Introduce concept of double pawn protection.
authorVizvezdenec <Vizvezdenec@gmail.com>
Sun, 2 Dec 2018 19:18:14 +0000 (20:18 +0100)
committerStéphane Nicolet <cassio@free.fr>
Sun, 2 Dec 2018 19:18:51 +0000 (20:18 +0100)
commit9dc6d270fc207d6715578b57a1cdf655527ec5fe
tree61554be0f7164e87c985094c6e1633475674bdbc
parent982fd9c8bce85d4cd8dca32759587d7606385e0e
Introduce concept of double pawn protection.

Exclude doubly protected by pawns squares when calculating attackers on
king ring. Idea of this patch is not to count attackers if they attack
only squares that are protected by two pawns.

STC
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 70040 W: 15476 L: 15002 D: 39562
http://tests.stockfishchess.org/tests/view/5c0354860ebc5902bcee1106

LTC
LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 16530 W: 2795 L: 2607 D: 11128
http://tests.stockfishchess.org/tests/view/5c0385080ebc5902bcee14b5

This is third king safety patch in recent times so we probably need
retuning of king safety parameters.

Bench: 3057978
src/bitboard.h
src/evaluate.cpp