Adjust singular extension search depth
authorVizvezdenec <Vizvezdenec@gmail.com>
Fri, 20 Mar 2020 09:12:56 +0000 (12:12 +0300)
committerJoost VandeVondele <Joost.VandeVondele@gmail.com>
Fri, 20 Mar 2020 20:07:37 +0000 (21:07 +0100)
commit6ecab03dee15fe30bc0237919180a2e51e0ce4b1
treeeb121b9e57aa9411fecc1bc0dae921699240bad5
parentff271093139de92ebf4f4f8b8c67474e07d6a8bf
Adjust singular extension search depth

This patch applies a different singular extension search logic in case the position is ttPv && !PvNode.
It changes the depth of this search, higher for this types of nodes, and lower for other nodes.

passed STC
http://tests.stockfishchess.org/tests/view/5e72bbaae42a5c3b3ca2e75e
LLR: 2.94 (-2.94,2.94) {-0.50,1.50}
Total: 12692 W: 2608 L: 2389 D: 7695
Ptnml(0-2): 238, 1414, 2839, 1601, 254

passed LTC
http://tests.stockfishchess.org/tests/view/5e731c07e42a5c3b3ca2e770
LLR: 2.96 (-2.94,2.94) {0.25,1.75}
Total: 145716 W: 19218 L: 18626 D: 107872
Ptnml(0-2): 1100, 13605, 42899, 14111, 1143

closes https://github.com/official-stockfish/Stockfish/pull/2590

Bench: 5398277
src/search.cpp