Stat score initialization: grandchildren
authorStefan Geschwentner <locutus2@users.noreply.github.com>
Tue, 27 Feb 2018 17:38:08 +0000 (18:38 +0100)
committerStéphane Nicolet <cassio@free.fr>
Tue, 27 Feb 2018 17:42:59 +0000 (18:42 +0100)
commitcccbecb6f8de4e34d8856f121760b74185987d8e
treedb5867e113c308f18d09f1d28ac89fa948b65e4b
parent1463881153a20690871086208eaf76f20041effb
Stat score initialization: grandchildren

This is the sequel of the previous patch, we now let the parent node initialize
stat score to zero once for all grandchildren.

Initialize statScore to zero for the grandchildren of the current position.
So statScore is shared between all grandchildren and only the first grandchild
starts with statScore = 0. Later grandchildren start with the last calculated
statScore of the previous grandchild. This influences the reduction rules in
LMR which are based on the statScore of parent position.

Tests results against the previous patch:

STC:
LLR: 2.96 (-2.94,2.94) [0.00,4.00]
Total: 23676 W: 5417 L: 5157 D: 13102
http://tests.stockfishchess.org/tests/view/5a9423a90ebc590297cc8a46

LTC:
LLR: 2.96 (-2.94,2.94) [0.00,4.00]
Total: 35485 W: 6168 L: 5898 D: 23419
http://tests.stockfishchess.org/tests/view/5a9435550ebc590297cc8a54

Bench: 5643520
src/search.cpp