As far as can tell, semiopenFiles are set if there is a pawn anywhere on
the file. The removed condition would be true even if the pawns were very
advanced, which doesn't make sense if we're looking for a trapped rook.
Seems the engine fairs better with this removed. My guess s that the
condition that mobility is 3 or less does this well enough.
Begs the question whether this is a mobility issue alone... not sure.
Should I do LTC test?
STC
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 13377 W: 3009 L: 2871 D: 7497
http://tests.stockfishchess.org/tests/view/
5a855be40ebc590297cc8166
Passed LTC
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 16288 W: 2813 L: 2685 D: 10790
http://tests.stockfishchess.org/tests/view/
5a8575a80ebc590297cc817e
Bench:
5006365
// Penalty when trapped by the king, even more if the king cannot castle
else if (mob <= 3)
{
- Square ksq = pos.square<KING>(Us);
+ File kf = file_of(pos.square<KING>(Us));
- if ( ((file_of(ksq) < FILE_E) == (file_of(s) < file_of(ksq)))
- && !pe->semiopen_side(Us, file_of(ksq), file_of(s) < file_of(ksq)))
+ if ((kf < FILE_E) == (file_of(s) < kf))
score -= (TrappedRook - make_score(mob * 22, 0)) * (1 + !pos.can_castle(Us));
}
}
return semiopenFiles[c] & (1 << f);
}
- int semiopen_side(Color c, File f, bool leftSide) const {
- return semiopenFiles[c] & (leftSide ? (1 << f) - 1 : ~((1 << (f + 1)) - 1));
- }
-
int pawns_on_same_color_squares(Color c, Square s) const {
return pawnsOnSquares[c][bool(DarkSquares & s)];
}