kate/BadFish
1
0
Fork 0
mirror of https://github.com/sockspls/badfish synced 2025-04-29 16:23:09 +00:00
Code Issues Releases Wiki Activity

Tweak quiet move bonus

Browse source 
Improving quiet move bonus by replacing bestvalue and alpha comparison, with
checking the statScore of the previous search step instead.

Inspired by @locutus2

Passed STC:
https://tests.stockfishchess.org/tests/view/657f22fb893104ee25b614e8
LLR: 2.96 (-2.94,2.94) <0.00,2.00>
Total: 51296 W: 13121 L: 12774 D: 25401
Ptnml(0-2): 225, 5986, 12868, 6355, 214

Passed LTC:
https://tests.stockfishchess.org/tests/view/658024a2893104ee25b62587
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 82758 W: 20606 L: 20189 D: 41963
Ptnml(0-2): 51, 9149, 22555, 9580, 44

closes https://github.com/official-stockfish/Stockfish/pull/4930

Bench: 1312822
This commit is contained in:
FauziAkram 2023-12-20 14:26:11 +03:00 • committed by Disservin
parent 358a853790
commit fbdf5d94a9
1 changed files with 2 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

4
src/search.cpp
View file

@ -748,7 +748,7 @@ Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth, boo
// Use static evaluation difference to improve quiet move ordering (~4 Elo)
if (is_ok((ss - 1)->currentMove) && !(ss - 1)->inCheck && !priorCapture)
{
int bonus = std::clamp(-13 * int((ss - 1)->staticEval + ss->staticEval), -1555, 1452);
int bonus = std::clamp(-13 * int((ss - 1)->staticEval + ss->staticEval), -1652, 1546);
thisThread->mainHistory[~us][from_to((ss - 1)->currentMove)] << bonus;
if (type_of(pos.piece_on(prevSq)) != PAWN && type_of((ss - 1)->currentMove) != PROMOTION)
thisThread->pawnHistory[pawn_structure(pos)][pos.piece_on(prevSq)][prevSq] << bonus / 4;
@ -1344,7 +1344,7 @@ moves_loop: // When in check, search starts here
// Bonus for prior countermove that caused the fail low
else if (!priorCapture && prevSq != SQ_NONE)
{
int bonus = (depth > 6) + (PvNode || cutNode) + (bestValue < alpha - 656)
int bonus = (depth > 6) + (PvNode || cutNode) + ((ss - 1)->statScore < -18782)
+ ((ss - 1)->moveCount > 10);
update_continuation_histories(ss - 1, pos.piece_on(prevSq), prevSq,
stat_bonus(depth) * bonus);