Tune null move pruning
authorStefan Geschwentner <locutus2@users.noreply.github.com>
Thu, 10 May 2018 10:27:14 +0000 (12:27 +0200)
committerSt├ęphane Nicolet <cassio@free.fr>
Thu, 10 May 2018 10:28:18 +0000 (12:28 +0200)
commit76d4a80084f2ff61b0ea433ac829914370736b5e
tree0628e5a9c622ac6bd607c00b5d65d7aa6993d720
parentfc0a1f37cf2029af3d35221423da7ac512afbf88
Tune null move pruning

Use a lower stat score threshold of 22500.

Failed yellow at STC after many games (~0.92 Elo):
LLR: -2.96 (-2.94,2.94) [0.00,4.00]
Total: 73978 W: 14947 L: 14834 D: 44197
http://tests.stockfishchess.org/tests/view/5af2deec0ebc5968e6523f80

But scales good and passed LTC:
LLR: 2.96 (-2.94,2.94) [0.00,4.00]
Total: 23147 W: 3453 L: 3237 D: 16457
http://tests.stockfishchess.org/tests/view/5af3cf820ebc5968e6524022

Closes https://github.com/official-stockfish/Stockfish/pull/1591

Bench: 4777674
src/search.cpp