81c1d31084
Decrease probCutBeta based on opponentWorsening
...
Passed STC:
LLR: 2.97 (-2.94,2.94) <0.00,2.00>
Total: 62112 W: 16305 L: 15947 D: 29860
Ptnml(0-2): 203, 7226, 15856, 7552, 219
https://tests.stockfishchess.org/tests/view/66f85fc986d5ee47d953b71e
Passed LTC:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 129552 W: 33223 L: 32710 D: 63619
Ptnml(0-2): 94, 14250, 35573, 14767, 92
https://tests.stockfishchess.org/tests/view/66f93fef86d5ee47d953b7d2
closes https://github.com/official-stockfish/Stockfish/pull/5615
bench: 1511354
2024-10-04 08:35:08 +02:00
7ac745a736
Refactor root history into low ply history
...
This patch changes root history to low ply history - butterfly history for plies < 4.
Doubles weight of this history for root, latter plies have lesser effect.
Passed STC:
https://tests.stockfishchess.org/tests/view/66f77d2386d5ee47d953b65d
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 180992 W: 47362 L: 46830 D: 86800
Ptnml(0-2): 554, 21499, 45928, 21891, 624
Passed LTC:
https://tests.stockfishchess.org/tests/view/66fb557986d5ee47d953b8e5
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 42462 W: 11013 L: 10682 D: 20767
Ptnml(0-2): 33, 4518, 11795, 4855, 30
closes https://github.com/official-stockfish/Stockfish/pull/5614
Bench 1264335
2024-10-04 08:32:21 +02:00
c85f802185
Tweak ttCapture reduction
...
More reduction at shallow depth for quiet moves when ttMove is a capture.
Passed STC:
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 365728 W: 95896 L: 95090 D: 174742
Ptnml(0-2): 1283, 43133, 93262, 43867, 1319
https://tests.stockfishchess.org/tests/view/66edd35986d5ee47d953b0d5
Passed LTC:
LLR: 2.96 (-2.94,2.94) <0.50,2.50>
Total: 200526 W: 51197 L: 50540 D: 98789
Ptnml(0-2): 119, 21952, 55462, 22613, 117
https://tests.stockfishchess.org/tests/view/66f405dc86d5ee47d953b460
closes https://github.com/official-stockfish/Stockfish/pull/5610
bench: 1269487
2024-10-01 20:59:17 +02:00
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
56444ce1f7
Push expected cutting late moves up in the move ordering.
...
since the passing of the LMR verification is coming from a relatively late move
this means we have wasted some time trying/picking other moves, and it would
make sense to push it up in the move ordering for future positions not to be as
late.
Passed STC:
https://tests.stockfishchess.org/tests/view/66f0f69186d5ee47d953b2aa
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 34144 W: 9024 L: 8709 D: 16411
Ptnml(0-2): 137, 3875, 8732, 4192, 136
Passed LTC:
https://tests.stockfishchess.org/tests/view/66f1d84a86d5ee47d953b325
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 62808 W: 16054 L: 15684 D: 31070
Ptnml(0-2): 24, 6725, 17555, 7057, 43
closes https://github.com/official-stockfish/Stockfish/pull/5608
bench: 1452807
2024-09-28 18:01:31 +02:00
aff1f67997
simplify see pruning in qsearch
...
passed non-regression STC:
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 34880 W: 9193 L: 8968 D: 16719
Ptnml(0-2): 103, 4047, 8935, 4232, 123
https://tests.stockfishchess.org/tests/view/66ee83bd86d5ee47d953b15b
passed non-regression LTC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 69126 W: 17529 L: 17357 D: 34240
Ptnml(0-2): 41, 7507, 19285, 7699, 31
https://tests.stockfishchess.org/tests/view/66ef3e0386d5ee47d953b1d3
closes https://github.com/official-stockfish/Stockfish/pull/5607
Bench: 1339840
2024-09-28 17:22:33 +02:00
ae420e735f
Tweak Correction histories
...
tune parameters some more, adjust scores updated for each history
passed STC:
https://tests.stockfishchess.org/tests/view/66ea569186d5ee47d953ae48
LLR: 2.92 (-2.94,2.94) <0.00,2.00>
Total: 36288 W: 9660 L: 9344 D: 17284
Ptnml(0-2): 110, 4207, 9220, 4471, 136
passed LTC:
https://tests.stockfishchess.org/tests/view/66ea9b4e86d5ee47d953ae6f
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 241446 W: 61748 L: 61010 D: 118688
Ptnml(0-2): 173, 26211, 67202, 26979, 158
closes https://github.com/official-stockfish/Stockfish/pull/5606
Bench: 1677953
2024-09-28 17:17:44 +02:00
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
240a5b1c72
Introduce separate butterfly history table for sorting root moves
...
Idea of this patch comes from the fact that current history heuristics
are mostly populated by low depth entries since our stat bonus reaches
maximum value at depth 5-6 and number of low depth nodes is much bigger
than number of high depth nodes. But it doesn't make a whole lost of
sense to use this low-depth centered histories to sort moves at root.
Current patch introduces special history table that is used exclusively
at root, it remembers which quiet moves were good and which quiet moves
were not good there and uses this information for move ordering.
Passed STC:
https://tests.stockfishchess.org/tests/view/66dda74adc53972b68218cc9
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 127680 W: 33579 L: 33126 D: 60975
Ptnml(0-2): 422, 15098, 32391, 15463, 466
Passed LTC:
https://tests.stockfishchess.org/tests/view/66dead2adc53972b68218d34
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 381978 W: 96958 L: 95923 D: 189097
Ptnml(0-2): 277, 42165, 105089, 43162, 296
closes https://github.com/official-stockfish/Stockfish/pull/5595
Bench: 1611283
2024-09-17 20:54:02 +02:00
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
224c147bd6
VVLTC Search Tune
...
Tuned with 115k games at VVLTC:
https://tests.stockfishchess.org/tests/view/66c80e09bf8c9d8780fda62a
Passed VVLTC 1st sprt:
https://tests.stockfishchess.org/tests/view/66d69ade9de3e7f9b33d14f9
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 54270 W: 13935 L: 13647 D: 26688
Ptnml(0-2): 2, 4907, 17032, 5189, 5
Passed VVLTC 2nd sprt:
https://tests.stockfishchess.org/tests/view/66dcf9c1dc53972b68218c84
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 136696 W: 34941 L: 34462 D: 67293
Ptnml(0-2): 8, 12659, 42535, 13138, 8
closes https://github.com/official-stockfish/Stockfish/pull/5592
Bench: 1644273
2024-09-17 20:47:24 +02:00
d8e49cdbdd
Remove the moveCount increase in the LMR condition.
...
Passed non-regression STC:
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 87104 W: 22630 L: 22464 D: 42010
Ptnml(0-2): 316, 10295, 22132, 10525, 284
https://tests.stockfishchess.org/tests/view/66dccd00dc53972b68218c60
Passed non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 94050 W: 23869 L: 23722 D: 46459
Ptnml(0-2): 49, 10400, 25985, 10537, 54
https://tests.stockfishchess.org/tests/view/66dd69c7dc53972b68218ca5
closes https://github.com/official-stockfish/Stockfish/pull/5582
Bench: 1281840
2024-09-10 22:59:27 +02:00
6de2587236
Remove statScore condition in NMP
...
Eliminate the condition that is nearly 100% likelihood of being true.
Passed non-regression STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 208832 W: 54053 L: 54022 D: 100757
Ptnml(0-2): 753, 24987, 52901, 25026, 749
https://tests.stockfishchess.org/tests/view/66cddb50bf8c9d8780fdabaf
Passed non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 154344 W: 39132 L: 39047 D: 76165
Ptnml(0-2): 115, 17231, 42403, 17300, 123
https://tests.stockfishchess.org/tests/view/66cfafe39de3e7f9b33d1050
closes https://github.com/official-stockfish/Stockfish/pull/5558
Bench: 1393697
2024-09-10 22:58:47 +02:00
a8cb002038
Simplify ttmove reduction
...
Remove condition that clamps reductions for tt move.
Passed STC:
https://tests.stockfishchess.org/tests/view/66d5f1239de3e7f9b33d14b0
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 91136 W: 23805 L: 23646 D: 43685
Ptnml(0-2): 334, 10328, 24066, 10525, 315
Passed LTC:
https://tests.stockfishchess.org/tests/view/66d7c5889de3e7f9b33d1721
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 139242 W: 35130 L: 35030 D: 69082
Ptnml(0-2): 78, 15200, 38986, 15258, 99
closes https://github.com/official-stockfish/Stockfish/pull/5574
Bench: 1268715
2024-09-09 18:02:32 +02:00
e74452ae44
Reduce on ttcaptures if not capture
...
Tweak ttcapture reduction.
Reduce on ttcaptures only if the current move is a capture
Passed STC:
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 94912 W: 24896 L: 24492 D: 45524
Ptnml(0-2): 301, 11197, 24087, 11539, 332
https://tests.stockfishchess.org/tests/view/66cd2264bf8c9d8780fdab34
Passed LTC:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 60738 W: 15465 L: 15096 D: 30177
Ptnml(0-2): 42, 6573, 16775, 6932, 47
https://tests.stockfishchess.org/tests/view/66cf356d9de3e7f9b33d0fde
closes https://github.com/official-stockfish/Stockfish/pull/5562
Bench: 1268700
2024-09-09 17:48:26 +02:00
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
4fb04eb3df
Simplify history bonus
...
After we recently added the disallowance for negative bonuses, it is no
longer necessary to keep the max comparison in the previous step.
Passed STC:
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 72000 W: 18820 L: 18637 D: 34543
Ptnml(0-2): 267, 8489, 18276, 8730, 238
https://tests.stockfishchess.org/tests/view/66ce132cbf8c9d8780fdabe7
Passed LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 67452 W: 17136 L: 16961 D: 33355
Ptnml(0-2): 35, 7489, 18519, 7632, 51
https://tests.stockfishchess.org/tests/view/66cf6ad49de3e7f9b33d1010
closes https://github.com/official-stockfish/Stockfish/pull/5554
Bench: 1147012
2024-09-09 17:34:31 +02:00
451044202a
Simpler formula for ss->cutoffCnt update
...
closes https://github.com/official-stockfish/Stockfish/pull/5548
No functional change
2024-08-28 09:35:21 +02:00
54def6f7eb
rename !(PvNode || cutNode) to allNode
...
Passed STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 108992 W: 28178 L: 28039 D: 52775
Ptnml(0-2): 356, 12428, 28762, 12621, 329
https://tests.stockfishchess.org/tests/view/66c73a51bf8c9d8780fda532
closes https://github.com/official-stockfish/Stockfish/pull/5549
No functional change
2024-08-28 09:34:09 +02:00
9fb58328e3
Tweak late move extensions
...
Allow late move extensions only for PV and cut nodes.
Passed STC:
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 44512 W: 11688 L: 11355 D: 21469
Ptnml(0-2): 167, 5180, 11229, 5513, 167
https://tests.stockfishchess.org/tests/view/66c0509d4ff211be9d4ef10e
Passed LTC:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 152970 W: 39026 L: 38466 D: 75478
Ptnml(0-2): 102, 16792, 42164, 17298, 129
https://tests.stockfishchess.org/tests/view/66c0994d21503a509c13b2b6
closes https://github.com/official-stockfish/Stockfish/pull/5541
bench: 1484730
2024-08-20 21:37:25 +02:00
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
6cf7f300ac
Simplify stand pat adjustement
...
Remove && !PvNode condition for stand pat adjustement in quiescence search.
Passed non-regression STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 108544 W: 28228 L: 28085 D: 52231
Ptnml(0-2): 389, 12902, 27554, 13031, 396
https://tests.stockfishchess.org/tests/view/66bb402e4ff211be9d4ee688
Passed non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 193014 W: 48796 L: 48751 D: 95467
Ptnml(0-2): 188, 21481, 53116, 21542, 180
https://tests.stockfishchess.org/tests/view/66bc78774ff211be9d4ee88f
closes https://github.com/official-stockfish/Stockfish/pull/5538
Bench 1787360
2024-08-20 21:31:33 +02:00
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
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
4995792a6c
Simplify cutnode reduction formula
...
Passed STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 137994 W: 34705 L: 34603 D: 68686
Ptnml(0-2): 124, 15371, 37903, 15477, 122
https://tests.stockfishchess.org/tests/view/66aeb74b4ff211be9d4eda10
Passed LTC:
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 131456 W: 34148 L: 34031 D: 63277
Ptnml(0-2): 506, 15571, 33465, 15672, 514
https://tests.stockfishchess.org/tests/view/66ae258b4ff211be9d4ed95d
closes https://github.com/official-stockfish/Stockfish/pull/5531
Bench: 1261995
2024-08-20 20:57:07 +02:00
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
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
8e560c4fd3
Replicate network weights only to used NUMA nodes
...
On a system with multiple NUMA nodes, this patch avoids unneeded replicated
(e.g. 8x for a single threaded run), reducting memory use in that case.
Lazy initialization forced before search.
Passed STC:
https://tests.stockfishchess.org/tests/view/66a28c524ff211be9d4ecdd4
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 691776 W: 179429 L: 179927 D: 332420
Ptnml(0-2): 2573, 79370, 182547, 78778, 2620
closes https://github.com/official-stockfish/Stockfish/pull/5515
No functional change
2024-08-03 09:41:37 +02:00
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
af802da65b
Clean up comments for movepicker
...
Remove references to checks in MovePicker comments. Follow-up for
https://github.com/official-stockfish/Stockfish/pull/5498
closes https://github.com/official-stockfish/Stockfish/pull/5516
No functional change
2024-07-28 22:21:03 +02:00
607c3e404f
Remove unneeded depth tracking in qsearch
...
Since simplification of quiet checks in qsearch this depth isn't used by
any function at all apart movepicker, which also doesn't use passed
qsearch depth in any way, so can be removed. No functional change.
closes https://github.com/official-stockfish/Stockfish/pull/5514
No functional change
2024-07-28 22:18:33 +02:00
85893ac1cd
Simplify Away Killer Condition in Cutnode LMR
...
Passed Non-regression STC:
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 42944 W: 11240 L: 11024 D: 20680
Ptnml(0-2): 159, 5056, 10825, 5274, 158
https://tests.stockfishchess.org/tests/view/669c13384ff211be9d4ec69f
Passed Non-regression LTC:
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 163548 W: 41366 L: 41289 D: 80893
Ptnml(0-2): 109, 18246, 45007, 18283, 129
https://tests.stockfishchess.org/tests/view/669cb1254ff211be9d4ec73a
closes https://github.com/official-stockfish/Stockfish/pull/5513
Bench: 1178570
2024-07-28 22:13:47 +02:00
836154acb5
Introduce pre-qsearch ttmove extensions at pv nodes
...
The idea is that we are about to dive into qsearch (next search depth is <= 0)
but since we have the move in transposition table we should extend that move
and evaluate it with more precise search - because branch seems important.
Passed STC:
https://tests.stockfishchess.org/tests/view/6699d2564ff211be9d4ec488
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 83104 W: 21789 L: 21401 D: 39914
Ptnml(0-2): 293, 9748, 21128, 10044, 339
Passed LTC:
https://tests.stockfishchess.org/tests/view/669b3f1a4ff211be9d4ec602
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 136098 W: 34636 L: 34111 D: 67351
Ptnml(0-2): 105, 14882, 37550, 15407, 105
closes https://github.com/official-stockfish/Stockfish/pull/5512
bench 1526129
2024-07-23 19:24:00 +02:00
985b9fd7b0
Remove Killer Heuristic In Move Ordering
...
Passed Non-regression STC:
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 80480 W: 20979 L: 20802 D: 38699
Ptnml(0-2): 279, 9610, 20337, 9683, 331
https://tests.stockfishchess.org/tests/view/669c12c14ff211be9d4ec69b
Passed Non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 77988 W: 19788 L: 19624 D: 38576
Ptnml(0-2): 66, 8605, 21481, 8783, 59
https://tests.stockfishchess.org/tests/view/669d628a4ff211be9d4ec7a8
closes https://github.com/official-stockfish/Stockfish/pull/5511
bench 1367740
2024-07-23 19:24:00 +02:00
bb4b01e306
Fix TB guard
...
even if beta is below TB range, once we return probcutBeta with beta + 390 we
can return wrong TB value, and guard against ttData.value being `VALUE_NONE`
closes https://github.com/official-stockfish/Stockfish/pull/5499
bench: 1440277
2024-07-23 19:24:00 +02:00
986173264f
Adding LowestElo and HighestElo constants
...
These values represent the lowest Elo rating in the skill level calculation,
and the highest one, but it's not clear from the code where these values come
from other than the comment. This should improve code readability and
maintainability. It makes the purpose of the values clear and allows for easy
modification if the Elo range for skill level calculation changes in the
future. Moved the Skill struct definition from search.cpp to search.h header
file to define the Search::Skill struct, making it accessible from other files.
closes https://github.com/official-stockfish/Stockfish/pull/5508
No functional change
2024-07-23 19:23:57 +02:00
a2ba3e3362
Bonus Simplification
...
This tune removes completely a recently added term.
Passed STC:
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 61376 W: 16046 L: 15693 D: 29637
Ptnml(0-2): 207, 7132, 15665, 7469, 215
https://tests.stockfishchess.org/tests/view/669512b94ff211be9d4ebffb
Passed LTC:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 100662 W: 25474 L: 25020 D: 50168
Ptnml(0-2): 64, 11092, 27581, 11514, 80
https://tests.stockfishchess.org/tests/view/66955f194ff211be9d4ec06a
Passed LTC#2:
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 28056 W: 7128 L: 6909 D: 14019
Ptnml(0-2): 18, 3084, 7620, 3273, 33
https://tests.stockfishchess.org/tests/view/669a541a4ff211be9d4ec52b
closes https://github.com/official-stockfish/Stockfish/pull/5502
bench: 1619438
2024-07-23 18:01:14 +02:00
703f17975b
Remove QS_CHECKS movepick stage
...
Passed STC: https://tests.stockfishchess.org/tests/view/669597cf4ff211be9d4ec147
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 199072 W: 52100 L: 52058 D: 94914
Ptnml(0-2): 829, 23679, 50406, 23865, 757
Passed LTC: https://tests.stockfishchess.org/tests/view/66988f5f4ff211be9d4ec33e
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 119778 W: 30420 L: 30299 D: 59059
Ptnml(0-2): 106, 13293, 32957, 13440, 93
closes https://github.com/official-stockfish/Stockfish/pull/5498
Bench 1499842
2024-07-23 17:56:52 +02:00
e57fba7fc9
Fix TB PV extension and MultiPV
...
in the case of MultiPV, the first move of the Nth multiPV could actually turn a
winning position in a losing one, so don't attempt to correct it. Instead,
always perform the first move without correction.
Fixes #5505
Closes https://github.com/official-stockfish/Stockfish/pull/5506
No functional change
2024-07-23 17:51:30 +02:00
a8401e803d
Adjust bonus to move that caused a fail low
...
This is an elo gainer and simultaneously a minor logical fix to bonuses that caused a fail low.
It increases maximum of statscore based subtraction - but disallows negative bonuses.
Passed STC:
https://tests.stockfishchess.org/tests/view/66955e6f4ff211be9d4ec063
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 44640 W: 11805 L: 11472 D: 21363
Ptnml(0-2): 166, 5178, 11335, 5439, 202
Passed LTC:
https://tests.stockfishchess.org/tests/view/66963fde4ff211be9d4ec190
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 72288 W: 18478 L: 18082 D: 35728
Ptnml(0-2): 50, 7919, 19825, 8285, 65
closes https://github.com/official-stockfish/Stockfish/pull/5494
Bench: 1477054
2024-07-19 08:41:38 +02:00
c8d8e362fc
Try nullmoves only on cutnodes
...
since master only tries nullmoves on cutNodes already with 99.0224% of the
cases running bench, We can try null moves at 100% of cutNodes and achieve such
simplification, by making passing false already equivalent to passing !cutNode
This is a more correct form of PR #5482
Passed non-regression STC:
https://tests.stockfishchess.org/tests/view/66941c044ff211be9d4ebf5f
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 153216 W: 39856 L: 39764 D: 73596
Ptnml(0-2): 590, 18174, 38979, 18284, 581
Passed non-regression LTC:
https://tests.stockfishchess.org/tests/view/6694e5cd4ff211be9d4ebfdf
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 67842 W: 17178 L: 17004 D: 33660
Ptnml(0-2): 52, 7437, 18759, 7631, 42
closes https://github.com/official-stockfish/Stockfish/pull/5490
bench: 1345400
Co-Authored-By: FauziAkram <11150271+fauziakram@users.noreply.github.com >
2024-07-19 08:38:13 +02:00
27042fe949
Linearize corrHist
...
Passed STC: https://tests.stockfishchess.org/tests/view/66919cdec6827afcdcee146f
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 130656 W: 33579 L: 33461 D: 63616
Ptnml(0-2): 394, 15548, 33318, 15682, 386
Passed VVLTC: https://tests.stockfishchess.org/tests/view/6691acb2c6827afcdcee1645
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 160314 W: 40925 L: 40854 D: 78535
Ptnml(0-2): 12, 14754, 50551, 14831, 9
closes https://github.com/official-stockfish/Stockfish/pull/5489
bench 1380295
2024-07-19 08:36:25 +02:00
7bb45d05fa
Replace ternary with std::min
...
equivalent and more readable.
closes https://github.com/official-stockfish/Stockfish/pull/5488
No functional change
2024-07-19 08:34:02 +02:00
c755bc1a73
Simplify improving condition
...
if we were in check at our previous move we look back until we weren't
in check and take the staticEval of that position as reference.
Passed STC:
https://tests.stockfishchess.org/tests/view/668ba7b65034141ae5996665
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 74784 W: 19454 L: 19274 D: 36056
Ptnml(0-2): 260, 8874, 18952, 9038, 268
Passted LTC:
https://tests.stockfishchess.org/tests/view/668cb2db5034141ae599678b
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 241488 W: 61166 L: 61171 D: 119151
Ptnml(0-2): 190, 27154, 66062, 27147, 191
closes https://github.com/official-stockfish/Stockfish/pull/5492
bench: 1368313
2024-07-19 08:32:16 +02:00
de2bf1a186
Remove quiet history pruning depth limit
...
This patch removes lmrDepth limit for quiet moves history based pruning.
Previously removal of this type of depth limits was considered bad because it
was performing bad for matetrack - but with this pruning heuristic this
shouldn't be that bad because it's "naturally" depth limited by history
threshold and should be completely disabled at depth >= 15 or so. Also this
heuristic in previous years was known to scale non-linearly - bigger lmrDepth
thresholds were better at longer time controls and removing it completely
probably should scale pretty well.
Passed STC:
https://tests.stockfishchess.org/tests/view/6692b89b4ff211be9d4eab21
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 114464 W: 29675 L: 29545 D: 55244
Ptnml(0-2): 372, 12516, 31329, 12640, 375
Passed LTC:
https://tests.stockfishchess.org/tests/view/6692c4554ff211be9d4eab3d
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 67746 W: 17182 L: 17014 D: 33550
Ptnml(0-2): 28, 6993, 19652, 7183, 17
closes https://github.com/official-stockfish/Stockfish/pull/5485
Bench: 1250388
2024-07-15 13:35:06 +02:00
2b37b151dd
Use ValueList to represent searched moves array
...
This PR replaces a pair of array and size with existing ValueList class.
Removes two local variables in search and two parameters of
update_all_stats.
Passed non-regression STC:
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 227040 W: 58472 L: 58463 D: 110105
Ptnml(0-2): 495, 23572, 65427, 23481, 545
https://tests.stockfishchess.org/tests/view/669299204ff211be9d4e98dc
closes https://github.com/official-stockfish/Stockfish/pull/5484
No functional change
2024-07-15 13:30:47 +02:00
7395d56832
bonus calculation for prior countermoves
...
Introduce a new term to the bonus calculation for prior countermoves
Passed STC:
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 140896 W: 36545 L: 36079 D: 68272
Ptnml(0-2): 383, 16505, 36217, 16949, 394
https://tests.stockfishchess.org/tests/view/6691c73cc6827afcdcee1816
Passed LTC:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 126660 W: 32089 L: 31587 D: 62984
Ptnml(0-2): 63, 13774, 35154, 14276, 63
https://tests.stockfishchess.org/tests/view/6691cdc4c6827afcdcee1930
closes https://github.com/official-stockfish/Stockfish/pull/5483
bench: 1250388
2024-07-15 13:27:42 +02:00
558abdbe8a
Set best value to futility value after pruned quiet move
...
Passed non-regression STC:
https://tests.stockfishchess.org/tests/view/6691592f5034141ae599c68d
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 278496 W: 71818 L: 71865 D: 134813
Ptnml(0-2): 865, 33311, 70978, 33194, 900
Passed non-regression LTC:
https://tests.stockfishchess.org/tests/view/66918fca5034141ae599e761
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 202986 W: 51048 L: 51013 D: 100925
Ptnml(0-2): 107, 22552, 56133, 22601, 100
closes https://github.com/official-stockfish/Stockfish/pull/5480
bench 1715206
2024-07-15 13:24:14 +02:00
930915de90
Decrease delta
...
Decrease delta in aspiration windows - both initial value and quadratic
function of previous best value.
Passed STC:
https://tests.stockfishchess.org/tests/view/6691a52ec6827afcdcee1569
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 55456 W: 14449 L: 14107 D: 26900
Ptnml(0-2): 174, 6416, 14193, 6784, 161
Passed LTC:
https://tests.stockfishchess.org/tests/view/6691aac1c6827afcdcee1625
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 107940 W: 27530 L: 27065 D: 53345
Ptnml(0-2): 52, 11787, 29840, 12226, 65
closes https://github.com/official-stockfish/Stockfish/pull/5479
bench 1547707
2024-07-15 13:22:31 +02:00
563d268519
Simplify futility_move_count
...
This patch reverts changes from #4032 which was introduced as a speedup.
Modern compilers no longer use DIV/IDIV instructions, potentially making
the explicit branch perform worse. Since evaluations spend significantly
more time now, the impact of the speedup in search diminishes with old
compilers as well.
GCC 14.1.0 profile-build, x86-64-vnni512
```
.text:000000014010FEA9 mov ecx, [rsp+3FB8h+var_3F5C]
...
.text:000000014010FEBD mov r10d, ecx
.text:000000014010FEC0 imul r10d, ecx
.text:000000014010FEC4 mov ecx, dword ptr [rsp+3FB8h+var_3F44+4]
.text:000000014010FEC8 add r10d, 3
.text:000000014010FECC mov r11d, r10d
.text:000000014010FECF sar r11d, 1
.text:000000014010FED2 cmp [rsp+3FB8h+var_3EE7], 0
.text:000000014010FEDA cmovnz r11d, r10d
```
LLVM 18.1.18 profile-build, x86-64-vnni512
```
.text:0000000140001EDC mov [rsp+40h+arg_E0], r13
.text:0000000140001EE4 movsxd rcx, r13d
.text:0000000140001EE7 mov rax, rcx
.text:0000000140001EEA mov [rsp+40h+arg_B8], rcx
.text:0000000140001EF2 imul eax, eax
.text:0000000140001EF5 add eax, 3
.text:0000000140001EF8 mov ecx, [rsp+40h+arg_8C]
.text:0000000140001EFF shrx eax, eax, ecx
.text:0000000140001F04 mov [rsp+40h+arg_190], rax
```
Passed non-regression STC:
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 109504 W: 28420 L: 28280 D: 52804
Ptnml(0-2): 355, 12326, 29273, 12420, 378
https://tests.stockfishchess.org/tests/view/6690dc095034141ae599c5fe
closes https://github.com/official-stockfish/Stockfish/pull/5478
No functional change
2024-07-15 13:19:46 +02:00
Taras Vuk