Use an affine formula to mix stats and eval

[stockfish] / src / psqt.cpp

diff --git a/src/psqt.cpp b/src/psqt.cpp
index 0d16b1c382851fa0b7da05692e603917c6b470d9..f29b9c400f69f954cb73393f6f5eeacbbe87a1b7 100644 (file)
--- a/src/psqt.cpp
+++ b/src/psqt.cpp
@@ -2,7 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
-  Copyright (C) 2015-2017 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+  Copyright (C) 2015-2018 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -35,7 +35,7 @@ namespace PSQT {
 // type on a given square a (middlegame, endgame) score pair is assigned. Table
 // is defined for files A..D and white side: it is symmetric for black side and
 // second half of the files.
-const Score Bonus[][RANK_NB][int(FILE_NB) / 2] = {
+constexpr Score Bonus[][RANK_NB][int(FILE_NB) / 2] = {
   { },
   { // Pawn
    { S(  0, 0), S(  0, 0), S(  0, 0), S( 0, 0) },
@@ -87,14 +87,14 @@ const Score Bonus[][RANK_NB][int(FILE_NB) / 2] = {
    { S(-1,-74), S(-4,-55), S(-1,-43), S( 0,-30) }
   },
   { // King
-   { S(267,  0), S(320, 48), S(270, 75), S(195, 84) },
-   { S(264, 43), S(304, 92), S(238,143), S(180,132) },
-   { S(200, 83), S(245,138), S(176,167), S(110,165) },
-   { S(177,106), S(185,169), S(148,169), S(110,179) },
-   { S(149,108), S(177,163), S(115,200), S( 66,203) },
-   { S(118, 95), S(159,155), S( 84,176), S( 41,174) },
-   { S( 87, 50), S(128, 99), S( 63,122), S( 20,139) },
-   { S( 63,  9), S( 88, 55), S( 47, 80), S(  0, 90) }
+   { S(272,  0), S(325, 41), S(273, 80), S(190, 93) },
+   { S(277, 57), S(305, 98), S(241,138), S(183,131) },
+   { S(198, 86), S(253,138), S(168,165), S(120,173) },
+   { S(169,103), S(191,152), S(136,168), S(108,169) },
+   { S(145, 98), S(176,166), S(112,197), S(69, 194) },
+   { S(122, 87), S(159,164), S(85, 174), S(36, 189) },
+   { S(87,  40), S(120, 99), S(64, 128), S(25, 141) },
+   { S(64,   5), S(87,  60), S(49,  75), S(0,   75) }
   }
 };
 
@@ -112,12 +112,12 @@ void init() {
       PieceValue[MG][~pc] = PieceValue[MG][pc];
       PieceValue[EG][~pc] = PieceValue[EG][pc];
 
-      Score v = make_score(PieceValue[MG][pc], PieceValue[EG][pc]);
+      Score score = make_score(PieceValue[MG][pc], PieceValue[EG][pc]);
 
       for (Square s = SQ_A1; s <= SQ_H8; ++s)
       {
-          File f = std::min(file_of(s), FILE_H - file_of(s));
-          psq[ pc][ s] = v + Bonus[pc][rank_of(s)][f];
+          File f = std::min(file_of(s), ~file_of(s));
+          psq[ pc][ s] = score + Bonus[pc][rank_of(s)][f];
           psq[~pc][~s] = -psq[pc][s];
       }
   }