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Double pawn simplification 

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
pull/660/head^2
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
View File

@ -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)];

13
src/psqt.cpp
View File

@ -38,13 +38,12 @@ const Score Bonus[][RANK_NB][int(FILE_NB) / 2] = {
{ },
{ // Pawn
{ S( 0, 0), S( 0, 0), S( 0, 0), S( 0, 0) },
{ S(-19, 5), S( 1,-4), S( 7, 8), S( 3,-2) },
{ S(-26,-6), S( -7,-5), S( 19, 5), S(24, 4) },
{ S(-25, 1), S(-14, 3), S( 20,-8), S(35,-3) },
{ S(-14, 6), S( 0, 9), S( 3, 7), S(21,-6) },
{ S(-14, 6), S(-13,-5), S( -6, 2), S(-2, 4) },
{ S(-12, 1), S( 15,-9), S( -8, 1), S(-4,18) },
{ S( 0, 0), S( 0, 0), S( 0, 0), S( 0, 0) }
{ S(-16, 7), S( 1,-4), S( 7, 8), S( 3,-2) },
{ S(-23,-4), S( -7,-5), S( 19, 5), S(24, 4) },
{ S(-22, 3), S(-14, 3), S( 20,-8), S(35,-3) },
{ S(-11, 8), S( 0, 9), S( 3, 7), S(21,-6) },
{ S(-11, 8), S(-13,-5), S( -6, 2), S(-2, 4) },
{ S( -9, 3), S( 15,-9), S( -8, 1), S(-4,18) }
},
{ // Knight
{ S(-143, -97), S(-96,-82), S(-80,-46), S(-73,-14) },