Stockfish Download.

[APOCALYPSE]

Author: Linmiao Xu
Date: Sat Jul 15 09:16:09 2023 +0200
Timestamp: 1689405369

Reintroduce nnue eval pawn count multipliers again

With separate multipliers for nnue eval and optimism scaling.
This patch used 4 out of 7 params tuned with spsa at 30+0.3
using this tuning config:

Value LazyThreshold1 = Value(3622);
Value LazyThreshold2 = Value(1962);
int psqThresh = 2048;
int nnueNpmBase = 945;
int nnuePcMult = 0;
int optNpmBase = 150;
int optPcMult = 0;
TUNE(SetRange(3322, 3922), LazyThreshold1);
TUNE(SetRange(1662, 2262), LazyThreshold2);
TUNE(SetRange(1748, 2348), psqThresh);
TUNE(SetRange(745, 1145), nnueNpmBase);
TUNE(SetRange(-16, 16), nnuePcMult);
TUNE(SetRange(0, 300), optNpmBase);
TUNE(SetRange(-16, 16), optPcMult);

Passed STC:
https://tests.stockfishchess.org/tests/ ... 745c60ed07
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 173632 W: 44417 L: 43903 D: 85312 Elo +1.03
Ptnml(0-2): 547, 20025, 45068, 20719, 457

Passed LTC:
https://tests.stockfishchess.org/tests/ ... 745c6136af
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 277644 W: 70955 L: 70147 D: 136542 Elo +1.01
Ptnml(0-2): 193, 29902, 77787, 30784, 156

closes https://github.com/official-stockfish/S ... /pull/4681

bench 1556301

[APOCALYPSE]

Author: Michael Chaly
Date: Sun Jul 16 15:18:41 2023 +0200
Timestamp: 1689513521

Remove improvement variable

No longer used in a meaningful way.
Improve comments.

Closes https://github.com/official-stockfish/S ... /pull/4688

No functional change

[APOCALYPSE]

Author: Joost VandeVondele
Date: Sun Jul 16 17:47:25 2023 +0200
Timestamp: 1689522445

Deprecate the x86-64-modern arch

Explicitly describe the architecture as deprecated,
it remains available as its current alias x86-64-sse41-popcnt

CPUs that support just this instruction set are now years old,
any few years old Intel or AMD CPU supports x86-64-avx2. However,
naming things 'modern' doesn't age well, so instead use explicit names.

Adjust CI accordingly. Wiki, fishtest, downloader done as well.

closes https://github.com/official-stockfish/S ... /pull/4691

No functional change.

[APOCALYPSE]

Author: Joost VandeVondele
Date: Sun Jul 16 22:27:13 2023 +0200
Timestamp: 1689539233

Switch to macos 13 for CI

allows for building x86-64-avx2 and x86-64-bmi2 binaries for mac

install coreutils
show hardware capabilities as seen by the compilers
move some tests from sse41 to avx2 as platforms support it

closes https://github.com/official-stockfish/S ... /pull/4692

No functional change

[APOCALYPSE]

Author: rn5f107s2
Date: Tue Jul 18 08:10:11 2023 +0200
Timestamp: 1689660611

Removes a few Bitboards and functions

No longer used

closes https://github.com/official-stockfish/S ... /pull/4695

No functional change

[APOCALYPSE]

Author: Michael Chaly
Date: Wed Jul 19 21:40:38 2023 +0200
Timestamp: 1689795638

Do more futility pruning for cutNodes that are not in TT

This is somewhat similar to IIR for cutnodes but instead of reducing
depth for cutnodes that don't have tt move we reduce margin multiplier
in futility pruning for cutnodes that are not in TT.

Passed STC:
https://tests.stockfishchess.org/tests/ ... 7b95734c5b
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 75552 W: 19404 L: 19029 D: 37119 Elo +1.72
Ptnml(0-2): 233, 8806, 19378, 9071, 288

Passed LTC:
https://tests.stockfishchess.org/tests/ ... 7b95736516
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 104988 W: 27152 L: 26697 D: 51139 Elo +1.51
Ptnml(0-2): 41, 11259, 29446, 11700, 48

closes https://github.com/official-stockfish/S ... /pull/4700

bench 1727577

[APOCALYPSE]

Author: Stefan Geschwentner
Date: Mon Jul 24 02:23:43 2023 +0200
Timestamp: 1690158223

Simplify TT cutoff

Remove the exact bound condition from TT depth check.

STC:
https://tests.stockfishchess.org/tests/ ... 7b957359e9
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 332928 W: 84895 L: 85003 D: 163030 Elo -0.11
Ptnml(0-2): 1242, 39200, 85604, 39260, 1158

LTC:
https://tests.stockfishchess.org/tests/ ... 650abac0b6
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 92946 W: 23628 L: 23482 D: 45836 Elo +0.55
Ptnml(0-2): 38, 10033, 26192, 10165, 45

closes https://github.com/official-stockfish/S ... /pull/4702

Bench: 1601764

[APOCALYPSE]

Author: Stephen Touset
Date: Tue Jul 25 00:13:38 2023 +0200
Timestamp: 1690236818

Remove Zobrist::noPawns

Zobrist::noPawns is no longer used.

closes https://github.com/official-stockfish/S ... /pull/4344

no functional change

[APOCALYPSE]

Author: FauziAkram
Date: Tue Jul 25 16:43:35 2023 +0200
Timestamp: 1690296215

Simplify one multicut extension

Simplify away the ttValue <= alpha extension in the multicut block.

Passed STC:
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 318336 W: 81307 L: 81398 D: 155631 Elo -0.10
Ptnml(0-2): 1088, 37291, 82469, 37264, 1056
https://tests.stockfishchess.org/tests/ ... 650abad61d

Passed LTC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 89388 W: 22925 L: 22775 D: 43688 Elo +0.58
Ptnml(0-2): 34, 9635, 25210, 9777, 38
https://tests.stockfishchess.org/tests/ ... 650abb29cb

closes https://github.com/official-stockfish/S ... /pull/4709

bench: 1604592

[APOCALYPSE]

Author: Stéphane Nicolet
Date: Fri Jul 28 23:38:49 2023 +0200
Timestamp: 1690580329

Improve some comments

- clarify the examples for the bench command
- typo in search.cpp

closes https://github.com/official-stockfish/S ... /pull/4710

No functional change