Expand maximum allowed eval by 50% in futility pruning, above the VALUE_KNOWN_WIN.
STC:
LLR: 2.95 (-2.94,2.94) <-0.50,2.50>
Total: 128208 W: 32534 L: 32192 D: 63482
Ptnml(0-2): 298, 13484, 36216, 13790, 316
https://tests.stockfishchess.org/tests/view/
6179c069a9b1d8fbcc4ee716
LTC:
LLR: 2.96 (-2.94,2.94) <0.50,3.50>
Total: 89816 W: 22645 L: 22265 D: 44906
Ptnml(0-2): 41, 8404, 27650, 8760, 53
https://tests.stockfishchess.org/tests/view/
617ad728f411ea45cc39f895
closes https://github.com/official-stockfish/Stockfish/pull/3767
bench:
6804175
if ( !PvNode
&& depth < 9
&& eval - futility_margin(depth, improving) >= beta
if ( !PvNode
&& depth < 9
&& eval - futility_margin(depth, improving) >= beta
- && eval < VALUE_KNOWN_WIN) // Do not return unproven wins
+ && eval < 15000) // 50% larger than VALUE_KNOWN_WIN, but smaller than TB wins.
return eval;
// Step 8. Null move search with verification search (~40 Elo)
return eval;
// Step 8. Null move search with verification search (~40 Elo)