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Double pawn simplification

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Try doubled pawn simplification, with psq
table compensation.

STC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 36094 W: 6558 L: 6463 D: 23073

LTC:
LLR: 2.94 (-2.94,2.94) [-3.00,1.00]
Total: 102352 W: 13417 L: 13404 D: 75531

Bench: 8716243
This commit is contained in:
Stéphane Nicolet
2016-05-11 06:48:51 +02:00
committed by Marco Costalba
parent 969982406c
commit 16c603ce9b
2 changed files with 10 additions and 13 deletions
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10
src/pawns.cpp
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@@ -44,10 +44,8 @@ namespace {
// Connected pawn bonus by opposed, phalanx, twice supported and rank
Score Connected[2][2][2][RANK_NB];
// Doubled pawn penalty by file
const Score Doubled[FILE_NB] = {
S(11, 34), S(17, 38), S(19, 38), S(19, 38),
S(19, 38), S(19, 38), S(17, 38), S(11, 34) };
// Doubled pawn penalty
const Score Doubled = S(18,38);
// Lever bonus by rank
const Score Lever[RANK_NB] = {
@@ -145,7 +143,7 @@ namespace {
// either there is a stopper in the way on this rank, or there is a
// stopper on adjacent file which controls the way to that rank.
backward = (b | shift_bb<Up>(b & adjacent_files_bb(f))) & stoppers;
assert(!backward || !(pawn_attack_span(Them, s + Up) & neighbours));
}
@@ -169,7 +167,7 @@ namespace {
score += Connected[opposed][!!phalanx][more_than_one(supported)][relative_rank(Us, s)];
if (doubled)
score -= Doubled[f] / distance<Rank>(s, frontmost_sq(Us, doubled));
score -= Doubled / distance<Rank>(s, frontmost_sq(Us, doubled));
if (lever)
score += Lever[relative_rank(Us, s)];