Add a rank based bonus for blocked pawns.
authorStefan Geschwentner <stgeschwentner@gmail.com>
Mon, 6 Jul 2020 07:30:23 +0000 (09:30 +0200)
committerJoost VandeVondele <Joost.VandeVondele@gmail.com>
Mon, 6 Jul 2020 15:56:18 +0000 (17:56 +0200)
commit7225d254f90c7b9d64d4adf85ec2d319c6cf75a0
tree33b17e0173b7711852a87ec9f239ed1350140e57
parentc5b2a92cd17c65a639ec6739dd511767f65e188d
Add a rank based bonus for blocked pawns.

Fix for overevaluated blocked pawns on the 5th and 6th rank.
This is a rewrite of the original idea that uses only two parameters.
Thanks to rocky640 for pointing this out.

STC:
LLR: 2.94 (-2.94,2.94) {-0.50,1.50}
Total: 50800 W: 9707 L: 9446 D: 31647
Ptnml(0-2): 831, 5851, 11822, 6018, 878
https://tests.stockfishchess.org/tests/view/5f00b4f359f6f03532894304

LTC:
LLR: 2.93 (-2.94,2.94) {0.25,1.75}
Total: 52064 W: 6477 L: 6167 D: 39420
Ptnml(0-2): 331, 4628, 15834, 4878, 361
https://tests.stockfishchess.org/tests/view/5f0115fe59f6f03532894345

closes https://github.com/official-stockfish/Stockfish/pull/2794

Bench: 4882833
src/pawns.cpp