This patch assigns negative stat bonuses for quiet moves
at pv nodes which are searched at depth greater than
this node assumes, so are extended.
Passed STC:
https://tests.stockfishchess.org/tests/view/
6426198bdb43ab2ba6f9cfa2
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 548944 W: 147287 L: 146254 D: 255403
Ptnml(0-2): 1662, 59772, 150671, 60605, 1762
Passed LTC:
https://tests.stockfishchess.org/tests/view/
642be4f177ff3301150d892d
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 93352 W: 25400 L: 24994 D: 42958
Ptnml(0-2): 44, 8817, 28547, 9225, 43
closes https://github.com/official-stockfish/Stockfish/pull/4495
bench
5044536
bestValue = delta = alpha = -VALUE_INFINITE;
beta = VALUE_INFINITE;
- optimism[us] = optimism[~us] = VALUE_ZERO;
+ optimism[WHITE] = optimism[BLACK] = VALUE_ZERO;
if (mainThread)
{
(ss+1)->pv[0] = MOVE_NONE;
value = -search<PV>(pos, ss+1, -beta, -alpha, newDepth, false);
+
+ if (moveCount > 1 && newDepth >= depth && !capture)
+ update_continuation_histories(ss, movedPiece, to_sq(move), -stat_bonus(newDepth));
}
// Step 19. Undo move