Move game_phase() to material.cpp

[stockfish] / src / material.cpp

diff --git a/src/material.cpp b/src/material.cpp
index ebf5adff854abc4bb6770c6547795e72c7d791c7..d67b95cae96413746d77176e1dcf9bcb31c73b98 100644 (file)
--- a/src/material.cpp
+++ b/src/material.cpp
@@ -2,6 +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
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -30,29 +31,37 @@ namespace {
 
   // Polynomial material imbalance parameters
 
-  //                      pair  pawn knight bishop rook queen
-  const int Linear[6] = { 1852, -162, -1122, -183,  249, -154 };
-
   const int QuadraticOurs[][PIECE_TYPE_NB] = {
     //            OUR PIECES
     // pair pawn knight bishop rook queen
-    {   0                               }, // Bishop pair
-    {  39,    2                         }, // Pawn
-    {  35,  271,  -4                    }, // Knight      OUR PIECES
-    {   0,  105,   4,    0              }, // Bishop
-    { -27,   -2,  46,   100,  -141      }, // Rook
-    {-177,   25, 129,   142,  -137,   0 }  // Queen
+    {1667                               }, // Bishop pair
+    {  40,    0                         }, // Pawn
+    {  32,  255,  -3                    }, // Knight      OUR PIECES
+    {   0,  104,   4,    0              }, // Bishop
+    { -26,   -2,  47,   105,  -149      }, // Rook
+    {-185,   24, 122,   137,  -134,   0 }  // Queen
   };
 
   const int QuadraticTheirs[][PIECE_TYPE_NB] = {
     //           THEIR PIECES
     // pair pawn knight bishop rook queen
     {   0                               }, // Bishop pair
-    {  37,    0                         }, // Pawn
-    {  10,   62,   0                    }, // Knight      OUR PIECES
-    {  57,   64,  39,     0             }, // Bishop
-    {  50,   40,  23,   -22,    0       }, // Rook
-    {  98,  105, -39,   141,  274,    0 }  // Queen
+    {  36,    0                         }, // Pawn
+    {   9,   63,   0                    }, // Knight      OUR PIECES
+    {  59,   65,  42,     0             }, // Bishop
+    {  46,   39,  24,   -24,    0       }, // Rook
+    { 101,  100, -37,   141,  268,    0 }  // Queen
+  };
+
+  // PawnSet[pawn count] contains a bonus/malus indexed by number of pawns
+  const int PawnSet[] = {
+    24, -32, 107, -51, 117, -9, -126, -21, 31
+  };
+
+  // QueenMinorsImbalance[opp_minor_count] is applied when only one side has a queen.
+  // It contains a bonus/malus for the side with the queen.
+  const int QueenMinorsImbalance[13] = {
+    31, -8, -15, -25, -5
   };
 
   // Endgame evaluation and scaling functions are accessed directly and not through
@@ -91,7 +100,7 @@ namespace {
 
     const Color Them = (Us == WHITE ? BLACK : WHITE);
 
-    int bonus = 0;
+    int bonus = PawnSet[pieceCount[Us][PAWN]];
 
     // Second-degree polynomial material imbalance by Tord Romstad
     for (int pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; ++pt1)
@@ -99,7 +108,7 @@ namespace {
         if (!pieceCount[Us][pt1])
             continue;
 
-        int v = Linear[pt1];
+        int v = 0;
 
         for (int pt2 = NO_PIECE_TYPE; pt2 <= pt1; ++pt2)
             v +=  QuadraticOurs[pt1][pt2] * pieceCount[Us][pt2]
@@ -108,6 +117,10 @@ namespace {
         bonus += pieceCount[Us][pt1] * v;
     }
 
+    // Special handling of Queen vs. Minors
+    if  (pieceCount[Us][QUEEN] == 1 && pieceCount[Them][QUEEN] == 0)
+         bonus += QueenMinorsImbalance[pieceCount[Them][KNIGHT] + pieceCount[Them][BISHOP]];
+
     return bonus;
   }
 
@@ -131,7 +144,13 @@ Entry* probe(const Position& pos) {
   std::memset(e, 0, sizeof(Entry));
   e->key = key;
   e->factor[WHITE] = e->factor[BLACK] = (uint8_t)SCALE_FACTOR_NORMAL;
-  e->gamePhase = pos.game_phase();
+
+  Value npm_w = pos.non_pawn_material(WHITE);
+  Value npm_b = pos.non_pawn_material(BLACK);
+  Value npm = std::max(EndgameLimit, std::min(npm_w + npm_b, MidgameLimit));
+
+  // Map total non-pawn material into [PHASE_ENDGAME, PHASE_MIDGAME]
+  e->gamePhase = Phase(((npm - EndgameLimit) * PHASE_MIDGAME) / (MidgameLimit - EndgameLimit));
 
   // Let's look if we have a specialized evaluation function for this particular
   // material configuration. Firstly we look for a fixed configuration one, then
@@ -152,7 +171,7 @@ Entry* probe(const Position& pos) {
 
   if ((sf = pos.this_thread()->endgames.probe<ScaleFactor>(key)) != nullptr)
   {
-      e->scalingFunction[sf->strong_side()] = sf; // Only strong color assigned
+      e->scalingFunction[sf->strongSide] = sf; // Only strong color assigned
       return e;
   }
 
@@ -168,9 +187,6 @@ Entry* probe(const Position& pos) {
         e->scalingFunction[c] = &ScaleKQKRPs[c];
   }
 
-  Value npm_w = pos.non_pawn_material(WHITE);
-  Value npm_b = pos.non_pawn_material(BLACK);
-
   if (npm_w + npm_b == VALUE_ZERO && pos.pieces(PAWN)) // Only pawns on the board
   {
       if (!pos.count<PAWN>(BLACK))
@@ -199,11 +215,11 @@ Entry* probe(const Position& pos) {
   // drawish scale factor for cases such as KRKBP and KmmKm (except for KBBKN).
   if (!pos.count<PAWN>(WHITE) && npm_w - npm_b <= BishopValueMg)
       e->factor[WHITE] = uint8_t(npm_w <  RookValueMg   ? SCALE_FACTOR_DRAW :
-                                 npm_b <= BishopValueMg ? 4 : 12);
+                                 npm_b <= BishopValueMg ? 4 : 14);
 
   if (!pos.count<PAWN>(BLACK) && npm_b - npm_w <= BishopValueMg)
       e->factor[BLACK] = uint8_t(npm_b <  RookValueMg   ? SCALE_FACTOR_DRAW :
-                                 npm_w <= BishopValueMg ? 4 : 12);
+                                 npm_w <= BishopValueMg ? 4 : 14);
 
   if (pos.count<PAWN>(WHITE) == 1 && npm_w - npm_b <= BishopValueMg)
       e->factor[WHITE] = (uint8_t) SCALE_FACTOR_ONEPAWN;