Tweak initiative and Pawn PSQT (#1957)

Small changes in initiative(). For Pawn PSQT, endgame values for d6-e6 and d7-e7 are now symmetric. The MG value of d2 is now smaller than e2 (d2=13, e2=21 now compared to d2=19, e2=16 before). The MG values of h5-h6-h7 also increased so this might encourage stockfish for more h-pawn pushes.

STC
LLR: -2.96 (-2.94,2.94) [0.00,4.00]
Total: 81141 W: 17933 L: 17777 D: 45431
http://tests.stockfishchess.org/tests/view/5c4017350ebc5902bb5cf237

LTC
LLR: 2.96 (-2.94,2.94) [0.00,4.00]
Total: 83078 W: 13883 L: 13466 D: 55729
http://tests.stockfishchess.org/tests/view/5c40763f0ebc5902bb5cff09

Bench: 3266398

src/evaluate.cpp

@@ -743,12 +743,12 @@ namespace {
                             && (pos.pieces(PAWN) & KingSide);
 
     // Compute the initiative bonus for the attacking side
-    int complexity =   8 * pe->pawn_asymmetry()
-                    + 12 * pos.count<PAWN>()
-                    + 12 * outflanking
-                    + 16 * pawnsOnBothFlanks
-                    + 48 * !pos.non_pawn_material()
-                    -118 ;
+    int complexity =   9 * pe->pawn_asymmetry()
+                    + 11 * pos.count<PAWN>()
+                    +  9 * outflanking
+                    + 18 * pawnsOnBothFlanks
+                    + 49 * !pos.non_pawn_material()
+                    -121 ;
 
     // Now apply the bonus: note that we find the attacking side by extracting
     // the sign of the endgame value, and that we carefully cap the bonus so

src/psqt.cpp

@@ -93,12 +93,12 @@ constexpr Score Bonus[][RANK_NB][int(FILE_NB) / 2] = {
 constexpr Score PBonus[RANK_NB][FILE_NB] =
   { // Pawn (asymmetric distribution)
    { },
-   { S(  0,-11), S( -3,-4), S(13, -1), S( 19, -4), S(16, 17), S(13,  7), S(  4,  4), S( -4,-13) },
-   { S(-16, -8), S(-12,-6), S(20, -3), S( 21,  0), S(25,-11), S(29,  3), S(  0,  0), S(-27, -1) },
-   { S(-11,  3), S(-17, 6), S(11,-10), S( 21,  1), S(32, -6), S(19,-11), S( -5,  0), S(-14, -2) },
-   { S(  4, 13), S(  6, 7), S(-8,  3), S(  3, -5), S( 8,-15), S(-2, -1), S(-19,  9), S( -5, 13) },
-   { S( -5, 25), S(-19,20), S( 7, 16), S(  8, 12), S(-7, 21), S(-2,  3), S(-10, -4), S(-16, 15) },
-   { S(-10,  6), S(  9,-5), S(-7, 16), S(-12, 27), S(-7, 15), S(-8, 11), S( 16, -7), S( -8,  4) }
+   { S(  0,-10), S( -5,-3), S( 10,  7), S( 13, -1), S( 21,  7), S( 17,  6), S(  6,  1), S( -3,-20) },
+   { S(-11, -6), S(-10,-6), S( 15, -1), S( 22, -1), S( 26, -1), S( 28,  2), S(  4, -2), S(-24, -5) },
+   { S( -9,  4), S(-18,-5), S(  8, -4), S( 22, -5), S( 33, -6), S( 25,-13), S( -4, -3), S(-16, -7) },
+   { S(  6, 18), S( -3, 2), S(-10,  2), S(  1, -9), S( 12,-13), S(  6, -8), S(-12, 11), S(  1,  9) },
+   { S( -6, 25), S( -8,17), S(  5, 19), S( 11, 29), S(-14, 29), S(  0,  8), S(-12,  4), S(-14, 12) },
+   { S(-10, -1), S(  6,-6), S( -5, 18), S(-11, 22), S( -2, 22), S(-14, 17), S( 12,  2), S( -1,  9) }
   };
 
 #undef S