At expected cut nodes allow at least one ply deeper LMR search for the first seventh moves.
STC:
LLR: 2.93 (-2.94,2.94) <-0.50,2.50>
Total: 42880 W: 10964 L: 10738 D: 21178
Ptnml(0-2): 105, 4565, 11883, 4773, 114
https://tests.stockfishchess.org/tests/view/
6179abd7a9b1d8fbcc4ee6f4
LTC:
LLR: 2.93 (-2.94,2.94) <0.50,3.50>
Total: 66872 W: 16930 L: 16603 D: 33339
Ptnml(0-2): 36, 6509, 20024, 6826, 41
https://tests.stockfishchess.org/tests/view/
617a30fb2fbca9ca65972b5e
closes https://github.com/official-stockfish/Stockfish/pull/3770
Bench:
6295536
// In general we want to cap the LMR depth search at newDepth. But if reductions
// are really negative and movecount is low, we allow this move to be searched
// deeper than the first move (this may lead to hidden double extensions).
// In general we want to cap the LMR depth search at newDepth. But if reductions
// are really negative and movecount is low, we allow this move to be searched
// deeper than the first move (this may lead to hidden double extensions).
- int deeper = r >= -1 ? 0
- : moveCount <= 5 ? 2
- : PvNode && depth > 6 ? 1
- : 0;
+ int deeper = r >= -1 ? 0
+ : moveCount <= 5 ? 2
+ : PvNode && depth > 6 ? 1
+ : cutNode && moveCount <= 7 ? 1
+ : 0;
Depth d = std::clamp(newDepth - r, 1, newDepth + deeper);
Depth d = std::clamp(newDepth - r, 1, newDepth + deeper);