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Retire PawnSafePush bonus 

PawnSafePush, with the value S(5,5) proved not "necessary"
possibly due to recent changes to MobilityArea and other changes to Connected bonus.

STC:
LLR: 3.22 (-2.94,2.94) [-3.00,1.00]
Total: 98528 W: 18757 L: 18759 D: 61012

LTC:
LLR: 5.30 (-2.94,2.94) [-3.00,1.00]
Total: 204194 W: 31698 L: 31734 D: 140762

Bench: 7620871

Resolves #396
pull/396/merge
Alain SAVARD 2015-08-17 19:30:17 +01:00 committed by Joona Kiiski
parent 600234f2e2
commit 69a1a808c8
1 changed files with 1 additions and 6 deletions
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7
src/evaluate.cpp
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@ -167,7 +167,6 @@ namespace {
const Score Unstoppable = S( 0, 20);
const Score Hanging = S(31, 26);
const Score PawnAttackThreat = S(20, 20);
const Score PawnSafePush = S( 5, 5);
// Penalty for a bishop on a1/h1 (a8/h8 for black) which is trapped by
// a friendly pawn on b2/g2 (b7/g7 for black). This can obviously only
@ -527,7 +526,7 @@ namespace {
score += more_than_one(b) ? KingOnMany : KingOnOne;
}
// Add a small bonus for safe pawn pushes
// Bonus if some pawns can safely push and attack an enemy piece
b = pos.pieces(Us, PAWN) & ~TRank7BB;
b = shift_bb<Up>(b | (shift_bb<Up>(b & TRank2BB) & ~pos.pieces()));
@ -535,10 +534,6 @@ namespace {
& ~ei.attackedBy[Them][PAWN]
& (ei.attackedBy[Us][ALL_PIECES] | ~ei.attackedBy[Them][ALL_PIECES]);
if (b)
score += popcount<Full>(b) * PawnSafePush;
// Add another bonus if the pawn push attacks an enemy piece
b = (shift_bb<Left>(b) | shift_bb<Right>(b))
& pos.pieces(Them)
& ~ei.attackedBy[Us][PAWN];