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
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: Sat Oct 12 16:40:55 2024 +0200
Timestamp: 1728744055

Make low ply history size fixed

Size of low ply history should always be the same, so ensure it.

closes https://github.com/official-stockfish/Stockfish/pull/5630

No functional change
see source
Windows x64 for Haswell CPUs
Windows x64 for modern computers + AVX2
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: Sat Oct 12 16:40:49 2024 +0200
Timestamp: 1728744049

Fix majorPieceKey Updates

Passed STC:
LLR: 2.98 (-2.94,2.94) <0.00,2.00>
Total: 476160 W: 124285 L: 123311 D: 228564 Elo +0.71
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 Elo +0.35
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 Elo +0.40
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
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: Nonlinear2
Date: Sat Oct 12 16:40:37 2024 +0200
Timestamp: 1728744037

Introduce mean squared score for delta adjustments

This patch introduces the value `meanSquaredScore`, which makes the
initial delta sensitive to unstable iterative deepening scores.

Passed STC:
https://tests.stockfishchess.org/tests/view/66fed74286d5ee47d953bb42
LLR: 2.98 (-2.94,2.94) <0.00,2.00>
Total: 71104 W: 18635 L: 18262 D: 34207 Elo +1.82
Ptnml(0-2): 234, 8365, 17993, 8714, 246

Passed LTC:
https://tests.stockfishchess.org/tests/view/6700088e86d5ee47d953bbe9
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 212544 W: 54238 L: 53560 D: 104746 Elo +1.11
Ptnml(0-2): 120, 23093, 59172, 23763, 124

closes https://github.com/official-stockfish/Stockfish/pull/5627

Bench: 1395505
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: Mathias Parnaudeau
Date: Sat Oct 12 16:30:44 2024 +0200
Timestamp: 1728743444

Add autodetection of ppc64 architectures

That allows 'make -j profile-build' work on ppc64 architectures, setting the use of
the appropriate SIMD extension, Altivec or VSX.
For VSX, gcc allows to map SSE2 intrinsics and get benefit of the existing SIMD code.

On PowerMac G5, using altivec provides a performance improvement of 30%.
On Talos 2, using vsx provides a performance improvement of 120%.

closes https://github.com/official-stockfish/Stockfish/pull/5624

No functional change
see source
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: mstembera
Date: Sat Oct 12 16:30:44 2024 +0200
Timestamp: 1728743444

Optimize magics

Reduce the size of the Magics table by half on modern cpu's and lay it
out to match our access pattern. Namely we typically access the magics
for the same square for both bishop and rook back to back so we want
those to be in the same cache line.

https://tests.stockfishchess.org/tests/view/6701c9b386d5ee47d953bcf4
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 121664 W: 31931 L: 31497 D: 58236 Elo +1.24
Ptnml(0-2): 395, 13658, 32322, 14032, 425

A similar patch minus the size reduction finished yellow
https://tests.stockfishchess.org/tests/view/6695f03f4ff211be9d4ec16c
LLR: -2.94 (-2.94,2.94) <0.00,2.00>
Total: 310688 W: 80940 L: 80746 D: 149002 Elo +0.22
Ptnml(0-2): 1119, 35032, 82846, 35230, 1117

closes https://github.com/official-stockfish/Stockfish/pull/5623

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: Sat Oct 12 16:30:44 2024 +0200
Timestamp: 1728743444

Simplify bestvalue formula

Passed STC:
LLR: 2.97 (-2.94,2.94) <-1.75,0.25>
Total: 163680 W: 42689 L: 42605 D: 78386 Elo +0.18
Ptnml(0-2): 619, 19555, 41386, 19683, 597
https://tests.stockfishchess.org/tests/view/66f9451386d5ee47d953b7d9

Passed LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 96498 W: 24582 L: 24438 D: 47478 Elo +0.52
Ptnml(0-2): 62, 10642, 26718, 10744, 83
https://tests.stockfishchess.org/tests/view/66fd765786d5ee47d953ba1c

closes https://github.com/official-stockfish/Stockfish/pull/5622

Bench: 1309815
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: mstembera
Date: Sat Oct 12 16:30:44 2024 +0200
Timestamp: 1728743444

Simplify previous #5608

https://github.com/official-stockfish/Stockfish/pull/5608

STC: https://tests.stockfishchess.org/tests/view/66fb1bab86d5ee47d953b8cc
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 25536 W: 6797 L: 6560 D: 12179 Elo +3.22
Ptnml(0-2): 93, 2953, 6460, 3148, 114

LTC https://tests.stockfishchess.org/tests/view/66fb690e86d5ee47d953b8eb
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 225114 W: 57200 L: 57188 D: 110726 Elo +0.02
Ptnml(0-2): 197, 25076, 61995, 25096, 193

closes https://github.com/official-stockfish/Stockfish/pull/5621

Bench: 1570076
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: Sat Oct 12 16:30:44 2024 +0200
Timestamp: 1728743444

Temporarily fix clang-format mismatch

closes https://github.com/official-stockfish/Stockfish/pull/5620

No functional change
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: Linmiao Xu
Date: Sat Oct 12 16:30:44 2024 +0200
Timestamp: 1728743444

Simplify evaluation scaling

Set digits in adjusted eval params all to 7.

Passed non-regression STC:
https://tests.stockfishchess.org/tests/view/66fc493d86d5ee47d953b94c
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 57696 W: 15098 L: 14898 D: 27700 Elo +1.20
Ptnml(0-2): 205, 6784, 14678, 6968, 213

Passed non-regression LTC:
https://tests.stockfishchess.org/tests/view/66fd4b9386d5ee47d953b9d5
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 93786 W: 23868 L: 23721 D: 46197 Elo +0.54
Ptnml(0-2): 55, 10322, 25993, 10467, 56

closes https://github.com/official-stockfish/Stockfish/pull/5618

Bench: 1277182
see source
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: Ömer Faruk Tutkun
Date: Sat Oct 12 16:30:44 2024 +0200
Timestamp: 1728743444

Introduce Continuation Correction History

Continuation correction history uses last 2 move to correct static eval.

ContCorrHist first introduced by @martinnovaak in
Motor(https://github.com/martinnovaak/motor/pull/162). Earlier ideas
using last move to correct eval is introduced by @MinusKelvin in
Ice4(https://github.com/MinusKelvin/ice4/commit/45daf7d9ea64ea4efaf0d2b4e99f53e12e08c838)

Passed STC:

LLR: 2.96 (-2.94,2.94) <0.00,2.00>
Total: 310144 W: 81267 L: 80538 D: 148339 Elo +0.82
Ptnml(0-2): 1160, 36607, 78834, 37286, 1185
https://tests.stockfishchess.org/tests/view/66f96cbc86d5ee47d953b7f7

Passed LTC:

LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 97470 W: 24892 L: 24447 D: 48131 Elo +1.59
Ptnml(0-2): 63, 10631, 26915, 11050, 76
https://tests.stockfishchess.org/tests/view/66fd59bc86d5ee47d953b9ea

closes https://github.com/official-stockfish/Stockfish/pull/5617

Bench: 1143382
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: Taras Vuk
Date: Fri Oct 4 08:35:08 2024 +0200
Timestamp: 1728023708

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 Elo +2.00
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 Elo +1.38
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
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: Fri Oct 4 08:32:21 2024 +0200
Timestamp: 1728023541

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 Elo +1.02
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 Elo +2.71
Ptnml(0-2): 33, 4518, 11795, 4855, 30

closes https://github.com/official-stockfish/Stockfish/pull/5614

Bench 1264335
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: Linmiao Xu
Date: Fri Oct 4 08:29:09 2024 +0200
Timestamp: 1728023349

Remove evaluation grain

Passed non-regression STC:
https://tests.stockfishchess.org/tests/view/66fa345a86d5ee47d953b86e
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 39776 W: 10528 L: 10306 D: 18942 Elo +1.94
Ptnml(0-2): 134, 4674, 10063, 4870, 147

Passed non-regression LTC:
https://tests.stockfishchess.org/tests/view/66facfb886d5ee47d953b8a8
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 64230 W: 16484 L: 16305 D: 31441 Elo +0.97
Ptnml(0-2): 38, 7195, 17483, 7348, 51

closes https://github.com/official-stockfish/Stockfish/pull/5613

bench 1013135
see source
Windows x64 for modern computers + AVX2
Linux x64 for Haswell CPUs
Linux x64 for modern computers + AVX2
Linux x64 for modern computers
Linux x64 + SSSE3
Linux x64
Author: Linmiao Xu
Date: Tue Oct 1 21:02:44 2024 +0200
Timestamp: 1727809364

Tweak 7 eval params

Values found from 120k / 120k spsa games at 30+0.3

Passed STC:
https://tests.stockfishchess.org/tests/view/66ecd7ce86d5ee47d953b003
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 241312 W: 62994 L: 62373 D: 115945 Elo +0.89
Ptnml(0-2): 754, 28684, 61280, 29063, 875

Passed LTC:
https://tests.stockfishchess.org/tests/view/66f1f3a286d5ee47d953b331
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 304896 W: 77580 L: 76709 D: 150607 Elo +0.99
Ptnml(0-2): 198, 33413, 84360, 34274, 203

closes https://github.com/official-stockfish/Stockfish/pull/5611

bench 1173651
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: Taras Vuk
Date: Tue Oct 1 20:59:17 2024 +0200
Timestamp: 1727809157

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 Elo +0.77
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 Elo +1.14
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
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: Sat Sep 28 18:01:31 2024 +0200
Timestamp: 1727539291

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 Elo +0.05
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 Elo +0.49
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 Elo +0.05
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
see source
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: peregrineshahin
Date: Sat Sep 28 18:01:31 2024 +0200
Timestamp: 1727539291

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 Elo +3.21
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 Elo +2.05
Ptnml(0-2): 24, 6725, 17555, 7057, 43

closes https://github.com/official-stockfish/Stockfish/pull/5608

bench: 1452807
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: Tomasz Sobczyk
Date: Sat Sep 28 18:01:26 2024 +0200
Timestamp: 1727539286

Add a standardized benchmark command `speedtest`.

`speedtest [threads] [hash_MiB] [time_s]`. `threads` default to system concurrency. `hash_MiB` defaults to `threads*128`. `time_s` defaults to 150.

Intended to be used with default parameters, as a stable hardware benchmark.

Example:
```
C:\dev\stockfish-master\src>stockfish.exe speedtest
Stockfish dev-20240928-nogit by the Stockfish developers (see AUTHORS file)
info string Using 16 threads
Warmup position 3/3
Position 258/258
===========================
Version : Stockfish dev-20240928-nogit
Compiled by : g++ (GNUC) 13.2.0 on MinGW64
Compilation architecture : x86-64-vnni256
Compilation settings : 64bit VNNI BMI2 AVX2 SSE41 SSSE3 SSE2 POPCNT
Compiler __VERSION__ macro : 13.2.0
Large pages : yes
User invocation : speedtest
Filled invocation : speedtest 16 2048 150
Available processors : 0-15
Thread count : 16
Thread binding : none
TT size [MiB] : 2048
Hash max, avg [per mille] :
single search : 40, 21
single game : 631, 428
Total nodes searched : 2099917842
Total search time [s] : 153.937
Nodes/second : 13641410
```

-------------------------------

Small unrelated tweaks:
- Network verification output is now handled as a callback.
- TT hashfull queries allow specifying maximum entry age.

closes https://github.com/official-stockfish/Stockfish/pull/5354

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: Nonlinear2
Date: Sat Sep 28 17:22:33 2024 +0200
Timestamp: 1727536953

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 Elo +2.24
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 Elo +0.86
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
see source
Windows x64 for Haswell CPUs
Windows x64 for modern computers + AVX2
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: Joost VandeVondele
Date: Sat Sep 28 17:17:44 2024 +0200
Timestamp: 1727536664

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 Elo +3.03
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 Elo +1.06
Ptnml(0-2): 173, 26211, 67202, 26979, 158

closes https://github.com/official-stockfish/Stockfish/pull/5606

Bench: 1677953
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 Sep 28 17:17:14 2024 +0200
Timestamp: 1727536634

Removed ROOK threatenedByPawn

Passed STC:
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 56608 W: 14788 L: 14588 D: 27232 Elo +1.23
Ptnml(0-2): 162, 6763, 14313, 6845, 221
https://tests.stockfishchess.org/tests/view/66e83f9c86d5ee47d953ab1d

Passed LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 175758 W: 44501 L: 44438 D: 86819 Elo +0.12
Ptnml(0-2): 125, 19489, 48601, 19526, 138
https://tests.stockfishchess.org/tests/view/66e882d486d5ee47d953ab8a

closes https://github.com/official-stockfish/Stockfish/pull/5601

bench: 1241271
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: Wencey Wang
Date: Sat Sep 28 17:12:12 2024 +0200
Timestamp: 1727536332

Fix native arch builds on loongarch64

Adds support for LSX and LASX

closes https://github.com/official-stockfish/Stockfish/pull/5600

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: Shawn Xu
Date: Tue Sep 17 21:01:43 2024 +0200
Timestamp: 1726599703

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 Elo +4.41
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 Elo +8.70
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
see source
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: Michael Chaly
Date: Tue Sep 17 20:54:02 2024 +0200
Timestamp: 1726599242

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 Elo +1.23
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 Elo +0.94
Ptnml(0-2): 277, 42165, 105089, 43162, 296

closes https://github.com/official-stockfish/Stockfish/pull/5595

Bench: 1611283
see source
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: Shawn Xu
Date: Tue Sep 17 20:50:30 2024 +0200
Timestamp: 1726599030

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 Elo -0.08
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 Elo +0.33
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
see source

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