A combo of parameters tweaks
authorStéphane Nicolet <cassio@free.fr>
Wed, 20 May 2020 15:06:42 +0000 (17:06 +0200)
committerStéphane Nicolet <cassio@free.fr>
Thu, 21 May 2020 12:05:07 +0000 (14:05 +0200)
commit6c1af710d16c6a358cc09c51a133120605c39e44
treeb3d078590895bd3484f20b737bb5ec866004bdca
parent20ceeac8b3a3bd13a64d6a224ef190d6cdd94f63
A combo of parameters tweaks

This patch is a combinaison of two recent parameters tweaks which had
failed narrowly (yellow) at long time control:

• improvement in move ordering during search by softening the distinction
  between bad captures and good captures during move generation, leading
  to improved awareness of Stockfish of potential piece sacrifices (idea
  by Rahul Dsilva)
• increase in the weight of pawns in the "initiative" part of the evaluation
  function. With this change Stockfish should have more incentive to exchange
  pawns when losing, and to keep pawns when winning.

STC:
LLR: 2.93 (-2.94,2.94) {-0.50,1.50}
Total: 10704 W: 2178 L: 1974 D: 6552
Ptnml(0-2): 168, 1185, 2464, 1345, 190
https://tests.stockfishchess.org/tests/view/5ec5553b377121ac09e1023d

LTC:
LLR: 2.94 (-2.94,2.94) {0.25,1.75}
Total: 60592 W: 7835 L: 7494 D: 45263
Ptnml(0-2): 430, 5514, 18086, 5817, 449
https://tests.stockfishchess.org/tests/view/5ec55ca2377121ac09e10249

Closes https://github.com/official-stockfish/Stockfish/pull/2691

Bench: 4519117
src/evaluate.cpp
src/movepick.cpp