Stockfish

[Homayoun]

[Homayoun]

Author: Muzhen Gaming
Date: Sun May 5 15:11:53 2024 +0200
Timestamp: 1714914713

VVLTC search tune

This patch is the result of two tuning stages:
1. ~32k games at 60+0.6 th8:
https://tests.stockfishchess.org/tests/ ... 6764c7f817
2. ~193k games at 80+0.8 th6, based on PR #5211:
https://tests.stockfishchess.org/tests/ ... 8aa857ca00.
Based on extensive VVLTC tuning and testing both before and after
#5211, it is observed that introduction of new extensions positively
affected the search tune results.

Passed VVLTC 70+0.7 th7 1st sprt: https://tests.stockfishchess.org/tests/ ... 0d85801409
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 18566 W: 4864 L: 4620 D: 9082 Elo +4.57
Ptnml(0-2): 0, 1608, 5827, 1844, 4

Passed VVLTC 70+0.7 th7 2nd sprt: https://tests.stockfishchess.org/tests/ ... 0d85802ab7
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 43142 W: 11141 L: 10838 D: 21163 Elo +2.44
Ptnml(0-2): 4, 3915, 13427, 4224, 1

Passed VVLTC 70+0.7 3rd sprt: https://tests.stockfishchess.org/tests/ ... 0825aa230b
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 40322 W: 10374 L: 10076 D: 19872 Elo +2.57
Ptnml(0-2): 1, 3660, 12544, 3952, 4

The first two sprts were run against passed #5211. The third sprt was
run against latest master.


Bench: 2180675

[OrgZ]

[Homayoun]

[Eduard Nemeth]

After the developers removed the following from Stockfish:

Author: cj5716
Date: Sun May 5 12:36:20 2024 +0200
Timestamp: 1714905380

Remove PSQT-only mode

Sockfish has become better again for analysis mode. One example, there are many more like this:

1r3rk1/3bpppp/1qn2P2/p2pP1P1/3P4/2PB1N2/6K1/qNBQ1R2 w - - 0 1

Compare it with the previous versions of SF dev.

Here is my newest Testset ENET-2025:
https://pixeldrain.com/u/Mr77sY5r

[ZamChess]

Thank you Eduard !

[Homayoun]

Author: Shawn Xu
Date: Thu May 9 09:02:57 2024 +0200
Timestamp: 1715238177

Simplify Away Negative Extension

This patch simplifies away the negative extension applied when the value returned by the transposition table is assumed to fail low over the value of reduced search.

Passed STC:
LLR: 2.99 (-2.94,2.94) <-1.75,0.25>
Total: 248736 W: 64293 L: 64302 D: 120141 Elo -0.01
Ptnml(0-2): 925, 29833, 62831, 29884, 895
https://tests.stockfishchess.org/tests/ ... d645f7f64a

Passed LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 254970 W: 64289 L: 64308 D: 126373 Elo -0.03
Ptnml(0-2): 110, 28428, 70422, 28421, 104
https://tests.stockfishchess.org/tests/ ... 7f7b97d4bb

closes https://github.com/official-stockfish/S ... /pull/5226

Bench: 2353057
https://abrok.eu/stockfish/

[Homayoun]

Author: mstembera
Date: Mon May 13 07:32:32 2024 +0200
Timestamp: 1715578352

Optimize update_accumulator_refresh_cache()

STC https://tests.stockfishchess.org/tests/ ... 9b286d30e6
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 178528 W: 46235 L: 45750 D: 86543 Elo +0.94
Ptnml(0-2): 505, 17792, 52142, 18363, 462

Combo of two yellow speedups
https://tests.stockfishchess.org/tests/ ... 7c63214f5c
LLR: -2.93 (-2.94,2.94) <0.00,2.00>
Total: 355744 W: 91714 L: 91470 D: 172560 Elo +0.24
Ptnml(0-2): 913, 36233, 103384, 36381, 961

https://tests.stockfishchess.org/tests/ ... e4cefc739c
LLR: -2.93 (-2.94,2.94) <0.00,2.00>
Total: 627040 W: 162001 L: 161339 D: 303700 Elo +0.37
Ptnml(0-2): 2268, 72379, 163532, 73105, 2236

closes https://github.com/official-stockfish/S ... /pull/5239

No functional change
https://abrok.eu/stockfish/

[Homayoun]

Author: Linmiao Xu
Date: Thu May 16 14:19:28 2024 +0200
Timestamp: 1715861968

Lower smallnet threshold linearly as pawn count decreases

Passed STC:
https://tests.stockfishchess.org/tests/ ... f42f89d894
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 377920 W: 97135 L: 96322 D: 184463 Elo +0.75
Ptnml(0-2): 1044, 44259, 97588, 44978, 1091

Passed LTC:
https://tests.stockfishchess.org/tests/ ... a3e93b31b3
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 169056 W: 42901 L: 42312 D: 83843 Elo +1.21
Ptnml(0-2): 58, 18538, 46753, 19115, 64

closes https://github.com/official-stockfish/S ... /pull/5252

Bench: 1991750

https://abrok.eu/stockfish/

[OrgZ]