larger reduction of depth if no TT entry is found, and go in qsearch as needed.
stc:
https://tests.stockfishchess.org/tests/view/
629dfacd593a4a9b6482db72
LLR: 2.93 (-2.94,2.94) <0.00,2.50>
Total: 31920 W: 8591 L: 8322 D: 15007
Ptnml(0-2): 127, 3551, 8376, 3738, 168
ltc:
https://tests.stockfishchess.org/tests/view/
629e304e593a4a9b6482e451
LLR: 2.95 (-2.94,2.94) <0.50,3.00>
Total: 17488 W: 4842 L: 4614 D: 8032
Ptnml(0-2): 13, 1670, 5151, 1896, 14
closes https://github.com/official-stockfish/Stockfish/pull/4056
Bench:
5870283
- // Step 11. If the position is not in TT, decrease depth by 2 or 1 depending on node type (~3 Elo)
- if ( PvNode
- && depth >= 3
+ // Step 11. If the position is not in TT, decrease depth by 3.
+ // Use qsearch if depth is equal or below zero (~4 Elo)
+ if ( PvNode
- if ( cutNode
- && depth >= 8
+ if (depth <= 0)
+ return qsearch<PV>(pos, ss, alpha, beta);
+
+ if ( cutNode
+ && depth >= 8