Stockfish Development Versions are build automatically if there are changes on the master branch in the git repository (https://github.com/official-stockfish/Stockfish). Use it at your own risk.
They are compiled with gcc 11.2/mingw 10 on Ubuntu 22.04.

!! latest version !!


Windows x64 for Haswell CPUs
Windows x64 for modern computers + AVX2
Windows x64 for modern computers
Windows x64 + SSSE3
Windows x64
Linux x64 for Haswell CPUs
Linux x64 for modern computers + AVX2
Linux x64 for modern computers
Linux x64 + SSSE3
Linux x64
Author: Shawn Xu
Date: Sun Aug 24 20:10:43 2025 +0200
Timestamp: 1756059043

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 Elo +0.00
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 Elo +0.78
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
see source
Windows x64 for Haswell CPUs
Windows x64 for modern computers + AVX2
Windows x64 for modern computers
Windows x64 + SSSE3
Windows x64
Linux x64 for Haswell CPUs
Linux x64 for modern computers + AVX2
Linux x64 for modern computers
Linux x64 + SSSE3
Linux x64
Author: Stefan Geschwentner
Date: Sun Aug 24 20:07:50 2025 +0200
Timestamp: 1756058870

Less reduction for later threads.

Give "(thread id mod 8) * 64" less reductions (up to nearly a half ply).

Passed SMP STC:
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 413176 W: 106496 L: 105666 D: 201014 Elo +0.70
Ptnml(0-2): 504, 46732, 111266, 47602, 484
https://tests.stockfishchess.org/tests/view/68a24aeeb6fb3300203bbdc4

Passed SMP LTC:
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 60420 W: 15622 L: 15268 D: 29530 Elo +2.04
Ptnml(0-2): 11, 6106, 17632, 6440, 21
https://tests.stockfishchess.org/tests/view/68a2c2ffb6fb3300203bc516

closes https://github.com/official-stockfish/Stockfish/pull/6249

No functional change
see source
Windows x64 for Haswell CPUs
Windows x64 for modern computers + AVX2
Windows x64 for modern computers
Windows x64 + SSSE3
Windows x64
Linux x64 for Haswell CPUs
Linux x64 for modern computers + AVX2
Linux x64 for modern computers
Linux x64 + SSSE3
Linux x64
Author: FauziAkram
Date: Sun Aug 24 20:01:01 2025 +0200
Timestamp: 1756058461

Remove cap from a bonusScale formula

Passed STC:
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 127264 W: 33159 L: 33042 D: 61063 Elo +0.32
Ptnml(0-2): 336, 14509, 33866, 14544, 377
https://tests.stockfishchess.org/tests/view/68a63fccb6fb3300203bc818

Passed LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 469512 W: 120094 L: 120331 D: 229087 Elo -0.18
Ptnml(0-2): 238, 51317, 131885, 51076, 240
https://tests.stockfishchess.org/tests/view/68a8d867b6fb3300203bcab5

closes https://github.com/official-stockfish/Stockfish/pull/6260

Bench: 2433974
see source
Windows x64 for Haswell CPUs
Windows x64 for modern computers + AVX2
Windows x64 + SSSE3
Windows x64
Linux x64 for Haswell CPUs
Linux x64 for modern computers + AVX2
Linux x64 for modern computers
Linux x64 + SSSE3
Linux x64
Author: Michael Chaly
Date: Sun Aug 24 19:58:49 2025 +0200
Timestamp: 1756058329

Small simplification in probCut movepicker

Remove no longer required condition for tt moves. The idea is that if tt the value is
greater than probCut beta try tt move that is a capture anyway - even if it
doesn't pass SEE check. This idea in various implementations passed some STCs
and was looking decent at LTCs as a gainer.

Passed STC:
https://tests.stockfishchess.org/tests/view/68aa1ee075da51a345a5a805
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 136160 W: 35189 L: 35079 D: 65892 Elo +0.28
Ptnml(0-2): 436, 16083, 34891, 16275, 395

Passed LTC:
https://tests.stockfishchess.org/tests/view/68aa91d375da51a345a5a884
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 80022 W: 20652 L: 20492 D: 38878 Elo +0.69
Ptnml(0-2): 33, 8717, 22357, 8865, 39

closes https://github.com/official-stockfish/Stockfish/pull/6259

Bench: 2307940
see source
Windows x64 for Haswell CPUs
Windows x64 for modern computers
Windows x64
Linux x64 for Haswell CPUs
Linux x64 for modern computers + AVX2
Linux x64 for modern computers
Linux x64 + SSSE3
Linux x64
Author: Shawn Xu
Date: Sun Aug 24 19:55:35 2025 +0200
Timestamp: 1756058135

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 Elo +5.23
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 Elo +0.53
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
see source
Windows x64 for Haswell CPUs
Windows x64 for modern computers + AVX2
Windows x64 for modern computers
Windows x64
Linux x64 for Haswell CPUs
Linux x64 for modern computers + AVX2
Linux x64 for modern computers
Linux x64 + SSSE3
Linux x64
Author: Shawn Xu
Date: Sun Aug 24 19:52:42 2025 +0200
Timestamp: 1756057962

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 Elo +1.58
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 Elo +0.24
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
see source
Windows x64 for Haswell CPUs
Windows x64 for modern computers + AVX2
Windows x64 for modern computers
Windows x64 + SSSE3
Windows x64
Linux x64 for Haswell CPUs
Linux x64 for modern computers + AVX2
Linux x64 for modern computers
Linux x64 + SSSE3
Linux x64
Author: Shawn Xu
Date: Sun Aug 24 19:50:51 2025 +0200
Timestamp: 1756057851

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 Elo +0.46
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 Elo +0.53
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 Elo +2.22
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
see source
Windows x64 for Haswell CPUs
Windows x64 for modern computers
Windows x64 + SSSE3
Windows x64
Linux x64 for Haswell CPUs
Linux x64 for modern computers + AVX2
Linux x64 for modern computers
Linux x64 + SSSE3
Linux x64
Author: Daniel Monroe
Date: Sun Aug 24 19:47:20 2025 +0200
Timestamp: 1756057640

Remove upper bound in see margin

Passed simplification STC
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 99840 W: 25965 L: 25815 D: 48060 Elo +0.52
Ptnml(0-2): 326, 11708, 25688, 11886, 312
https://tests.stockfishchess.org/tests/view/68a24504b6fb3300203bbdae

Passed simplification LTC
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 248388 W: 63544 L: 63556 D: 121288 Elo -0.02
Ptnml(0-2): 125, 27132, 69709, 27086, 142
https://tests.stockfishchess.org/tests/view/68a24f3bb6fb3300203bbdee

closes https://github.com/official-stockfish/Stockfish/pull/6250

Bench: 2432765
see source
Windows x64 for Haswell CPUs
Windows x64 for modern computers + AVX2
Windows x64 for modern computers
Windows x64 + SSSE3
Windows x64
Linux x64 for Haswell CPUs
Linux x64 for modern computers + AVX2
Linux x64 for modern computers
Linux x64 + SSSE3
Linux x64
Author: Daniel Samek
Date: Sun Aug 24 19:45:23 2025 +0200
Timestamp: 1756057523

Remove depth reduction in the full-depth search

Passed simplification STC:
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 217184 W: 56218 L: 56195 D: 104771 Elo +0.04
Ptnml(0-2): 627, 25673, 55985, 25664, 643
https://tests.stockfishchess.org/tests/view/68a21e0eb6fb3300203bbcf3

Passed simplification LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 30474 W: 7923 L: 7713 D: 14838 Elo +2.39
Ptnml(0-2): 20, 3205, 8569, 3431, 12
https://tests.stockfishchess.org/tests/view/68a2adacb6fb3300203bc3f9

closes https://github.com/official-stockfish/Stockfish/pull/6246

bench 2626263
see source
Windows x64 for Haswell CPUs
Windows x64 for modern computers + AVX2
Windows x64 for modern computers
Windows x64 + SSSE3
Linux x64 for Haswell CPUs
Linux x64 for modern computers + AVX2
Linux x64 for modern computers
Linux x64 + SSSE3
Linux x64
Author: Daniel Monroe
Date: Sun Aug 24 19:43:48 2025 +0200
Timestamp: 1756057428

Simplify depth condition in prior reduction

Passed simplification STC
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 172864 W: 45085 L: 45015 D: 82764 Elo +0.14
Ptnml(0-2): 516, 20456, 44405, 20552, 503
https://tests.stockfishchess.org/tests/view/68a24791b6fb3300203bbdb6

Passed simplification LTC
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 84738 W: 21733 L: 21578 D: 41427 Elo +0.64
Ptnml(0-2): 49, 9169, 23780, 9320, 51
https://tests.stockfishchess.org/tests/view/68a2665ab6fb3300203bc269

closes https://github.com/official-stockfish/Stockfish/pull/6244

Bench: 2131292
see source
Windows x64 for Haswell CPUs
Windows x64 for modern computers + AVX2
Windows x64 for modern computers
Windows x64 + SSSE3
Windows x64
Linux x64 for Haswell CPUs
Linux x64 for modern computers + AVX2
Linux x64 for modern computers
Linux x64 + SSSE3
Linux x64
Author: Disservin
Date: Sun Aug 24 19:40:40 2025 +0200
Timestamp: 1756057240

CI: fix typo in flag

closes https://github.com/official-stockfish/Stockfish/pull/6247

No functional change
see source
Windows x64 for Haswell CPUs
Windows x64 for modern computers + AVX2
Windows x64 for modern computers
Windows x64 + SSSE3
Windows x64
Linux x64 for Haswell CPUs
Linux x64 for modern computers + AVX2
Linux x64 for modern computers
Linux x64 + SSSE3
Linux x64
Author: FauziAkram
Date: Sun Aug 24 19:39:49 2025 +0200
Timestamp: 1756057189

Set back static constexpr

closes https://github.com/official-stockfish/Stockfish/pull/6243

No functional change
see source
Windows x64 for Haswell CPUs
Windows x64 for modern computers + AVX2
Windows x64 + SSSE3
Windows x64
Linux x64 for Haswell CPUs
Linux x64 for modern computers + AVX2
Linux x64 for modern computers
Linux x64 + SSSE3
Linux x64
Author: Myself
Date: Sun Aug 24 19:37:58 2025 +0200
Timestamp: 1756057078

Speedup_threat_by_lesser

This patch could have been considered a non-functional speedup, but changing
the ranking of illegal moves.

Passed STC:
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 131040 W: 34247 L: 33792 D: 63001 Elo +1.21
Ptnml(0-2): 407, 15281, 33675, 15764, 393
https://tests.stockfishchess.org/tests/live_elo/68a9a75b75da51a345a5a66d

Passed LTC:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 280146 W: 72055 L: 71242 D: 136849 Elo +1.01
Ptnml(0-2): 153, 30252, 78438, 31089, 141
https://tests.stockfishchess.org/tests/view/68a9f58475da51a345a5a6e0

closes https://github.com/official-stockfish/Stockfish/pull/6261

Bench: 2321931
see source
Windows x64 for Haswell CPUs
Windows x64 for modern computers + AVX2
Windows x64 + SSSE3
Windows x64
Linux x64 for Haswell CPUs
Linux x64 for modern computers + AVX2
Linux x64 for modern computers
Linux x64 + SSSE3
Linux x64
Author: Stefan Geschwentner
Date: Sun Aug 24 19:30:31 2025 +0200
Timestamp: 1756056631

Remove log depth reduction terms.

Motivated by the elo loss of last VVLTC regression test i remove the new log
depth reductions (tuned at STC) to regain strength at VVLTC. The constant terms
are adjusted based on the old values and the changes from the last added VVLTC
tuning.

Passed VVLTC with STC bound:
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 53802 W: 14030 L: 13740 D: 26032 Elo +1.87
Ptnml(0-2): 5, 4924, 16754, 5212, 6
https://tests.stockfishchess.org/tests/view/68a9a9f575da51a345a5a675

Passed VVLTC with LTC bound:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 53658 W: 14022 L: 13699 D: 25937 Elo +2.09
Ptnml(0-2): 3, 4894, 16712, 5217, 3
https://tests.stockfishchess.org/tests/view/68a8d2b2b6fb3300203bca77

closes https://github.com/official-stockfish/Stockfish/pull/6257

Bench: 2566780
see source
Windows x64 for Haswell CPUs
Windows x64 for modern computers
Windows x64 + SSSE3
Windows x64
Linux x64 for Haswell CPUs
Linux x64 for modern computers + AVX2
Linux x64 for modern computers
Linux x64 + SSSE3
Linux x64
Author: FauziAkram
Date: Sun Aug 17 22:46:04 2025 +0200
Timestamp: 1755463564

VVLTC tweak

Passed VVLTC with STC bounds:
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 60796 W: 15908 L: 15609 D: 29279 Elo +1.71
Ptnml(0-2): 6, 5598, 18889, 5901, 4
https://tests.stockfishchess.org/tests/view/68a1fbfeb6fb3300203bbc5c

Passed VVLTC with LTC bounds:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 24914 W: 6528 L: 6256 D: 12130 Elo +3.79
Ptnml(0-2): 4, 2263, 7648, 2541, 1
https://tests.stockfishchess.org/tests/view/68a211aeb6fb3300203bbca7

closes https://github.com/official-stockfish/Stockfish/pull/6241

Bench: 2130122
see source
Windows x64 for Haswell CPUs
Windows x64 for modern computers
Windows x64 + SSSE3
Windows x64
Linux x64 for Haswell CPUs
Linux x64 for modern computers + AVX2
Linux x64 for modern computers
Linux x64 + SSSE3
Linux x64
Author: Stefan Geschwentner
Date: Sun Aug 17 22:39:49 2025 +0200
Timestamp: 1755463189

Bigger thread dependent initial window.

Increase the initial delta of the aspiration window by "thread id mod 8".

Passed SMP STC:
LLR: 2.96 (-2.94,2.94) <0.00,2.00>
Total: 106176 W: 27470 L: 27069 D: 51637 Elo +1.31
Ptnml(0-2): 121, 12032, 28386, 12423, 126
https://tests.stockfishchess.org/tests/view/68a178fab6fb3300203bbaec

Passed SMP LTC:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 133076 W: 34272 L: 33772 D: 65032 Elo +1.31
Ptnml(0-2): 38, 13709, 38537, 14223, 31
https://tests.stockfishchess.org/tests/view/68a1b5d2b6fb3300203bbb71

closes https://github.com/official-stockfish/Stockfish/pull/6239

No functional change
see source
Windows x64 for Haswell CPUs
Windows x64 for modern computers + AVX2
Windows x64 for modern computers
Windows x64 + SSSE3
Windows x64
Linux x64 for Haswell CPUs
Linux x64 for modern computers + AVX2
Linux x64 for modern computers
Linux x64 + SSSE3
Linux x64
Author: 87
Date: Sun Aug 17 22:38:09 2025 +0200
Timestamp: 1755463089

Add performance warning comment for vpcompressw

closes https://github.com/official-stockfish/Stockfish/pull/6237

No functional change
see source
Windows x64 for Haswell CPUs
Windows x64 for modern computers + AVX2
Windows x64 for modern computers
Windows x64 + SSSE3
Windows x64
Linux x64 for Haswell CPUs
Linux x64 for modern computers + AVX2
Linux x64 for modern computers
Linux x64 + SSSE3
Linux x64
Author: Stefan Geschwentner
Date: Sun Aug 17 22:35:03 2025 +0200
Timestamp: 1755462903

Fix undefined behavior in stalemate trap detection.

An important part of it is a function which detects if we can move a king or
pawn. If this function called before quiet move generation phase the end of the
checked move list is undefined (Thanks to AliceRoselia pointing out we have
some problem because of wrong bench in a test).

This problem exists also in master but is really rarely triggered (thanks to
vondele which found one) but it seen significant more often if the capture
order score is increased.

This fix now simply assumes in this case (and other similiar cases) that a king
or pawn can move without checking any moves.

Passed non-regression STC (with default book):
LLR: 3.03 (-2.94,2.94) <-1.75,0.25>
Total: 203008 W: 52465 L: 52424 D: 98119 Elo +0.07
Ptnml(0-2): 498, 20293, 59893, 20310, 510
https://tests.stockfishchess.org/tests/view/68a06ec5fd8719b088c8dc1a

Passed non-regression STC (with stalemates book):
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 31616 W: 14418 L: 14366 D: 2832 Elo +0.57
Ptnml(0-2): 1, 189, 15375, 243, 0
https://tests.stockfishchess.org/tests/view/68a07538fd8719b088c8dc1f

closes https://github.com/official-stockfish/Stockfish/pull/6235

Bench: 2996176
see source
Windows x64 for Haswell CPUs
Windows x64 for modern computers + AVX2
Windows x64 for modern computers
Windows x64 + SSSE3
Windows x64
Linux x64 for Haswell CPUs
Linux x64 for modern computers + AVX2
Linux x64 for modern computers
Linux x64 + SSSE3
Linux x64
Author: Joost VandeVondele
Date: Sun Aug 17 22:32:03 2025 +0200
Timestamp: 1755462723

Update sde action to 2.4, switch to 9.33.0

older version no longer downloadable.

closes https://github.com/official-stockfish/Stockfish/pull/6240

No functional change
see source
Windows x64 for Haswell CPUs
Windows x64 for modern computers + AVX2
Windows x64 for modern computers
Windows x64 + SSSE3
Windows x64
Linux x64 for Haswell CPUs
Linux x64 for modern computers + AVX2
Linux x64 for modern computers
Linux x64 + SSSE3
Linux x64
Author: Daniel Monroe
Date: Sat Aug 16 12:12:07 2025 +0200
Timestamp: 1755339127

Simplify dual bonuses

Merge dual capture/quiet bonuses into one

Passed simplification STC
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 223200 W: 57868 L: 57854 D: 107478 Elo +0.02
Ptnml(0-2): 689, 26441, 57296, 26515, 659
https://tests.stockfishchess.org/tests/view/6898d28e0049e8ccef9d6384

Passed simplification LTC
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 147270 W: 37750 L: 37659 D: 71861 Elo +0.21
Ptnml(0-2): 84, 15869, 41633, 15970, 79
https://tests.stockfishchess.org/tests/view/68990fe30049e8ccef9d643c

closes https://github.com/official-stockfish/Stockfish/pull/6226

Bench: 2996176
see source
Windows x64 for Haswell CPUs
Windows x64 for modern computers + AVX2
Windows x64 for modern computers
Windows x64 + SSSE3
Linux x64 for Haswell CPUs
Linux x64 for modern computers + AVX2
Linux x64 for modern computers
Linux x64 + SSSE3
Linux x64
Author: Daniel Monroe
Date: Sat Aug 16 12:06:00 2025 +0200
Timestamp: 1755338760

Simplify depth term in reductions

Passed simplification STC
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 317344 W: 82352 L: 82442 D: 152550 Elo -0.10
Ptnml(0-2): 999, 37395, 81907, 37439, 932
https://tests.stockfishchess.org/tests/live_elo/68976798f8a258623dda6c46

Passed simplification LTC
LLR: 2.97 (-2.94,2.94) <-1.75,0.25>
Total: 291708 W: 74733 L: 74787 D: 142188 Elo -0.06
Ptnml(0-2): 159, 31813, 81956, 31775, 151
https://tests.stockfishchess.org/tests/live_elo/689791a5f8a258623dda6d03

closes https://github.com/official-stockfish/Stockfish/pull/6225

Bench: 2436991
see source
Windows x64 for Haswell CPUs
Windows x64 for modern computers + AVX2
Windows x64 for modern computers
Windows x64 + SSSE3
Windows x64
Linux x64 for Haswell CPUs
Linux x64 for modern computers + AVX2
Linux x64 for modern computers
Linux x64 + SSSE3
Linux x64
Author: Kevin Lu
Date: Sat Aug 16 12:01:19 2025 +0200
Timestamp: 1755338479

Remove completedDepth condition for SE

Just removing the term

Passed STC:
LLR: 3.27 (-2.94,2.94) <-1.75,0.25>
Total: 179840 W: 47211 L: 47126 D: 85503 Elo +0.16
Ptnml(0-2): 567, 17929, 52879, 17942, 603
https://tests.stockfishchess.org/tests/view/688bdd88502b34dd5e7111ea

Passed LTC:
LLR: 3.26 (-2.94,2.94) <-1.75,0.25>
Total: 150708 W: 38738 L: 38637 D: 73333 Elo +0.23
Ptnml(0-2): 79, 12922, 49262, 13001, 90
https://tests.stockfishchess.org/tests/view/688ce857f17748b4d23c8026

Passed VLTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 288312 W: 74104 L: 74152 D: 140056 Elo -0.06
Ptnml(0-2): 44, 26732, 90657, 26674, 49
https://tests.stockfishchess.org/tests/view/688ec4f57d68fe4f7f130ee3

closes https://github.com/official-stockfish/Stockfish/pull/6221

functional at higher depths

Bench: 3002300
see source
Windows x64 for Haswell CPUs
Windows x64 for modern computers + AVX2
Windows x64 for modern computers
Windows x64 + SSSE3
Windows x64
Linux x64 for Haswell CPUs
Linux x64 for modern computers + AVX2
Linux x64 for modern computers
Linux x64 + SSSE3
Linux x64
Author: FauziAkram
Date: Sat Aug 16 11:57:44 2025 +0200
Timestamp: 1755338264

Simplify beta formula

Passed STC:
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 152384 W: 39907 L: 39814 D: 72663 Elo +0.21
Ptnml(0-2): 557, 17958, 39053, 18083, 541
https://tests.stockfishchess.org/tests/view/6890b66692fcad741b804a10

Passed LTC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 98688 W: 25411 L: 25270 D: 48007 Elo +0.50
Ptnml(0-2): 45, 10692, 27743, 10805, 59
https://tests.stockfishchess.org/tests/view/6896019c618946ab878347b0

closes: https://github.com/official-stockfish/Stockfish/pull/6220

bench: 3002300
see source
Windows x64 for Haswell CPUs
Windows x64 for modern computers + AVX2
Windows x64 for modern computers
Windows x64 + SSSE3
Windows x64
Linux x64 for Haswell CPUs
Linux x64 for modern computers + AVX2
Linux x64 for modern computers
Linux x64 + SSSE3
Linux x64
Author: Stefan Geschwentner
Date: Sat Aug 16 11:51:39 2025 +0200
Timestamp: 1755337899

Add log depth as term to reduction factors.

Replace most reduction factors with a linear term of the form X + Y * msb(depth) (using msb(depth) as simple and fast approximation for log(depth))
and tune the weights with following SPSA test: https://tests.stockfishchess.org/tests/view/689903860049e8ccef9d6415.

Here the tuned values of X[8] and Y[8] were ignored because a simple test with this parameters alone failed badly (https://tests.stockfishchess.org/tests/view/68992b350049e8ccef9d6482).

Passed STC:
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 32448 W: 8651 L: 8342 D: 15455 Elo +3.31
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 Elo +1.85
Ptnml(0-2): 37, 7908, 20659, 8271, 52
https://tests.stockfishchess.org/tests/view/689abbe7fd8719b088c8d514

closes https://github.com/official-stockfish/Stockfish/pull/6229

Bench: 3151102
see source
Windows x64 for Haswell CPUs
Windows x64 for modern computers + AVX2
Windows x64 for modern computers
Windows x64 + SSSE3
Windows x64
Linux x64 for Haswell CPUs
Linux x64 for modern computers + AVX2
Linux x64 for modern computers
Linux x64 + SSSE3
Linux x64
Author: mstembera
Date: Sat Aug 16 11:46:39 2025 +0200
Timestamp: 1755337599

Avoid using _mm512_storeu_epi16()

gcc 9 & 10 do not provide this function, instead use the generic _mm512_storeu_si512

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95483

https://tests.stockfishchess.org/actions?max_actions=1&action=&user=&text=&before=1755266300.455175&run_id=

closes https://github.com/official-stockfish/Stockfish/pull/6231

No functional change
see source

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