Principal variation depth late move reduction extension simplification.
stc:
https://tests.stockfishchess.org/tests/view/
6285a1d19d18a78568e7fa24
LLR: 2.94 (-2.94,2.94) <-2.25,0.25>
Total: 428536 W: 113433 L: 113851 D: 201252
Ptnml(0-2): 1671, 48606, 114090, 48272, 1629
ltc:
https://tests.stockfishchess.org/tests/view/
62871d20375cdc5de8cf5db3
LLR: 2.95 (-2.94,2.94) <-2.25,0.25>
Total: 56792 W: 15123 L: 15011 D: 26658
Ptnml(0-2): 42, 5681, 16825, 5819, 29
closes https://github.com/official-stockfish/Stockfish/pull/4028
bench:
6501437
// deeper than the first move (this may lead to hidden double extensions).
int deeper = r >= -1 ? 0
: moveCount <= 4 ? 2
// deeper than the first move (this may lead to hidden double extensions).
int deeper = r >= -1 ? 0
: moveCount <= 4 ? 2
- : PvNode && depth > 4 ? 1
: cutNode && moveCount <= 8 ? 1
: 0;
: cutNode && moveCount <= 8 ? 1
: 0;