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

diff --git a/src/pawns.cpp b/src/pawns.cpp
index c5c42ff14a593bc08caf2d914c0cdda6846ce0b0..74b3fd5e5d9c473f32ead6551ba5163931c52562 100644 (file)
--- a/src/pawns.cpp
+++ b/src/pawns.cpp
@@ -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)];

diff --git a/src/psqt.cpp b/src/psqt.cpp
index 76e4e7decdf439838f2569cafe4b5ac1836dd676..60180adfb860b4d7ef43f903cf825615ffc9c3ef 100644 (file)
--- a/src/psqt.cpp
+++ b/src/psqt.cpp
@@ -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) },