Count passed pawns in asymmetry measure
authorStéphane Nicolet <cassio@free.fr>
Sun, 25 Feb 2018 12:12:09 +0000 (13:12 +0100)
committerStéphane Nicolet <cassio@free.fr>
Sun, 25 Feb 2018 12:12:23 +0000 (13:12 +0100)
commit2e21aba8d937bdf5eb0eedeac99ac2c2553e9d0d
treea32930168d839f4c0bba909c9ad9a8fac2a5d8d7
parent8dd6875240e05dbcc1fb6467ffb11ad360aa474c
Count passed pawns in asymmetry measure

The previous asymmetry measure of the pawn structure only used to
consider the number of pawns on semi-opened files in the postions.
With this patch we also increase the measure by the number of passed
pawns for both players.

STC:
LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 13146 W: 3038 L: 2840 D: 7268
http://tests.stockfishchess.org/tests/view/5a91dd0c0ebc590297cc877e

LTC:
LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 27776 W: 4771 L: 4536 D: 18469
http://tests.stockfishchess.org/tests/view/5a91fdd50ebc590297cc879b

How to continue from there: Stockfish will now evaluate more positions
with passed pawns, so tuning the passed pawns values may bring Elo.
The patch also has consequences on the initiative term.

Bench: 5302866
src/pawns.cpp