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 21.10.
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!! 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: J. Oster
Date: Sat Jan 22 10:48:24 2022 +0100
Timestamp: 1642844904

Simplify limiting extensions.

Replace the current method for limiting extensions to avoid search getting stuck
with a much simpler method.

the test position in https://github.com/official-stockfish/Stockfish/commit/73018a03375b4b72ee482eb5a4a2152d7e4f0aac
can still be searched without stuck search.

fixes #3815 where the search now makes progress with rootDepth

shows robust behavior in a d10 search for 1M positions.

passed STC
https://tests.stockfishchess.org/tests/view/61e303e3babab931824dfb18
LLR: 2.94 (-2.94,2.94) <-2.25,0.25>
Total: 57568 W: 15449 L: 15327 D: 26792 Elo +0.74
Ptnml(0-2): 243, 6211, 15779, 6283, 268

passed LTC
https://tests.stockfishchess.org/tests/view/61e3586cbabab931824e091c
LLR: 2.96 (-2.94,2.94) <-2.25,0.25>
Total: 128200 W: 34632 L: 34613 D: 58955 Elo +0.05
Ptnml(0-2): 124, 12559, 38710, 12588, 119

closes https://github.com/official-stockfish/Stockfish/pull/3899

Bench: 4550528
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: Thu Jan 20 18:34:16 2022 +0100
Timestamp: 1642700056

Revert -flto=auto on mingw

causes issues on some installations (glinscott/fishtest#1255).

closes https://github.com/official-stockfish/Stockfish/pull/3898

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: ppigazzini
Date: Wed Jan 19 22:26:20 2022 +0100
Timestamp: 1642627580

Improve Makefile for Windows native builds

A Windows Native Build (WNB) can be done:
- on Windows, using a recent mingw-w64 g++/clang compiler
distributed by msys2, cygwin and others
- on Linux, using mingw-w64 g++ to cross compile

Improvements:
- check for a WNB in a proper way and set a variable to simplify the code
- set the proper EXE for a WNB
- use the proper name for the mingw-w64 clang compiler
- use the static linking for a WNB
- use wine to make a PGO cross compile on Linux (also with Intel SDE)
- enable the LTO build for mingw-w64 g++ compiler
- set `lto=auto` to use the make's job server, if available, or otherwise
to fall back to autodetection of the number of CPU threads
- clean up all the temporary LTO files saved in the local directory

Tested on:
- msys2 MINGW64 (g++), UCRT64 (g++), MINGW32 (g++), CLANG64 (clang)
environments
- cygwin mingw-w64 g++
- Ubuntu 18.04 & 21.10 mingw-w64 PGO cross compile (also with Intel SDE)

closes #3891

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: ppigazzini
Date: Wed Jan 19 19:21:10 2022 +0100
Timestamp: 1642616470

Add msys2 Clang x86_64 to GitHub Action matrix

Also use Windows Server 2022 virtual environment for msys2 builds.

closes https://github.com/official-stockfish/Stockfish/pull/3893

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: Rui Coelho
Date: Mon Jan 17 19:48:23 2022 +0100
Timestamp: 1642445303

Use average complexity for time management

This patch is a variant of the idea by locutus2 (https://tests.stockfishchess.org/tests/view/61e1f24cb1f9959fe5d88168) to adjust the total time depending on the average complexity of the position.

Passed STC
LLR: 2.94 (-2.94,2.94) <0.00,2.50>
Total: 39664 W: 10765 L: 10487 D: 18412 Elo +2.44
Ptnml(0-2): 162, 4213, 10837, 4425, 195
https://tests.stockfishchess.org/tests/view/61e2df8b65a644da8c9ea708

Passed LTC
LLR: 2.94 (-2.94,2.94) <0.50,3.00>
Total: 127656 W: 34505 L: 34028 D: 59123 Elo +1.30
Ptnml(0-2): 116, 12435, 38261, 12888, 128
https://tests.stockfishchess.org/tests/view/61e31db5babab931824dff5e

closes https://github.com/official-stockfish/Stockfish/pull/3892

Bench: 4464962
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: proukornew
Date: Mon Jan 17 19:47:32 2022 +0100
Timestamp: 1642445252

Improve logic on mingw

There is no need to point g++, if we explicitly choose mingw.

Now for cygwin:

make COMP=mingw ARCH=x86-64-modern build

closes https://github.com/official-stockfish/Stockfish/pull/3860

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: Rui Coelho
Date: Thu Jan 13 22:25:01 2022 +0100
Timestamp: 1642109101

Use complexity in search

This patch uses the complexity measure (from #3875) as a heuristic for null move pruning.
Hopefully, there may be room to use it in other pruning techniques.
I would like to thank vondele and locutus2 for the feedback and suggestions during testing.

Passed STC
LLR: 2.95 (-2.94,2.94) <0.00,2.50>
Total: 35000 W: 9624 L: 9347 D: 16029 Elo +2.75
Ptnml(0-2): 156, 3894, 9137, 4143, 170
https://tests.stockfishchess.org/tests/view/61dda784c65bf87d6c45ab80

Passed LTC
LLR: 2.94 (-2.94,2.94) <0.50,3.00>
Total: 230776 W: 64227 L: 63454 D: 103095 Elo +1.16
Ptnml(0-2): 1082, 23100, 66380, 23615, 1211
https://tests.stockfishchess.org/tests/view/61ddd0cf3ddbc32543e72c2b

Closes https://github.com/official-stockfish/Stockfish/pull/3890

Bench: 4464962
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: pschneider1968
Date: Thu Jan 13 22:17:27 2022 +0100
Timestamp: 1642108647

Fix Makefile for compilation with clang on Windows

use static compilation and
added exclusion of -latomic for Clang/MSYS2 as per ppigazzini's suggestion

fixes #3872

closes https://github.com/official-stockfish/Stockfish/pull/3873

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: Michael Chaly
Date: Mon Jan 10 19:35:53 2022 +0100
Timestamp: 1641839753

Adjust pruning constants

This patch is a modification of original tuning done by vondele that failed yellow.
Value differences are divided by 2.

Passed STC
https://tests.stockfishchess.org/tests/view/61d918239fea7913d9c64cdf
LLR: 2.94 (-2.94,2.94) <0.00,2.50>
Total: 98968 W: 26248 L: 25858 D: 46862 Elo +1.37
Ptnml(0-2): 392, 11085, 26156, 11443, 408

Passed LTC
https://tests.stockfishchess.org/tests/view/61d99e3c9fea7913d9c663e4
LLR: 2.95 (-2.94,2.94) <0.50,3.00>
Total: 215232 W: 58191 L: 57492 D: 99549 Elo +1.13
Ptnml(0-2): 271, 22124, 62138, 22801, 282

closes https://github.com/official-stockfish/Stockfish/pull/3885

bench 4572746
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 Jan 9 15:49:19 2022 +0100
Timestamp: 1641739759

Tune FRC trapped Bishop patch

now that fishtest can deal with FRC, retune this correction.

Add an additional fen to bench with cornered B and N.

passed STC:
LLR: 2.95 (-2.94,2.94) <0.00,2.50>
Total: 49672 W: 7358 L: 7082 D: 35232 Elo +1.93
Ptnml(0-2): 241, 4329, 15458, 4529, 279
https://tests.stockfishchess.org/tests/view/61d8b7bf9fea7913d9c63cb7

passed LTC:
LLR: 2.95 (-2.94,2.94) <0.50,3.00>
Total: 86688 W: 8308 L: 8007 D: 70373 Elo +1.21
Ptnml(0-2): 92, 4943, 32989, 5212, 108
https://tests.stockfishchess.org/tests/view/61d92dcb9fea7913d9c650ad

closes https://github.com/official-stockfish/Stockfish/pull/3884

Bench: 4326560
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: Sat Jan 8 08:44:49 2022 +0100
Timestamp: 1641627889

Tune a few parameters related to evaluation

based on a SPSA tune (using Autoselect)
https://tests.stockfishchess.org/tests/view/61d5aa63a314fed318a57046

passed STC:
LLR: 2.93 (-2.94,2.94) <0.00,2.50>
Total: 61960 W: 16640 L: 16316 D: 29004 Elo +1.82
Ptnml(0-2): 278, 6934, 16204, 7314, 250
https://tests.stockfishchess.org/tests/view/61d7fe4af5fd40f357469a8d

passed LTC:
LLR: 2.97 (-2.94,2.94) <0.50,3.00>
Total: 79408 W: 21994 L: 21618 D: 35796 Elo +1.65
Ptnml(0-2): 106, 7887, 23331, 8285, 95
https://tests.stockfishchess.org/tests/view/61d836b7f5fd40f35746a3d5

closes https://github.com/official-stockfish/Stockfish/pull/3883

Bench: 4266621
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: Stéphane Nicolet
Date: Sat Jan 8 08:43:14 2022 +0100
Timestamp: 1641627794

Update AUTHORS and CPU contributors files

closes https://github.com/official-stockfish/Stockfish/pull/3882

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: Brad Knox
Date: Thu Jan 6 15:45:45 2022 +0100
Timestamp: 1641480345

Update copyright years

Happy New Year!

closes https://github.com/official-stockfish/Stockfish/pull/3881

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: lonfom169
Date: Sun Jan 2 17:49:44 2022 +0100
Timestamp: 1641142184

Simplify away rangeReduction

Remove rangeReduction, introduced in [#3717](https://github.com/official-stockfish/Stockfish/pull/3717),
as it seemingly doesn't bring enough ELO anymore. It might be interesting to add
new forms of reduction or tune the reduction formula in the future.

STC:
LLR: 2.95 (-2.94,2.94) <-2.25,0.25>
Total: 45008 W: 12114 L: 11972 D: 20922 Elo +1.10
Ptnml(0-2): 174, 5031, 11952, 5173, 174
https://tests.stockfishchess.org/tests/view/61d08b7b069ca917749c9f6f

LTC:
LLR: 2.94 (-2.94,2.94) <-2.25,0.25>
Total: 30792 W: 8235 L: 8086 D: 14471 Elo +1.68
Ptnml(0-2): 24, 3162, 8882, 3297, 31
https://tests.stockfishchess.org/tests/view/61d0a6ad069ca917749ca420

closes https://github.com/official-stockfish/Stockfish/pull/3878

Bench: 4048312
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: lonfom169
Date: Fri Dec 31 07:44:15 2021 +0100
Timestamp: 1640933055

Smooth out doDeeperSearch

Adjust threshold based on the difference between newDepth and LMR depth.
With more reduction, bigger fail-high is required in order to perform the deeper search.

STC:
LLR: 2.96 (-2.94,2.94) <0.00,2.50>
Total: 93576 W: 24133 L: 23758 D: 45685 Elo +1.39
Ptnml(0-2): 260, 10493, 24935, 10812, 288
https://tests.stockfishchess.org/tests/view/61cbb5cee68b2a714b6eaf09

LTC:
LLR: 2.94 (-2.94,2.94) <0.50,3.00>
Total: 109280 W: 28198 L: 27754 D: 53328 Elo +1.41
Ptnml(0-2): 60, 11225, 31637, 11647, 71
https://tests.stockfishchess.org/tests/view/61cc03fee68b2a714b6ec091

closes https://github.com/official-stockfish/Stockfish/pull/3877

Bench: 4464723
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: Stéphane Nicolet
Date: Thu Dec 30 11:59:23 2021 +0100
Timestamp: 1640861963

Tweak optimism with complexity

This patch increases the optimism bonus for "complex positions", where the
complexity is measured as the absolute value of the difference between material
and the sophisticated NNUE evaluation (idea by Joost VandeVondele).

Also rename some variables in evaluate() while there.

passed STC:
LLR: 2.94 (-2.94,2.94) <0.00,2.50>
Total: 88392 W: 23150 L: 22781 D: 42461 Elo +1.45
Ptnml(0-2): 318, 9961, 23257, 10354, 306
https://tests.stockfishchess.org/tests/view/61cbbedee68b2a714b6eb110

passed LTC:
LLR: 2.93 (-2.94,2.94) <0.50,3.00>
Total: 37848 W: 10043 L: 9766 D: 18039 Elo +2.54
Ptnml(0-2): 26, 3815, 10961, 4100, 22
https://tests.stockfishchess.org/tests/view/61cc0cc3e68b2a714b6ec28c

Closes https://github.com/official-stockfish/Stockfish/pull/3875
Follow-up from https://github.com/official-stockfish/Stockfish/commit/a5a89b27c8e3225fb453d603bc4515d32bb351c3

Bench: 4125221
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: bmc4
Date: Mon Dec 27 16:43:44 2021 +0100
Timestamp: 1640619824

Don't direct prune a move if it's a retake

STC:
LLR: 2.94 (-2.94,2.94) <0.00,2.50>
Total: 36304 W: 9499 L: 9226 D: 17579 Elo +2.61
Ptnml(0-2): 96, 4102, 9508, 4325, 121
https://tests.stockfishchess.org/tests/view/61c7069ae68b2a714b6dca27

LTC:
LLR: 2.95 (-2.94,2.94) <0.50,3.00>
Total: 93824 W: 24478 L: 24068 D: 45278 Elo +1.52
Ptnml(0-2): 70, 9644, 27082, 10038, 78
https://tests.stockfishchess.org/tests/view/61c725fee68b2a714b6dcfa2

closes https://github.com/official-stockfish/Stockfish/pull/3871

Bench: 4106806
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: Wed Dec 22 11:02:34 2021 +0100
Timestamp: 1640167354

Update default net to nn-ac07bd334b62.nnue

Trained with essentially the same data as provided and used by Farseer (mbabigian)
for the previous master net.

T60T70wIsRightFarseerT60T74T75T76.binpack (99GB):
['T60T70wIsRightFarseer.binpack', 'farseerT74.binpack', 'farseerT75.binpack', 'farseerT76.binpack']
using the trainer branch tweakLR1PR (https://github.com/glinscott/nnue-pytorch/pull/158) and
`--gpus 1 --threads 4 --num-workers 4 --batch-size 16384 --progress_bar_refresh_rate 300 --smart-fen-skipping --random-fen-skipping 12 --features=HalfKAv2_hm^ --lambda=1.00` options

passed STC:
LLR: 2.95 (-2.94,2.94) <0.00,2.50>
Total: 108280 W: 28042 L: 27636 D: 52602 Elo +1.30
Ptnml(0-2): 328, 12382, 28401, 12614, 415
https://tests.stockfishchess.org/tests/view/61bcd8c257a0d0f327c34fbd

passed LTC:
LLR: 2.94 (-2.94,2.94) <0.50,3.00>
Total: 259296 W: 66974 L: 66175 D: 126147 Elo +1.07
Ptnml(0-2): 146, 27096, 74452, 27721, 233
https://tests.stockfishchess.org/tests/view/61bda70957a0d0f327c37817

closes https://github.com/official-stockfish/Stockfish/pull/3870

Bench: 4633875
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: Michael Chaly
Date: Wed Dec 22 08:18:35 2021 +0100
Timestamp: 1640157515

Fall back to NNUE if classical evaluation is much lower than threshold

The idea is that if classical eval returns a value much lower than the threshold of
its usage it most likely means that position isn't that simple
so we need the more precise NNUE evaluation.

passed STC:
https://tests.stockfishchess.org/tests/view/61bf3e7557a0d0f327c3c47a
LLR: 2.95 (-2.94,2.94) <0.00,2.50>
Total: 108072 W: 28007 L: 27604 D: 52461 Elo +1.30
Ptnml(0-2): 352, 12147, 28650, 12520, 367

passed LTC:
https://tests.stockfishchess.org/tests/view/61c0581657a0d0f327c3fa0c
LLR: 2.95 (-2.94,2.94) <0.50,3.00>
Total: 155096 W: 40392 L: 39841 D: 74863 Elo +1.23
Ptnml(0-2): 88, 15983, 44843, 16558, 76

closes https://github.com/official-stockfish/Stockfish/pull/3869

bench 4310422
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: bmc4
Date: Tue Dec 21 13:47:57 2021 +0100
Timestamp: 1640090877

Update Elo estimates for terms in search

This updates estimates from 2yr ago #2401, and adds missing terms.
All tests run at 10+0.1 (STC), 20000 games, error bars +- 1.8 Elo, book 8moves_v3.png.

A table of Elo values with the links to the corresponding tests can be found at the PR

closes https://github.com/official-stockfish/Stockfish/pull/3868

Non-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: bmc4
Date: Tue Dec 21 13:42:33 2021 +0100
Timestamp: 1640090553

Remove Capture history pruning

Fixed number of games. (book: 8moves_v3.png):
ELO: -0.69 +-1.8 (95%) LOS: 22.1%
Total: 20000 W: 1592 L: 1632 D: 16776 Elo -0.69
Ptnml(0-2): 44, 1194, 7566, 1150, 46
https://tests.stockfishchess.org/tests/view/61bb8eb657a0d0f327c30ce8

STC:
LLR: 2.94 (-2.94,2.94) <-2.25,0.25>
Total: 139976 W: 36039 L: 36036 D: 67901 Elo +0.01
Ptnml(0-2): 435, 16138, 36885, 16049, 481
https://tests.stockfishchess.org/tests/view/61be731857a0d0f327c39ea2

LTC:
LLR: 2.95 (-2.94,2.94) <-2.25,0.25>
Total: 70656 W: 18284 L: 18189 D: 34183 Elo +0.47
Ptnml(0-2): 34, 7317, 20529, 7416, 32
https://tests.stockfishchess.org/tests/view/61bf39b657a0d0f327c3c37b

closes https://github.com/official-stockfish/Stockfish/pull/3867

bench: 4281737
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: bmc4
Date: Tue Dec 21 13:40:57 2021 +0100
Timestamp: 1640090457

Remove Capture Extension

This revert the patch #3692, probably can be simplified after the introduction of #3838.

Fixed-game test:
ELO: -1.41 +-1.8 (95%) LOS: 5.9%
Total: 20000 W: 1552 L: 1633 D: 16815 Elo -1.41
Ptnml(0-2): 38, 1242, 7517, 1169, 34
https://tests.stockfishchess.org/tests/view/61bc1a2057a0d0f327c32a3c

STC:
LLR: 2.94 (-2.94,2.94) <-2.25,0.25>
Total: 44528 W: 11619 L: 11478 D: 21431 Elo +1.10
Ptnml(0-2): 146, 5020, 11771, 5201, 126
https://tests.stockfishchess.org/tests/view/61bc638c57a0d0f327c338fe

LTC:
LLR: 2.94 (-2.94,2.94) <-2.25,0.25>
Total: 34136 W: 8847 L: 8704 D: 16585 Elo +1.46
Ptnml(0-2): 23, 3475, 9925, 3626, 19
https://tests.stockfishchess.org/tests/view/61bcb24257a0d0f327c34813

closes https://github.com/official-stockfish/Stockfish/pull/3863

Bench: 4054695
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: Stéphane Nicolet
Date: Sun Dec 19 15:44:01 2021 +0100
Timestamp: 1639925041

Simplification in evaluate_nnue.cpp

Removes the test on non-pawn-material before applying the positional/materialistic bonus.

Passed STC:
LLR: 2.94 (-2.94,2.94) <-2.25,0.25>
Total: 46904 W: 12197 L: 12059 D: 22648 Elo +1.02
Ptnml(0-2): 170, 5243, 12479, 5399, 161
https://tests.stockfishchess.org/tests/view/61be57cf57a0d0f327c3999d

Passed LTC:
LLR: 2.95 (-2.94,2.94) <-2.25,0.25>
Total: 18760 W: 4958 L: 4790 D: 9012 Elo +3.11
Ptnml(0-2): 14, 1942, 5301, 2108, 15
https://tests.stockfishchess.org/tests/view/61bed1fb57a0d0f327c3afa9

closes https://github.com/official-stockfish/Stockfish/pull/3866

Bench: 4826206
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: George Sobala
Date: Sun Dec 19 11:43:18 2021 +0100
Timestamp: 1639910598

Fixes build failure on Apple M1 Silicon

This pull request selectively avoids `-mdynamic-no-pic` for gcc on Apple Silicon
(there was no problem with the default clang compiler).

fixes https://github.com/official-stockfish/Stockfish/issues/3847
closes https://github.com/official-stockfish/Stockfish/pull/3850

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: Michael Chaly
Date: Sun Dec 19 08:03:41 2021 +0100
Timestamp: 1639897421

Reintroduce futility pruning for captures

This is a reintroduction of an idea that was simplified away approximately 1 year ago.
There are some tweaks to it :
a) exclude promotions;
b) exclude Pv Nodes from it - Pv Nodes logic for captures is really different from non Pv nodes so it makes a lot of sense;
c) use a big grain of capture history - idea is taken from my recent patches in futility pruning.

passed STC
https://tests.stockfishchess.org/tests/view/61bd90f857a0d0f327c373b7
LLR: 2.96 (-2.94,2.94) <0.00,2.50>
Total: 86640 W: 22474 L: 22110 D: 42056 Elo +1.46
Ptnml(0-2): 268, 9732, 22963, 10082, 275

passed LTC
https://tests.stockfishchess.org/tests/view/61be094457a0d0f327c38aa3
LLR: 2.95 (-2.94,2.94) <0.50,3.00>
Total: 23240 W: 6079 L: 5838 D: 11323 Elo +3.60
Ptnml(0-2): 14, 2261, 6824, 2512, 9

https://github.com/official-stockfish/Stockfish/pull/3864

bench 4493723
see source

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