Commit Graph
4 Commits
Author SHA1 Message Date
rn5f107s2andDisservin e860f620aa Reduce futility_margin further when improving
The idea of this is to unroll the futility_margin calculation to allow
for the improving flag to have a greater effect on the futility margin.
The current factor is 1.5 instead of the previous 1 resulting in a
deduction of an extra margin/2 from futilit_margin if improving. The
chosen value was not tuned, meaning that there is room for tweaking it.
This patch is partially inspired by @Vizvezdenec, who, although quite
different in execution, tested another idea where the futility_margin is
lowered further when improving [1].

[1]: (first take) https://tests.stockfishchess.org/tests/view/65a56b1879aa8af82b97164b

Passed STC:
https://tests.stockfishchess.org/tests/live_elo/65a8bfc179aa8af82b974e3c
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 161152 W: 41321 L: 40816 D: 79015
Ptnml(0-2): 559, 19030, 40921, 19479, 587

Passed rebased LTC:
https://tests.stockfishchess.org/tests/live_elo/65a8b9ef79aa8af82b974dc0
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 96024 W: 24172 L: 23728 D: 48124
Ptnml(0-2): 56, 10598, 26275, 11012, 71

closes https://github.com/official-stockfish/Stockfish/pull/5000

Bench: 1281703
2024-01-21 12:42:07 +01:00
rn5f107s2andStéphane Nicolet 65ece7d985 Malus during move ordering for putting pieces en prise
The original idea is the reverse of a previous patch [1] which added bonuses
in our move picker to moves escaping threats. In this patch, in addition to
bonuses for evading threats, we apply penalties to moves moving to threatened
squares.

Further tweaks of that basic idea resulted in this specific version which
further increases the penalty of moves moving to squares threatend depending
on the piece threatening it. So for example a queen moving to a square attacked
by a pawn would receive a larger penalty than a queen moving to square attacked
by a rook.

[1]: https://github.com/official-stockfish/Stockfish/commit/08e0f52b77edb929989c68c49e954b9bc5d7d67e

--------

Passed STC:
https://tests.stockfishchess.org/tests/live_elo/64c11269dc56e1650abb935d
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 95552 W: 24654 L: 24250 D: 46648
Ptnml(0-2): 322, 11098, 24562, 11442, 352

Passed LTC:
https://tests.stockfishchess.org/tests/live_elo/64c2004ddc56e1650abba8b3
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 190230 W: 48806 L: 48178 D: 93246
Ptnml(0-2): 90, 20439, 53453, 21019, 114

-------

closes https://github.com/official-stockfish/Stockfish/pull/4711

Bench: 1350831
2023-07-29 00:56:26 +02:00
rn5f107s2andJoost VandeVondele 42d28424bc Removes a few Bitboards and functions
No longer used

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

No functional change
2023-07-18 08:10:11 +02:00
rn5f107s2andJoost VandeVondele 95ce443aaa simplified gives check castling
tested verifying perft and bench is unchanged
on a larger set of epds for both standard and FRC chess.

Passed non-regression STC:
https://tests.stockfishchess.org/tests/live_elo/648587be65ffe077ca123d78
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 153632 W: 41015 L: 40928 D: 71689
Ptnml(0-2): 377, 16077, 43816, 16174, 372

closes https://github.com/official-stockfish/Stockfish/pull/4628

No functional change
2023-07-03 18:54:22 +02:00