In endgame it's better to have pawns on both wings.
So give a bonus according to file distance between left
and right outermost pawns.
Passed both short TC
LLR: 2.97 (-2.94,2.94) [-1.50,4.50]
Total: 39073 W: 7749 L: 7536 D: 23788
And long TC
LLR: 2.96 (-2.94,2.94) [0.00,6.00]
Total: 6149 W: 1040 L: 910 D: 4199
bench:
7665034
S( 0, 0), S( 6, 13), S(6,13), S(14,29),
S(34,68), S(83,166), S(0, 0), S( 0, 0) };
S( 0, 0), S( 6, 13), S(6,13), S(14,29),
S(34,68), S(83,166), S(0, 0), S( 0, 0) };
+ // Bonus for file distance of the two outermost pawns
+ const Score PawnsFileSpan = S(0, 10);
+
// Weakness of our pawn shelter in front of the king indexed by [rank]
const Value ShelterWeakness[RANK_NB] =
{ V(100), V(0), V(27), V(73), V(92), V(101), V(101) };
// Weakness of our pawn shelter in front of the king indexed by [rank]
const Value ShelterWeakness[RANK_NB] =
{ V(100), V(0), V(27), V(73), V(92), V(101), V(101) };
+ // In endgame it's better to have pawns on both wings. So give a bonus according
+ // to file distance between left and right outermost pawns.
+ if (pos.count<PAWN>(Us) > 1)
+ {
+ b = ~e->semiopenFiles[Us] & 0xFF;
+ value += PawnsFileSpan * int(msb(b) - lsb(b));
+ }
+