Skip to content

Commit

Permalink
Update pawn history based on static eval difference
Browse files Browse the repository at this point in the history
Use the same logic as in main history but with 1/4 multiplier.

Passed STC:
https://tests.stockfishchess.org/tests/view/653c1282cc309ae8395615bf
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 306624 W: 77811 L: 77094 D: 151719
Ptnml(0-2): 975, 36411, 77830, 37114, 982

Passed LTC:
https://tests.stockfishchess.org/tests/view/654258e2cc309ae83956818d
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 99150 W: 24681 L: 24228 D: 50241
Ptnml(0-2): 56, 11107, 26792, 11568, 52

closes #4859

bench 1330590
  • Loading branch information
Vizvezdenec authored and vondele committed Nov 3, 2023
1 parent 1cb9afb commit b4b704e
Showing 1 changed file with 2 additions and 0 deletions.
2 changes: 2 additions & 0 deletions src/search.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -745,6 +745,8 @@ Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth, boo
{
int bonus = std::clamp(-18 * int((ss - 1)->staticEval + ss->staticEval), -1812, 1812);
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;
}

// Set up the improving flag, which is true if current static evaluation is
Expand Down

0 comments on commit b4b704e

Please sign in to comment.