Remove lmrDepth restriction on quiet see pruning
authorDU-jdto <jadto@outlook.com>
Wed, 13 Jun 2018 05:22:52 +0000 (15:22 +1000)
committerStéphane Nicolet <cassio@free.fr>
Wed, 13 Jun 2018 19:52:53 +0000 (21:52 +0200)
commita834bfe8332adcb0dfc1fd280f1f9d8bbce86266
tree5406a4d14aebb610a888ffd650e7391b44809c13
parent6c36e6519393b2ccfb111f603f793f38aa0f1963
Remove lmrDepth restriction on quiet see pruning

And tweak the threshold value. With this threshold and the current piece
values, this permits see pruning on quiets to be done up to an lmrDepth
of 9 (beyond that the threshold is below -QueenValueMg and see_ge will
pass unconditionally).

STC:
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 110316 W: 24612 L: 24667 D: 61037
http://tests.stockfishchess.org/tests/view/5b20aa760ebc5902ab9c9c1d

LTC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 17352 W: 2968 L: 2842 D: 11542
http://tests.stockfishchess.org/tests/view/5b20cf1e0ebc5902ab9c9fb6

Closes https://github.com/official-stockfish/Stockfish/pull/1651

Bench: 5069074
src/search.cpp