TrappedRook value and King positional tables
authorxoto10 <buylow001@gmail.com>
Mon, 9 Dec 2019 21:38:57 +0000 (21:38 +0000)
committerStéphane Nicolet <cassio@free.fr>
Tue, 10 Dec 2019 00:04:07 +0000 (01:04 +0100)
commit3ef0c3c34a00e6b13d6c96d8c2f0d8d7a6cc25a6
tree1004405a2286e28acd9527c85bd54fbb2b0a4f74
parent764b9adda6cf59719b5c9c8a75d2a2e696395709
TrappedRook value and King positional tables

Small tweak to increase the TrappedRook penalty. Nice idea by Alain Savard!

STC
LLR: 2.96 (-2.94,2.94) [-1.50,4.50]
Total: 36977 W: 8212 L: 7993 D: 20772
https://tests.stockfishchess.org/tests/view/5dee1c1e3cff9a249bb9e46d

LTC
LLR: 2.95 (-2.94,2.94) [0.00,3.50]
Total: 36395 W: 6070 L: 5795 D: 24530
https://tests.stockfishchess.org/tests/view/5dee90153cff9a249bb9e479

Closes https://github.com/official-stockfish/Stockfish/pull/2447

Bench: 5176990

-------------------------

Comments by Alain Savard:

For the record, the idea was to run an experimental tuning with disabled
castling in the hope to get more hits on the TrappedRook and the king in
the c1- f1-f2-c2 area
http://tests.stockfishchess.org/tests/view/5dec57be51219d7befdc76e1

A first interpretation of that tuning was green STC (0, 4) and yellow LTC (0, 4):
http://tests.stockfishchess.org/tests/view/5ded04bc51219d7befdc773a
http://tests.stockfishchess.org/tests/view/5ded1e7a51219d7befdc7760

Thank you @xoto for trying this. Indeed, because the tuned Kc2 and Kf2 values
were quite different, it was a good idea to try something more neutral.
src/evaluate.cpp
src/psqt.cpp