796, 8
https://tests.stockfishchess.org/tests/view/6804c215cd501869c66986b9

closes https://github.com/official-stockfish/Stockfish/pull/5998

bench 1760988
 2025-04-26 21:43:11 +02:00
Shawn XuandJoost VandeVondele b915ed702a remove StateInfo::next 
unused.

closes https://github.com/official-stockfish/Stockfish/pull/5997

no functional change
 2025-04-26 21:37:17 +02:00
Shawn XuandJoost VandeVondele f273eea71f Remove non-functional accumulator reset 
Passed Non-regression STC:
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 219360 W: 56600 L: 56583 D: 106177
Ptnml(0-2): 582, 23419, 61620, 23518, 541
https://tests.stockfishchess.org/tests/view/67fad20dcd501869c669780f

closes https://github.com/official-stockfish/Stockfish/pull/5986

no functional change
 2025-04-26 21:30:01 +02:00
Shawn XuandDisservin 2b4926e091 Simplify TT Move History 
Part 1 passed Non-regression STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 195552 W: 50394 L: 50349 D: 94809
Ptnml(0-2): 581, 23222, 50122, 23273, 578
https://tests.stockfishchess.org/tests/view/67eb6ea831d7cf8afdc44c30

Part 2 passed Non-regression STC:
LLR: 2.92 (-2.94,2.94) <-1.75,0.25>
Total: 181664 W: 46786 L: 46727 D: 88151
Ptnml(0-2): 517, 21403, 46974, 21380, 558
https://tests.stockfishchess.org/tests/view/67eb6f3331d7cf8afdc44c33

Passed Non-regression LTC:
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 155454 W: 39496 L: 39412 D: 76546
Ptnml(0-2): 77, 16950, 43580, 17052, 68
https://tests.stockfishchess.org/tests/view/67eee76531d7cf8afdc45358

Passed Non-regression VLTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 118266 W: 30263 L: 30148 D: 57855
Ptnml(0-2): 11, 11844, 35309, 11957, 12
https://tests.stockfishchess.org/tests/view/67f2414a31d7cf8afdc45760

closes https://github.com/official-stockfish/Stockfish/pull/5987

Bench: 1792850
 2025-04-18 14:32:26 +02:00
Shawn XuandDisservin d7c04a9429 Introduce TT Move History Double Extensions 
Passed VVLTC w/ STC bounds:
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 74918 W: 19436 L: 19120 D: 36362
Ptnml(0-2): 6, 6890, 23354, 7200, 9
https://tests.stockfishchess.org/tests/view/67e4a1088888403457d878bb

Passed VVLTC w/ LTC bounds:
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 111706 W: 29050 L: 28619 D: 54037
Ptnml(0-2): 13, 10218, 34959, 10651, 12
https://tests.stockfishchess.org/tests/view/67d6877c517865b4a2dfd36b

STC Elo Estimate:
Elo: 1.26 ± 2.0 (95%) LOS: 88.8%
Total: 30000 W: 7855 L: 7746 D: 14399
Ptnml(0-2): 104, 3531, 7630, 3622, 113
nElo: 2.44 ± 3.9 (95%) PairsRatio: 1.03
https://tests.stockfishchess.org/tests/view/67eacb8c31d7cf8afdc44b99

closes https://github.com/official-stockfish/Stockfish/pull/5961

Bench: 1887897
 2025-04-02 17:53:05 +02:00
Shawn XuandDisservin d2cb927a04 Simplify TT cutoff conthist updates 
Passed Non-regression STC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 86304 W: 22251 L: 22084 D: 41969
Ptnml(0-2): 250, 10214, 22123, 10249, 316
https://tests.stockfishchess.org/tests/view/67db60cd8c7f315cc372aae7

Passed Non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 199158 W: 50655 L: 50617 D: 97886
Ptnml(0-2): 103, 21579, 56182, 21607, 108
https://tests.stockfishchess.org/tests/view/67dcdc5b8c7f315cc372ac12

closes https://github.com/official-stockfish/Stockfish/pull/5945

Bench: 2069191
 2025-04-02 17:37:02 +02:00
Shawn XuandDisservin ee35a51c40 Remove extra division 
closes https://github.com/official-stockfish/Stockfish/pull/5943

No functional change
 2025-04-02 17:34:37 +02:00
Shawn XuandDisservin c2ff7a95c3 Cleanup fused updates 
Passed Non-regression STC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 70656 W: 18257 L: 18077 D: 34322
Ptnml(0-2): 217, 7912, 18879, 8114, 206
https://tests.stockfishchess.org/tests/view/67e23ae78888403457d876d4

closes https://github.com/official-stockfish/Stockfish/pull/5941

No functional change
 2025-04-02 17:34:31 +02:00
Shawn XuandDisservin 9045f17c3f Simplify captures PCM 
Passed Non-regression STC:
LLR: 2.92 (-2.94,2.94) <-1.75,0.25>
Total: 229856 W: 59258 L: 59252 D: 111346
Ptnml(0-2): 746, 27330, 58714, 27448, 690
https://tests.stockfishchess.org/tests/view/67d3fdac517865b4a2dfcef4

Passed Non-regression LTC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 107652 W: 27470 L: 27338 D: 52844
Ptnml(0-2): 56, 11646, 30280, 11798, 46
https://tests.stockfishchess.org/tests/view/67d5f972517865b4a2dfd2ec

closes https://github.com/official-stockfish/Stockfish/pull/5931

Bench: 1842520
 2025-03-21 11:19:45 +01:00
Shawn XuandDisservin fc0e0a44d4 Refactor accumulator storage/updates 
Passed Non-regression STC:
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 115840 W: 29983 L: 29854 D: 56003
Ptnml(0-2): 338, 12990, 31149, 13091, 352
https://tests.stockfishchess.org/tests/view/67d0a044166a3e8781d84223

closes https://github.com/official-stockfish/Stockfish/pull/5927

No functional change
 2025-03-21 11:12:47 +01:00
Shawn XuandDisservin 66aee01bb1 Simplify Return Value Adjustment Condition 
Passed Non-regression STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 82112 W: 21281 L: 21110 D: 39721
Ptnml(0-2): 258, 9630, 21112, 9795, 261
https://tests.stockfishchess.org/tests/view/67c42528b7226b5d8a2dd3a0

Passed Non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 182652 W: 46295 L: 46240 D: 90117
Ptnml(0-2): 103, 20025, 51003, 20104, 91
https://tests.stockfishchess.org/tests/view/67c4d56b685e87e15e7c43d8

closes https://github.com/official-stockfish/Stockfish/pull/5925

Bench: 1711791
 2025-03-21 11:11:12 +01:00
Shawn XuandDisservin e3660b47bd Add dbg_clear helper function 
closes https://github.com/official-stockfish/Stockfish/pull/5921

No functional change
 2025-03-21 11:09:28 +01:00
Shawn XuandDisservin b825ea6e57 Improve Perft Testing 
Added #5909 problematic position and chess-library DFRC positions to
perft testing. Additional work done by @Disservin to clean up and
improve error reporting.

closes https://github.com/official-stockfish/Stockfish/pull/5917

No functional change

Co-authored-by: disservin <disservin.social@gmail.com>
 2025-03-21 11:03:31 +01:00
Shawn XuDisservinRobert Nürnberggab8192
 		99d32e395e Reapply #5909 
This version fixes the logic of `gives_check`, which was identified to
be the cause of illegal moves.

closes https://github.com/official-stockfish/Stockfish/pull/5914

No functional change

Co-authored-by: Robert Nürnberg <robert.nurnberg@gmx.de>
Co-authored-by: gab8192 <gabrilomba57@gmail.com>
 2025-03-21 11:02:19 +01:00
Shawn XuandDisservin 09faa62621 Simplify NMP Conditions 
Passed Non-regression STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 142400 W: 36883 L: 36779 D: 68738
Ptnml(0-2): 467, 16804, 36571, 16874, 484
https://tests.stockfishchess.org/tests/view/67bd1898e4a8d7152b974ef1

Passed Non-regression LTC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 251868 W: 63905 L: 63920 D: 124043
Ptnml(0-2): 133, 27480, 70708, 27495, 118
https://tests.stockfishchess.org/tests/view/67bd1898e4a8d7152b974ef1

closes https://github.com/official-stockfish/Stockfish/pull/5906

Bench: 2188400
 2025-02-27 20:31:04 +01:00
Shawn XuandDisservin 43b2d65d72 Add scaling note to futility pruning 
Note that both patches below effectively reduces the frequency of futility pruning.

Passed STC:
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 51680 W: 13599 L: 13253 D: 24828
Ptnml(0-2): 217, 6056, 12959, 6380, 228
https://tests.stockfishchess.org/tests/view/67ac218fa04df5eb8dbebf26

Passed LTC:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 51798 W: 13338 L: 12986 D: 25474
Ptnml(0-2): 42, 5584, 14310, 5906, 57
https://tests.stockfishchess.org/tests/view/67acf04152879dfd14d7e846

Regression at STC SMP:
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 231552 W: 60226 L: 59642 D: 111684
Ptnml(0-2): 565, 25994, 62031, 26664, 522
https://tests.stockfishchess.org/tests/view/67ae390c1a4c73ae1f930dbf

Passed STC:
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 22560 W: 6022 L: 5725 D: 10813
Ptnml(0-2): 87, 2524, 5762, 2819, 88
https://tests.stockfishchess.org/tests/view/67ac202aa04df5eb8dbebf22

Passed LTC:
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 66138 W: 16953 L: 16572 D: 32613
Ptnml(0-2): 62, 7103, 18360, 7480, 64
https://tests.stockfishchess.org/tests/view/67ad47d852879dfd14d7e899

Regression at VVLTC SMP:
LLR: -2.94 (-2.94,2.94) <-1.75,0.25>
Total: 29138 W: 7408 L: 7655 D: 14075
Ptnml(0-2): 0, 2816, 9189, 2559, 5
https://tests.stockfishchess.org/tests/view/67b159ce6c6b9e172ad1598f

closes https://github.com/official-stockfish/Stockfish/pull/5888

No functional change
 2025-02-24 19:09:52 +01:00
Shawn XuandJoost VandeVondele d66e603070 Increase PCM bonus when cutOffCnt is low 
Passed STC:
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 36832 W: 9763 L: 9438 D: 17631
Ptnml(0-2): 159, 4267, 9254, 4562, 174
https://tests.stockfishchess.org/tests/view/67a29dbafedef70e42ac329a

Passed LTC:
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 19728 W: 5124 L: 4839 D: 9765
Ptnml(0-2): 18, 2029, 5485, 2314, 18
https://tests.stockfishchess.org/tests/view/67a2a1abfedef70e42ac32b7

closes https://github.com/official-stockfish/Stockfish/pull/5865

Bench: 3197798
 2025-02-05 19:00:25 +01:00
Shawn XuandDisservin 8c73472ac8 Simplify depth increase condition further 
Passed Non-regression STC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 51232 W: 13560 L: 13351 D: 24321
Ptnml(0-2): 183, 6075, 12920, 6226, 212
https://tests.stockfishchess.org/tests/view/679d7b2b0774dfd78deb043f

Passed Non-regression LTC (v. #5827):
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 172398 W: 44108 L: 44042 D: 84248
Ptnml(0-2): 122, 19207, 47489, 19245, 136
https://tests.stockfishchess.org/tests/view/679d7fb10774dfd78deb05d2

Passed Non-regression VLTC (v. #5827):
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 388540 W: 99314 L: 99464 D: 189762
Ptnml(0-2): 89, 40454, 113350, 40272, 105
https://tests.stockfishchess.org/tests/view/679da3be0774dfd78deb0ad4

closes https://github.com/official-stockfish/Stockfish/pull/5846

Bench: 2688175
 2025-02-04 21:11:37 +01:00
Shawn XuandDisservin 344e89275a Simplify Away Quadruple Extensions 
Passed Non-regression LTC:
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 95856 W: 24551 L: 24404 D: 46901
Ptnml(0-2): 85, 10621, 26364, 10778, 80
https://tests.stockfishchess.org/tests/view/679a9aedae346be6da0eebd6

Passed Non-regression VLTC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 157536 W: 40000 L: 39921 D: 77615
Ptnml(0-2): 43, 16416, 45775, 16487, 47
https://tests.stockfishchess.org/tests/view/679aed8f51037ccaf3e30fbf

Passed Non-regression VVLTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 51598 W: 13345 L: 13172 D: 25081
Ptnml(0-2): 0, 4735, 16162, 4896, 6
https://tests.stockfishchess.org/tests/view/679d368b0774dfd78deb0163

closes https://github.com/official-stockfish/Stockfish/pull/5843

Bench: 2399312
 2025-02-02 13:44:22 +01:00
Shawn XuandDisservin 4a77fb213f Clean up corrhist 
Passed Non-regression STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 89056 W: 23225 L: 23067 D: 42764
Ptnml(0-2): 292, 9688, 24470, 9726, 352
https://tests.stockfishchess.org/tests/view/679816b2ae346be6da0ee8e7

closes https://github.com/official-stockfish/Stockfish/pull/5830

Bench: 1767398
 2025-02-02 13:33:35 +01:00
Shawn XuJoost VandeVondeleAndrew Grant
 		889fed448c Better nonpawn indexing 
Improves indexing scheme, by noting that both sides are likely to access the same non_pawn_index nearby.

LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 75936 W: 19905 L: 19554 D: 36477
Ptnml(0-2): 190, 7863, 21554, 8128, 233
https://tests.stockfishchess.org/tests/view/67904d0cfc8c306ba6cea332

closes https://github.com/official-stockfish/Stockfish/pull/5816

No functional change

Co-authored-by: Andrew Grant <andrew.github@grantnet.us>
 2025-01-25 20:53:53 +01:00
Shawn XuandJoost VandeVondele d606311e55 Fix undefined behavior 
From cppreference: "It is undefined behavior to read from the member of the
union that wasn't most recently written. Many compilers implement, as a
non-standard language extension, the ability to read inactive members of a
union."

closes https://github.com/official-stockfish/Stockfish/pull/5811

no functional change
 2025-01-25 20:33:43 +01:00
Shawn XuandJoost VandeVondele e7367cef0f Clean up pack reordering 
closes https://github.com/official-stockfish/Stockfish/pull/5802

no functional change
 2025-01-25 20:17:39 +01:00
Shawn XuandJoost VandeVondele 62ecdfe82c simplify accumulator updates 
After #5759 accumulator updates are strictly on a per-move basis. Therefore, the generic code for updating multiple moves at once is no longer needed.

Passed Non-regression STC:
LLR: 3.00 (-2.94,2.94) <-1.75,0.25>
Total: 81696 W: 21204 L: 21039 D: 39453
Ptnml(0-2): 210, 8431, 23416, 8566, 225
https://tests.stockfishchess.org/tests/view/67823a24a31c4c13e83518a8

closes https://github.com/official-stockfish/Stockfish/pull/5760

no functional change
 2025-01-25 20:09:09 +01:00
Shawn XuandJoost VandeVondele 738ac2a100 tuned TM values 
Tuned 70k games at 240+2.4 th 2: https://tests.stockfishchess.org/tests/view/6783b1b16ddf09c0b4b703f5

Failed STC:
LLR: -2.93 (-2.94,2.94) <0.00,2.00>
Total: 491872 W: 128260 L: 127804 D: 235808
Ptnml(0-2): 1579, 55449, 131572, 55609, 1727
https://tests.stockfishchess.org/tests/view/6785a045460e2910c51de4b8

Passed LTC:
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 154824 W: 39315 L: 38874 D: 76635
Ptnml(0-2): 110, 15809, 45147, 16222, 124
https://tests.stockfishchess.org/tests/view/678ac722c00c743bc9e9fc35

Passed VLTC:
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 77404 W: 19825 L: 19452 D: 38127
Ptnml(0-2): 18, 7262, 23765, 7643, 14
https://tests.stockfishchess.org/tests/view/678b2a98c00c743bc9ea048c

closes https://github.com/official-stockfish/Stockfish/pull/5796

No functional change
 2025-01-18 21:24:01 +01:00
Shawn XuandJoost VandeVondele ccbd060b01 simplify razoring 
Passed Non-regression STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 93056 W: 24215 L: 24054 D: 44787
Ptnml(0-2): 364, 11085, 23470, 11244, 365
https://tests.stockfishchess.org/tests/view/67883a5d3b8f206a2696b804

Passed Non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 66564 W: 16971 L: 16794 D: 32799
Ptnml(0-2): 56, 7403, 18192, 7570, 61
https://tests.stockfishchess.org/tests/view/6789ffa78082388fa0cbfe95

closes https://github.com/official-stockfish/Stockfish/pull/5788

bench 1500649
 2025-01-18 20:54:55 +01:00
Shawn XuandDisservin 921361829a Simplify away capthist bonus in Probcut 
The explicit bonus has been obsoleted with the introduction of #5695

Passed Non-regression STC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 132832 W: 34519 L: 34403 D: 63910
Ptnml(0-2): 430, 15754, 33931, 15872, 429
https://tests.stockfishchess.org/tests/view/678158c49168c8bf30927834

Passed Non-regression LTC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 123492 W: 31426 L: 31309 D: 60757
Ptnml(0-2): 79, 13705, 34051, 13842, 69
https://tests.stockfishchess.org/tests/view/6782b07e6ddf09c0b4b6dbb7

closes https://github.com/official-stockfish/Stockfish/pull/5761

Bench: 1180439
 2025-01-12 21:23:29 +01:00
Shawn XuandDisservin 8d517bddff Simplify accumulator updates 
AMD Ryzen 5 7600X
```
sf_base =  1902646 +/-   2114 (95%)
sf_test =  1920873 +/-   2515 (95%)
diff    =    18227 +/-   3067 (95%)
speedup = 0.95800% +/- 0.161% (95%)
```

Ryzen 9 5950X
```
sf_base =  1413387 +/-   3592 (95%)
sf_test =  1437893 +/-   3355 (95%)
diff    =    24505 +/-   4669 (95%)
speedup = 1.73380% +/- 0.330% (95%)
```

Intel Core i7-6700K
```
sf_base =   912476 +/-   1863 (95%)
sf_test =   921864 +/-   2042 (95%)
diff    =     9388 +/-   3333 (95%)
speedup = 1.02893% +/- 0.365% (95%)
```

Raspberry Pi 5
```
sf_base =   260993 +/-   1508 (95%)
sf_test =   262912 +/-   1746 (95%)
diff    =     1918 +/-   1221 (95%)
speedup = 0.73504% +/- 0.468% (95%)
```

Passed Non-regression STC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 23072 W: 6041 L: 5813 D: 11218
Ptnml(0-2): 61, 2435, 6319, 2657, 64
https://tests.stockfishchess.org/tests/view/6780a0ca9168c8bf30927757

closes https://github.com/official-stockfish/Stockfish/pull/5759

No functional change
 2025-01-12 21:21:53 +01:00
Shawn XuandDisservin 28c07fb456 Simplify Probcut Condition 
Rebased and properly guarded #5720

Passed Non-regression STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 179616 W: 45764 L: 45706 D: 88146
Ptnml(0-2): 125, 19665, 50162, 19739, 117
https://tests.stockfishchess.org/tests/view/677590531a2f267f20548b82

Passed Non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 445728 W: 113467 L: 113682 D: 218579
Ptnml(0-2): 331, 49226, 123900, 49141, 266
https://tests.stockfishchess.org/tests/view/67734f351a2f267f205489d9

closes https://github.com/official-stockfish/Stockfish/pull/5758

Bench: 1180421
 2025-01-12 21:18:39 +01:00
Shawn XuandDisservin 403a5e100b Simplify Fail-Low Bonus 
Passed Non-regression STC:
LLR: 2.92 (-2.94,2.94) <-1.75,0.25>
Total: 66592 W: 17426 L: 17239 D: 31927
Ptnml(0-2): 208, 7812, 17109, 7919, 248
https://tests.stockfishchess.org/tests/view/6774e1711a2f267f20548b22

Passed Non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 179616 W: 45764 L: 45706 D: 88146
Ptnml(0-2): 125, 19665, 50162, 19739, 117
https://tests.stockfishchess.org/tests/view/677590531a2f267f20548b82

closes https://github.com/official-stockfish/Stockfish/pull/5751

Bench: 1310158
 2025-01-12 21:14:11 +01:00
Shawn XuandDisservin 5370c3035e Refactor Stats Array 
* Limit use of `StatsEntry` wrapper to arithmetic types
* Generalize `Stats` to `MultiArray` by discarding the template parameter `D`
* Allow `MultiArray::fill` to take any type assignable to element type
* Remove now-unused operator overloads on `StatsEntry`

closes https://github.com/official-stockfish/Stockfish/pull/5750

No functional change
 2025-01-12 21:13:14 +01:00
Shawn XuandDisservin c47e6fcf84 Small cleanup of nnue_feature_transformer.h 
Passed Non-regression STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 285760 W: 73716 L: 73768 D: 138276
Ptnml(0-2): 777, 30775, 79851, 30677, 800
https://tests.stockfishchess.org/tests/view/676f78681a2f267f205485aa

closes https://github.com/official-stockfish/Stockfish/pull/5745

No functional change
 2025-01-12 21:11:59 +01:00
Shawn XuandDisservin d1a1ff4f17 Simplify Razoring 
Passed Non-regression STC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 95584 W: 24906 L: 24750 D: 45928
Ptnml(0-2): 285, 11227, 24632, 11343, 305
https://tests.stockfishchess.org/tests/view/675e0ed286d5ee47d95429ee

Passed Non-regression LTC:
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 191292 W: 48637 L: 48589 D: 94066
Ptnml(0-2): 97, 21061, 53276, 21121, 91
https://tests.stockfishchess.org/tests/view/675f08c686d5ee47d9542be3

closes https://github.com/official-stockfish/Stockfish/pull/5724

Bench: 1286274
 2025-01-12 21:11:27 +01:00
Shawn XuandDisservin 5488dd2f91 Update Copyright Year 
closes https://github.com/official-stockfish/Stockfish/pull/5747

No functional change
 2025-01-06 00:45:28 +01:00
Shawn XuandDisservin 00da3ff463 Cleanup stats entry 
Prevents potential issue caused by publicly inheriting from STL container types

closes https://github.com/official-stockfish/Stockfish/pull/5746

No functional change
 2025-01-06 00:44:25 +01:00
Shawn XuandDisservin 5cf6f99177 Remove some incorrectly marked const qualifiers 
closes https://github.com/official-stockfish/Stockfish/pull/5744

No functional change
 2025-01-06 00:43:49 +01:00
Shawn XuandDisservin 78b5733939 Simplify post-lmr conthist bonus 
Passed Non-regression STC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 49184 W: 12735 L: 12528 D: 23921
Ptnml(0-2): 134, 5746, 12647, 5909, 156
https://tests.stockfishchess.org/tests/view/6765cd2e86d5ee47d954420e

Passed Non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 177270 W: 45227 L: 45166 D: 86877
Ptnml(0-2): 132, 19498, 49302, 19583, 120
https://tests.stockfishchess.org/tests/view/676721fd86d5ee47d9544489

closes https://github.com/official-stockfish/Stockfish/pull/5734

Bench: 1042099
 2025-01-06 00:43:37 +01:00
Shawn XuandDisservin e7e78aa09e Adjust LMR with correction history 
A positive constant increase in base reduction is applied to counter the
decrease in average reduction from this tweak.

Passed STC:
LLR: 2.98 (-2.94,2.94) <0.00,2.00>
Total: 109216 W: 28415 L: 27989 D: 52812
Ptnml(0-2): 310, 12848, 27911, 13184, 355
https://tests.stockfishchess.org/tests/view/6760bb0e86d5ee47d9542f26

Passed LTC:
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 66918 W: 17073 L: 16694 D: 33151
Ptnml(0-2): 33, 7175, 18666, 7550, 35
https://tests.stockfishchess.org/tests/view/6761e10f86d5ee47d95431fa

closes https://github.com/official-stockfish/Stockfish/pull/5727

Bench: 1294909
 2024-12-22 15:26:39 +01:00
Shawn XuandDisservin 6075e787d0 Add CI test with glibcxx assertions enabled 
Re: https://github.com/official-stockfish/Stockfish/pull/5721#pullrequestreview-2504542601

closes https://github.com/official-stockfish/Stockfish/pull/5723

No functional change
 2024-12-22 15:20:25 +01:00
Shawn XuandDisservin 77ec878ffa Prevent out of bounds access of dbg info arrays 
closes https://github.com/official-stockfish/Stockfish/pull/5721

No functional change
 2024-12-22 15:19:13 +01:00
Shawn XuandDisservin e770b55f7f Remove Extraneous Parenthesis 
No longer needed after
https://github.com/official-stockfish/Stockfish/pull/5667.

closes https://github.com/official-stockfish/Stockfish/pull/5717

No functional change
 2024-12-22 15:17:33 +01:00
Shawn XuandDisservin b822fdf2f2 Tune histories 
Passed STC:
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 268736 W: 70080 L: 69421 D: 129235
Ptnml(0-2): 831, 31795, 68460, 32448, 834
https://tests.stockfishchess.org/tests/view/6750778886d5ee47d9540e7c

Passed LTC:
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 505356 W: 129145 L: 127868 D: 248343
Ptnml(0-2): 307, 54901, 140959, 56230, 281
https://tests.stockfishchess.org/tests/view/675367de86d5ee47d9541536

closes https://github.com/official-stockfish/Stockfish/pull/5712

Bench: 1148169
 2024-12-22 15:14:22 +01:00
Shawn XuandDisservin 6a8478c6ad Simplify Prior Capture Countermove Bonus 
Passed Non-regression STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 184032 W: 47626 L: 47568 D: 88838
Ptnml(0-2): 590, 21808, 47238, 21714, 666
https://tests.stockfishchess.org/tests/view/67412c7686d5ee47d953f743

Passed Non-regression LTC:
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 169218 W: 43395 L: 43323 D: 82500
Ptnml(0-2): 302, 18567, 46791, 18655, 294
https://tests.stockfishchess.org/tests/view/6743b7e086d5ee47d953f9a6

closes https://github.com/official-stockfish/Stockfish/pull/5701

Bench: 1130692
 2024-12-08 19:55:10 +01:00
Shawn XuandDisservin b7f17346e5 Fix Sanitizer Tests 
closes https://github.com/official-stockfish/Stockfish/pull/5692

No functional change
 2024-11-22 23:41:34 +01:00
Shawn XuandDisservin 4fcd78ceb4 Simplify Probcut Bonus 
Passed STC:
LLR: 2.99 (-2.94,2.94) <-1.75,0.25>
Total: 172288 W: 44656 L: 44580 D: 83052
Ptnml(0-2): 507, 20650, 43782, 20670, 535
https://tests.stockfishchess.org/tests/view/673b74f986d5ee47d953f1a3

Passed LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 94596 W: 24098 L: 23953 D: 46545
Ptnml(0-2): 57, 10322, 26393, 10471, 55
https://tests.stockfishchess.org/tests/view/673d191886d5ee47d953f337

closes https://github.com/official-stockfish/Stockfish/pull/5688

Bench: 1031022
 2024-11-22 23:31:34 +01:00
Shawn XuandDisservin cc5c67c564 Introduce Fractional LMR 
Tuning Run (90k Games):
https://tests.stockfishchess.org/tests/view/67202b1c86d5ee47d953d442

Passed STC:
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 241024 W: 62616 L: 62001 D: 116407
Ptnml(0-2): 716, 28231, 62015, 28822, 728
https://tests.stockfishchess.org/tests/view/6725196786d5ee47d953d9f2

Passed LTC:
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 92532 W: 23678 L: 23246 D: 45608
Ptnml(0-2): 45, 9981, 25797, 10383, 60
https://tests.stockfishchess.org/tests/view/6727d3cb86d5ee47d953db9d

closes https://github.com/official-stockfish/Stockfish/pull/5667

Bench: 1066071
 2024-11-13 20:12:47 +01:00
Shawn XuandDisservin c2611efe5c Move history code to a separate header 
Since no correction histories are ever used inside Movepick, and many
existing histories are closely integrated into search, it might be more
logical to separate them into their own header. PR based on #5650

closes https://github.com/official-stockfish/Stockfish/pull/5652

No functional change
 2024-11-13 20:07:15 +01:00
Shawn XuandDisservin 4a9c980f3b Template Corrhist 
Avoids duplication of `using ... = Stats<int16_t,
CORRECTION_HISTORY_LIMIT, COLOR_NB, CORRECTION_HISTORY_SIZE>;`

closes https://github.com/official-stockfish/Stockfish/pull/5650

No functional change

Co-authored-by: Disservin <disservin.social@gmail.com>
 2024-10-31 09:27:12 +01:00
Shawn XuandDisservin b261df970d Fix majorPieceKey Updates 
Passed STC:
LLR: 2.98 (-2.94,2.94) <0.00,2.00>
Total: 476160 W: 124285 L: 123311 D: 228564
Ptnml(0-2): 1662, 56266, 121219, 57302, 1631
https://tests.stockfishchess.org/tests/view/66ea3dc186d5ee47d953ae07

Failed Yellow LTC:
LLR: -2.94 (-2.94,2.94) <0.50,2.50>
Total: 230634 W: 58525 L: 58295 D: 113814
Ptnml(0-2): 113, 25301, 64299, 25451, 153
https://tests.stockfishchess.org/tests/view/66f1825e86d5ee47d953b2ec

Passed Non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 112344 W: 28590 L: 28462 D: 55292
Ptnml(0-2): 71, 12439, 31039, 12537, 86
https://tests.stockfishchess.org/tests/view/6707474486d5ee47d953bfe3

closes https://github.com/official-stockfish/Stockfish/pull/5629

Bench: 1283457
 2024-10-12 16:40:49 +02:00
Shawn XuandJoost VandeVondele d6043970bd Make Correction History Size Uniform 
Passed Non-regression STC:
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 207232 W: 53834 L: 53802 D: 99596
Ptnml(0-2): 695, 24486, 53200, 24562, 673
https://tests.stockfishchess.org/tests/view/66e9f5a886d5ee47d953ada1

Passed Non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 99120 W: 25264 L: 25123 D: 48733
Ptnml(0-2): 66, 10803, 27675, 10956, 60
https://tests.stockfishchess.org/tests/view/66ed7ebc86d5ee47d953b056

Passed Non-regression LTC vs #5606:
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 208950 W: 53049 L: 53019 D: 102882
Ptnml(0-2): 111, 23232, 57760, 23260, 112
https://tests.stockfishchess.org/tests/view/66f1843886d5ee47d953b2f2

closes https://github.com/official-stockfish/Stockfish/pull/5609

bench 1575189
 2024-09-28 18:01:31 +02:00
Shawn XuandDisservin 60351b9df9 Introduce Various Correction histories 
This patch introduces three additional correction histories, namely,
Major Piece Correction History, Minor Piece Correction History, and
Non-Pawn Correction History.

Introduced by @mcthouacbb in Sirius
(https://github.com/mcthouacbb/Sirius) chess engine. The Major Piece
Correction History is indexed by side-to-move and the Zobrist key
representing the position of the King, Rook, and Queen of both sides.
Likewise, the Minor Piece Correction History is indexed by side-to-move
and the Zobrist key representing the position of the King, Knight, and
Bishop of both sides.

Also See:
https://github.com/mcthouacbb/Sirius/commit/97b85bbaac88ff5a0f63e28776027dd3de77164e
https://github.com/mcthouacbb/Sirius/commit/3099cdef2f13e29805654b5f8153e6ecd5853195

Introduced by @zzzzz151 in Starzix (https://github.com/zzzzz151/Starzix)
chess engine. Non-Pawn correction history consists of side-to-move, side
of Zobrist key, and a Zobrist key representing of the position of all
non-pawn pieces of **one side**. The non-pawn correction values for both
key sides are then summed.

Also See:
https://github.com/zzzzz151/Starzix/commit/34911772f178c27b3a239dda0acb79c397c3a2f0
https://github.com/zzzzz151/Starzix/commit/33e0df8dd2db1d4775974ab12e3390154697f47a

The weights on the final correction value of the above correction
histories, as well as existing correction histories, are then tuned in
two separate SPSA sessions, totaling 75k games.

SPSA1:
https://tests.stockfishchess.org/tests/view/66e5243886d5ee47d953a86b
(Stopped early due to some weights reaching the maximum value)

SPSA2:
https://tests.stockfishchess.org/tests/view/66e6a26f86d5ee47d953a965

Also thanks to @martinnovaak, (Motor
https://github.com/martinnovaak/motor author) for insights and
suggestions.

Passed STC:
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 23328 W: 6197 L: 5901 D: 11230
Ptnml(0-2): 82, 2582, 6041, 2876, 83
https://tests.stockfishchess.org/tests/view/66e8787b86d5ee47d953ab6f

Passed LTC:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 10626 W: 2826 L: 2560 D: 5240
Ptnml(0-2): 4, 1054, 2941, 1300, 14
https://tests.stockfishchess.org/tests/view/66e8ab2386d5ee47d953aba8

closes https://github.com/official-stockfish/Stockfish/pull/5598

Bench: 1011161
 2024-09-17 21:01:43 +02:00
Shawn XuandDisservin 5ce7f866a5 Simplify Fail Low Bonus 
Passed Non-regression STC:
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 302528 W: 78190 L: 78264 D: 146074
Ptnml(0-2): 1029, 35797, 77551, 35993, 894
https://tests.stockfishchess.org/tests/view/66dcebdedc53972b68218c7e

Passed Non-regression LTC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 122754 W: 31025 L: 30907 D: 60822
Ptnml(0-2): 74, 13597, 33908, 13733, 65
https://tests.stockfishchess.org/tests/view/66e0c38686d5ee47d953a481

closes https://github.com/official-stockfish/Stockfish/pull/5594

Bench: 1646373
 2024-09-17 20:50:30 +02:00
Shawn XuandDisservin ddc9f48bc3 Introduce Material Correction History 
Idea from Caissa (https://github.com/Witek902/Caissa) chess engine.

Add a secondary correction history indexed by the material key of a position.
The material key is the zobrist hash representing the number of pieces left in a
position.

Passed STC:
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 189472 W: 49360 L: 48813 D: 91299
Ptnml(0-2): 666, 22453, 47953, 22996, 668
https://tests.stockfishchess.org/tests/view/66cbddafbf8c9d8780fda9f1

Passed LTC:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 224190 W: 57022 L: 56312 D: 110856
Ptnml(0-2): 197, 24723, 61540, 25443, 192
https://tests.stockfishchess.org/tests/view/66cd529bbf8c9d8780fdab4c

closes https://github.com/official-stockfish/Stockfish/pull/5556

Bench: 1462697
 2024-09-09 17:43:05 +02:00
Shawn XuandJoost VandeVondele d275bf9643 Introduce Fail Low History Bonus 
When a node fails low, give TT move a small bonus 1/4 of normal value.

Passed STC:
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 92384 W: 24094 L: 23691 D: 44599
Ptnml(0-2): 323, 10852, 23465, 11203, 349
https://tests.stockfishchess.org/tests/view/66be80794ff211be9d4eed68

Passed LTC:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 114660 W: 29260 L: 28778 D: 56622
Ptnml(0-2): 97, 12506, 31653, 12966, 108
https://tests.stockfishchess.org/tests/view/66bf63ee4ff211be9d4eeef0

closes https://github.com/official-stockfish/Stockfish/pull/5539

bench 1463003
 2024-08-20 21:34:19 +02:00
Shawn XuandJoost VandeVondele 87814d2fb8 Simplify doShallowerSearch 
Passed Non-regression STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 242336 W: 62657 L: 62663 D: 117016
Ptnml(0-2): 941, 28949, 61418, 28895, 965
https://tests.stockfishchess.org/tests/view/66bc13c34ff211be9d4ee794

Passed Non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 128100 W: 32503 L: 32390 D: 63207
Ptnml(0-2): 106, 14319, 35113, 14380, 132
https://tests.stockfishchess.org/tests/view/66bdbb304ff211be9d4eec5d

closes https://github.com/official-stockfish/Stockfish/pull/5537

bench 1586246
 2024-08-20 21:27:58 +02:00
Shawn XuandJoost VandeVondele 175021721c Simplify bestMove promotion 
Passed Non-regression STC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 216768 W: 56240 L: 56217 D: 104311
Ptnml(0-2): 794, 24900, 56956, 24957, 777
https://tests.stockfishchess.org/tests/view/66bc11324ff211be9d4ee78b

Passed Non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 44970 W: 11391 L: 11199 D: 22380
Ptnml(0-2): 44, 4596, 13002, 4810, 33
https://tests.stockfishchess.org/tests/view/66bdbb1b4ff211be9d4eec5a

closes https://github.com/official-stockfish/Stockfish/pull/5535

bench: 1613043
 2024-08-20 21:24:04 +02:00
Shawn XuandJoost VandeVondele a75717ede1 Simplify Post-LMR Continuation History Updates 
Passed Non-regression STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 55520 W: 14625 L: 14420 D: 26475
Ptnml(0-2): 247, 6522, 14007, 6747, 237
https://tests.stockfishchess.org/tests/view/66ad40874ff211be9d4ed8f7

Passed Non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 216168 W: 54561 L: 54540 D: 107067
Ptnml(0-2): 196, 24212, 59244, 24239, 193
https://tests.stockfishchess.org/tests/view/66aeac954ff211be9d4eda03

closes https://github.com/official-stockfish/Stockfish/pull/5530

bench 1418263
 2024-08-20 20:51:39 +02:00
Shawn XuandJoost VandeVondele bc80ece6c7 Improve Comments for Pairwise Multiplication Optimization 
closes https://github.com/official-stockfish/Stockfish/pull/5524

no functional change
 2024-08-20 20:47:46 +02:00
Shawn XuandJoost VandeVondele ae9e55cf53 Simplify Cutnode Reduction 
Passed Non-regression STC:
LR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 143968 W: 37439 L: 37333 D: 69196
Ptnml(0-2): 521, 17228, 36456, 17182, 597
https://tests.stockfishchess.org/tests/view/66a73f9f4ff211be9d4ed27f

Passed Non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 198954 W: 50384 L: 50345 D: 98225
Ptnml(0-2): 201, 22360, 54347, 22337, 232
https://tests.stockfishchess.org/tests/view/66a906e94ff211be9d4ed423

closes https://github.com/official-stockfish/Stockfish/pull/5526

bench 1277466
 2024-08-03 09:42:54 +02:00
Shawn XuandDisservin 2343f71f3f Remove Killers 
The removal of killers on line 1774 resulted in a substantial decrease
in pre-LMR history average, so a negative history fill is applied to
counter it.

Passed Non-regression STC (vs #5513):
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 21984 W: 5886 L: 5645 D: 10453
Ptnml(0-2): 80, 2492, 5628, 2691, 101
https://tests.stockfishchess.org/tests/view/66a095894ff211be9d4ecb9d

Passed Non-regression LTC (vs #5513):
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 95430 W: 24141 L: 23995 D: 47294
Ptnml(0-2): 97, 10537, 26298, 10689, 94
https://tests.stockfishchess.org/tests/view/66a11c8d4ff211be9d4ecbf8

closes https://github.com/official-stockfish/Stockfish/pull/5517

Bench: 1660869
 2024-07-28 22:22:50 +02:00