]> git.sesse.net Git - stockfish/blobdiff - src/material.cpp
Merge KBPP vs KB endgame from iPhone Glaurung
[stockfish] / src / material.cpp
index 9818fdce54c904b3378537b2b0f114caf221a597..442dab56089729aaa72c4cdfcf9a76883253d163 100644 (file)
@@ -23,6 +23,9 @@
 ////
 
 #include <cassert>
+#include <cstring>
+#include <sstream>
+#include <map>
 
 #include "material.h"
 
 
 namespace {
 
-  const Value BishopPairMidgameBonus = Value(100);
-  const Value BishopPairEndgameBonus = Value(100);
-
-  Key KPKMaterialKey, KKPMaterialKey;
-  Key KBNKMaterialKey, KKBNMaterialKey;
-  Key KRKPMaterialKey, KPKRMaterialKey;
-  Key KRKBMaterialKey, KBKRMaterialKey;
-  Key KRKNMaterialKey, KNKRMaterialKey;
-  Key KQKRMaterialKey, KRKQMaterialKey;
-  Key KRPKRMaterialKey, KRKRPMaterialKey;
-  Key KRPPKRPMaterialKey, KRPKRPPMaterialKey;
+  const Value BishopPairMidgameBonus = Value(109);
+  const Value BishopPairEndgameBonus = Value(97);
+
   Key KNNKMaterialKey, KKNNMaterialKey;
-  Key KBPKBMaterialKey, KBKBPMaterialKey;
-  Key KBPKNMaterialKey, KNKBPMaterialKey;
-  Key KNPKMaterialKey, KKNPMaterialKey;
-  Key KPKPMaterialKey;
 
 }
 
+////
+//// Classes
+////
+
+
+/// See header for a class description. It is declared here to avoid
+/// to include <map> in the header file.
+
+class EndgameFunctions {
+
+public:
+  EndgameFunctions();
+  EndgameEvaluationFunctionBase* getEEF(Key key) const;
+  EndgameScalingFunctionBase* getESF(Key key, Color* c) const;
+
+private:
+  void add(const std::string& keyCode, EndgameEvaluationFunctionBase* f);
+  void add(const std::string& keyCode, Color c, EndgameScalingFunctionBase* f);
+  Key buildKey(const std::string& keyCode);
+
+  struct ScalingInfo
+  {
+      Color col;
+      EndgameScalingFunctionBase* fun;
+  };
+
+  std::map<Key, EndgameEvaluationFunctionBase*> EEFmap;
+  std::map<Key, ScalingInfo> ESFmap;
+};
+
 
 ////
 //// Functions
 ////
 
-/// MaterialInfo::init() is called during program initialization.  It
-/// precomputes material hash keys for a few basic endgames, in order
-/// to make it easy to recognize such endgames when they occur.
-
-void MaterialInfo::init() {
-  KPKMaterialKey = Position::zobMaterial[WHITE][PAWN][1];
-  KKPMaterialKey = Position::zobMaterial[BLACK][PAWN][1];
-  KBNKMaterialKey =
-    Position::zobMaterial[WHITE][BISHOP][1] ^
-    Position::zobMaterial[WHITE][KNIGHT][1];
-  KKBNMaterialKey =
-    Position::zobMaterial[BLACK][BISHOP][1] ^
-    Position::zobMaterial[BLACK][KNIGHT][1];
-  KRKPMaterialKey =
-    Position::zobMaterial[WHITE][ROOK][1] ^
-    Position::zobMaterial[BLACK][PAWN][1];
-  KPKRMaterialKey =
-    Position::zobMaterial[WHITE][PAWN][1] ^
-    Position::zobMaterial[BLACK][ROOK][1];
-  KRKBMaterialKey =
-    Position::zobMaterial[WHITE][ROOK][1] ^
-    Position::zobMaterial[BLACK][BISHOP][1];
-  KBKRMaterialKey =
-    Position::zobMaterial[WHITE][BISHOP][1] ^
-    Position::zobMaterial[BLACK][ROOK][1];
-  KRKNMaterialKey =
-    Position::zobMaterial[WHITE][ROOK][1] ^
-    Position::zobMaterial[BLACK][KNIGHT][1];
-  KNKRMaterialKey =
-    Position::zobMaterial[WHITE][KNIGHT][1] ^
-    Position::zobMaterial[BLACK][ROOK][1];
-  KQKRMaterialKey =
-    Position::zobMaterial[WHITE][QUEEN][1] ^
-    Position::zobMaterial[BLACK][ROOK][1];
-  KRKQMaterialKey =
-    Position::zobMaterial[WHITE][ROOK][1] ^
-    Position::zobMaterial[BLACK][QUEEN][1];
-  KRPKRMaterialKey =
-    Position::zobMaterial[WHITE][ROOK][1] ^
-    Position::zobMaterial[WHITE][PAWN][1] ^
-    Position::zobMaterial[BLACK][ROOK][1];
-  KRKRPMaterialKey =
-    Position::zobMaterial[WHITE][ROOK][1] ^
-    Position::zobMaterial[BLACK][ROOK][1] ^
-    Position::zobMaterial[BLACK][PAWN][1];
-  KRPPKRPMaterialKey =
-    Position::zobMaterial[WHITE][ROOK][1] ^
-    Position::zobMaterial[WHITE][PAWN][1] ^
-    Position::zobMaterial[WHITE][PAWN][2] ^
-    Position::zobMaterial[BLACK][ROOK][1] ^
-    Position::zobMaterial[BLACK][PAWN][1];
-  KRPKRPPMaterialKey =
-    Position::zobMaterial[WHITE][ROOK][1] ^
-    Position::zobMaterial[WHITE][PAWN][1] ^
-    Position::zobMaterial[BLACK][ROOK][1] ^
-    Position::zobMaterial[BLACK][PAWN][1] ^
-    Position::zobMaterial[BLACK][PAWN][2];
-  KNNKMaterialKey =
-    Position::zobMaterial[WHITE][KNIGHT][1] ^
-    Position::zobMaterial[WHITE][KNIGHT][2];
-  KKNNMaterialKey =
-    Position::zobMaterial[BLACK][KNIGHT][1] ^
-    Position::zobMaterial[BLACK][KNIGHT][2];
-  KBPKBMaterialKey =
-    Position::zobMaterial[WHITE][BISHOP][1] ^
-    Position::zobMaterial[WHITE][PAWN][1] ^
-    Position::zobMaterial[BLACK][BISHOP][1];
-  KBKBPMaterialKey =
-    Position::zobMaterial[WHITE][BISHOP][1] ^
-    Position::zobMaterial[BLACK][BISHOP][1] ^
-    Position::zobMaterial[BLACK][PAWN][1];
-  KBPKNMaterialKey =
-    Position::zobMaterial[WHITE][BISHOP][1] ^
-    Position::zobMaterial[WHITE][PAWN][1] ^
-    Position::zobMaterial[BLACK][KNIGHT][1];
-  KNKBPMaterialKey =
-    Position::zobMaterial[WHITE][KNIGHT][1] ^
-    Position::zobMaterial[BLACK][BISHOP][1] ^
-    Position::zobMaterial[BLACK][PAWN][1];
-  KNPKMaterialKey =
-    Position::zobMaterial[WHITE][KNIGHT][1] ^
-    Position::zobMaterial[WHITE][PAWN][1];
-  KKNPMaterialKey =
-    Position::zobMaterial[BLACK][KNIGHT][1] ^
-    Position::zobMaterial[BLACK][PAWN][1];
-  KPKPMaterialKey =
-    Position::zobMaterial[WHITE][PAWN][1] ^
-    Position::zobMaterial[BLACK][PAWN][1];
-}
 
+/// Constructor for the MaterialInfoTable class
 
-/// Constructor for the MaterialInfoTable class.
+MaterialInfoTable::MaterialInfoTable(unsigned int numOfEntries) {
 
-MaterialInfoTable::MaterialInfoTable(unsigned numOfEntries) {
   size = numOfEntries;
   entries = new MaterialInfo[size];
-  if(entries == NULL) {
-    std::cerr << "Failed to allocate " << (numOfEntries * sizeof(MaterialInfo))
-              << " bytes for material hash table." << std::endl;
-    exit(EXIT_FAILURE);
+  funcs = new EndgameFunctions();
+  if (!entries || !funcs)
+  {
+      std::cerr << "Failed to allocate " << (numOfEntries * sizeof(MaterialInfo))
+                << " bytes for material hash table." << std::endl;
+      exit(EXIT_FAILURE);
   }
-  this->clear();
+  clear();
 }
 
 
-/// Destructor for the MaterialInfoTable class.
+/// Destructor for the MaterialInfoTable class
 
 MaterialInfoTable::~MaterialInfoTable() {
+
   delete [] entries;
+  delete funcs;
 }
 
 
@@ -173,6 +109,7 @@ MaterialInfoTable::~MaterialInfoTable() {
 /// all entries to 0.
 
 void MaterialInfoTable::clear() {
+
   memset(entries, 0, size * sizeof(MaterialInfo));
 }
 
@@ -183,205 +120,174 @@ void MaterialInfoTable::clear() {
 /// is stored there, so we don't have to recompute everything when the
 /// same material configuration occurs again.
 
-MaterialInfo *MaterialInfoTable::get_material_info(const Position &pos) {
+MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) {
+
   Key key = pos.get_material_key();
   int index = key & (size - 1);
-  MaterialInfo *mi = entries + index;
+  MaterialInfomi = entries + index;
 
   // If mi->key matches the position's material hash key, it means that we
   // have analysed this material configuration before, and we can simply
-  // return the information we found the last time instead of recomputing it:
-  if(mi->key == key)
-    return mi;
+  // return the information we found the last time instead of recomputing it.
+  if (mi->key == key)
+      return mi;
 
-  // Clear the MaterialInfo object, and set its key:
+  // Clear the MaterialInfo object, and set its key
   mi->clear();
   mi->key = key;
 
-  // A special case before looking for a specialized evaluation function:
-  // KNN vs K is a draw:
-  if(key == KNNKMaterialKey || key == KKNNMaterialKey) {
-    mi->factor[WHITE] = mi->factor[BLACK] = 0;
-    return mi;
+  // A special case before looking for a specialized evaluation function
+  // KNN vs K is a draw.
+  if (key == KNNKMaterialKey || key == KKNNMaterialKey)
+  {
+      mi->factor[WHITE] = mi->factor[BLACK] = 0;
+      return mi;
   }
 
   // Let's look if we have a specialized evaluation function for this
-  // particular material configuration:
-  if(key == KPKMaterialKey) {
-    mi->evaluationFunction = &EvaluateKPK;
-    return mi;
-  }
-  else if(key == KKPMaterialKey) {
-    mi->evaluationFunction = &EvaluateKKP;
-    return mi;
-  }
-  else if(key == KBNKMaterialKey) {
-    mi->evaluationFunction = &EvaluateKBNK;
-    return mi;
-  }
-  else if(key == KKBNMaterialKey) {
-    mi->evaluationFunction = &EvaluateKKBN;
-    return mi;
+  // particular material configuration. First we look for a fixed
+  // configuration one, then a generic one if previous search failed.
+  if ((mi->evaluationFunction = funcs->getEEF(key)) != NULL)
+      return mi;
+
+  else if (   pos.non_pawn_material(BLACK) == Value(0)
+           && pos.piece_count(BLACK, PAWN) == 0
+           && pos.non_pawn_material(WHITE) >= RookValueEndgame)
+  {
+      mi->evaluationFunction = &EvaluateKXK;
+      return mi;
   }
-  else if(key == KRKPMaterialKey) {
-    mi->evaluationFunction = &EvaluateKRKP;
-    return mi;
+  else if (   pos.non_pawn_material(WHITE) == Value(0)
+           && pos.piece_count(WHITE, PAWN) == 0
+           && pos.non_pawn_material(BLACK) >= RookValueEndgame)
+  {
+      mi->evaluationFunction = &EvaluateKKX;
+      return mi;
   }
-  else if(key == KPKRMaterialKey) {
-    mi->evaluationFunction = &EvaluateKPKR;
-    return mi;
-  }
-  else if(key == KRKBMaterialKey) {
-    mi->evaluationFunction = &EvaluateKRKB;
-    return mi;
-  }
-  else if(key == KBKRMaterialKey) {
-    mi->evaluationFunction = &EvaluateKBKR;
-    return mi;
-  }
-  else if(key == KRKNMaterialKey) {
-    mi->evaluationFunction = &EvaluateKRKN;
-    return mi;
-  }
-  else if(key == KNKRMaterialKey) {
-    mi->evaluationFunction = &EvaluateKNKR;
-    return mi;
-  }
-  else if(key == KQKRMaterialKey) {
-    mi->evaluationFunction = &EvaluateKQKR;
-    return mi;
-  }
-  else if(key == KRKQMaterialKey) {
-    mi->evaluationFunction = &EvaluateKRKQ;
-    return mi;
-  }
-  else if(pos.non_pawn_material(BLACK) == Value(0) &&
-          pos.piece_count(BLACK, PAWN) == 0 &&
-          pos.non_pawn_material(WHITE) >= RookValueEndgame) {
-    mi->evaluationFunction = &EvaluateKXK;
-    return mi;
-  }
-  else if(pos.non_pawn_material(WHITE) == Value(0) &&
-          pos.piece_count(WHITE, PAWN) == 0 &&
-          pos.non_pawn_material(BLACK) >= RookValueEndgame) {
-    mi->evaluationFunction = &EvaluateKKX;
-    return mi;
+  else if (   pos.pawns() == EmptyBoardBB
+           && pos.rooks() == EmptyBoardBB
+           && pos.queens() == EmptyBoardBB)
+  {
+      // Minor piece endgame with at least one minor piece per side,
+      // and no pawns.
+      assert(pos.knights(WHITE) | pos.bishops(WHITE));
+      assert(pos.knights(BLACK) | pos.bishops(BLACK));
+
+      if (   pos.piece_count(WHITE, BISHOP) + pos.piece_count(WHITE, KNIGHT) <= 2
+          && pos.piece_count(BLACK, BISHOP) + pos.piece_count(BLACK, KNIGHT) <= 2)
+      {
+          mi->evaluationFunction = &EvaluateKmmKm;
+          return mi;
+      }
   }
 
   // OK, we didn't find any special evaluation function for the current
-  // material configuration.  Is there a suitable scaling function?
+  // material configuration. Is there a suitable scaling function?
   //
   // The code below is rather messy, and it could easily get worse later,
   // if we decide to add more special cases.  We face problems when there
   // are several conflicting applicable scaling functions and we need to
   // decide which one to use.
+  Color c;
+  EndgameScalingFunctionBase* sf;
 
-  if(key == KRPKRMaterialKey) {
-    mi->scalingFunction[WHITE] = &ScaleKRPKR;
-    return mi;
-  }
-  if(key == KRKRPMaterialKey) {
-    mi->scalingFunction[BLACK] = &ScaleKRKRP;
-    return mi;
-  }
-  if(key == KRPPKRPMaterialKey) {
-    mi->scalingFunction[WHITE] = &ScaleKRPPKRP;
-    return mi;
-  }
-  else if(key == KRPKRPPMaterialKey) {
-    mi->scalingFunction[BLACK] = &ScaleKRPKRPP;
-    return mi;
-  }
-  if(key == KBPKBMaterialKey) {
-    mi->scalingFunction[WHITE] = &ScaleKBPKB;
-    return mi;
-  }
-  if(key == KBKBPMaterialKey) {
-    mi->scalingFunction[BLACK] = &ScaleKBKBP;
-    return mi;
-  }
-  if(key == KBPKNMaterialKey) {
-    mi->scalingFunction[WHITE] = &ScaleKBPKN;
-    return mi;
-  }
-  if(key == KNKBPMaterialKey) {
-    mi->scalingFunction[BLACK] = &ScaleKNKBP;
-    return mi;
-  }
-  if(key == KNPKMaterialKey) {
-    mi->scalingFunction[WHITE] = &ScaleKNPK;
-    return mi;
+  if ((sf = funcs->getESF(key, &c)) != NULL)
+  {
+      mi->scalingFunction[c] = sf;
+      return mi;
   }
-  if(key == KKNPMaterialKey) {
-    mi->scalingFunction[BLACK] = &ScaleKKNP;
-    return mi;
+
+  if (   pos.non_pawn_material(WHITE) == BishopValueMidgame
+      && pos.piece_count(WHITE, BISHOP) == 1
+      && pos.piece_count(WHITE, PAWN) >= 1)
+      mi->scalingFunction[WHITE] = &ScaleKBPK;
+
+  if (   pos.non_pawn_material(BLACK) == BishopValueMidgame
+      && pos.piece_count(BLACK, BISHOP) == 1
+      && pos.piece_count(BLACK, PAWN) >= 1)
+      mi->scalingFunction[BLACK] = &ScaleKKBP;
+
+  if (   pos.piece_count(WHITE, PAWN) == 0
+      && pos.non_pawn_material(WHITE) == QueenValueMidgame
+      && pos.piece_count(WHITE, QUEEN) == 1
+      && pos.piece_count(BLACK, ROOK) == 1
+      && pos.piece_count(BLACK, PAWN) >= 1)
+      mi->scalingFunction[WHITE] = &ScaleKQKRP;
+
+  else if (   pos.piece_count(BLACK, PAWN) == 0
+           && pos.non_pawn_material(BLACK) == QueenValueMidgame
+           && pos.piece_count(BLACK, QUEEN) == 1
+           && pos.piece_count(WHITE, ROOK) == 1
+           && pos.piece_count(WHITE, PAWN) >= 1)
+      mi->scalingFunction[BLACK] = &ScaleKRPKQ;
+
+  if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) == Value(0))
+  {
+      if (pos.piece_count(BLACK, PAWN) == 0)
+      {
+          assert(pos.piece_count(WHITE, PAWN) >= 2);
+          mi->scalingFunction[WHITE] = &ScaleKPsK;
+      }
+      else if (pos.piece_count(WHITE, PAWN) == 0)
+      {
+          assert(pos.piece_count(BLACK, PAWN) >= 2);
+          mi->scalingFunction[BLACK] = &ScaleKKPs;
+      }
+      else if (pos.piece_count(WHITE, PAWN) == 1 && pos.piece_count(BLACK, PAWN) == 1)
+      {
+          mi->scalingFunction[WHITE] = &ScaleKPKPw;
+          mi->scalingFunction[BLACK] = &ScaleKPKPb;
+      }
   }
 
-  if(pos.non_pawn_material(WHITE) == BishopValueMidgame &&
-     pos.piece_count(WHITE, BISHOP) == 1 && pos.piece_count(WHITE, PAWN) >= 1)
-    mi->scalingFunction[WHITE] = &ScaleKBPK;
-  if(pos.non_pawn_material(BLACK) == BishopValueMidgame &&
-     pos.piece_count(BLACK, BISHOP) == 1 && pos.piece_count(BLACK, PAWN) >= 1)
-    mi->scalingFunction[BLACK] = &ScaleKKBP;
-
-  if(pos.piece_count(WHITE, PAWN) == 0 &&
-     pos.non_pawn_material(WHITE) == QueenValueMidgame &&
-     pos.piece_count(WHITE, QUEEN) == 1 &&
-     pos.piece_count(BLACK, ROOK) == 1 && pos.piece_count(BLACK, PAWN) >= 1)
-    mi->scalingFunction[WHITE] = &ScaleKQKRP;
-  else if(pos.piece_count(BLACK, PAWN) == 0 &&
-          pos.non_pawn_material(BLACK) == QueenValueMidgame &&
-          pos.piece_count(BLACK, QUEEN) == 1 &&
-          pos.piece_count(WHITE, ROOK) == 1 && pos.piece_count(WHITE, PAWN) >= 1)
-    mi->scalingFunction[BLACK] = &ScaleKRPKQ;
-
-  if(pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) == Value(0)) {
-    if(pos.piece_count(BLACK, PAWN) == 0) {
-      assert(pos.piece_count(WHITE, PAWN) >= 2);
-      mi->scalingFunction[WHITE] = &ScaleKPsK;
-    }
-    else if(pos.piece_count(WHITE, PAWN) == 0) {
-      assert(pos.piece_count(BLACK, PAWN) >= 2);
-      mi->scalingFunction[BLACK] = &ScaleKKPs;
-    }
-    else if(pos.piece_count(WHITE, PAWN) == 1 && pos.piece_count(BLACK, PAWN) == 1) {
-      mi->scalingFunction[WHITE] = &ScaleKPKPw;
-      mi->scalingFunction[BLACK] = &ScaleKPKPb;
-    }
+  // Compute the space weight
+  if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) >=
+      2*QueenValueMidgame + 4*RookValueMidgame + 2*KnightValueMidgame)
+  {
+      int minorPieceCount =  pos.piece_count(WHITE, KNIGHT)
+                           + pos.piece_count(BLACK, KNIGHT)
+                           + pos.piece_count(WHITE, BISHOP)
+                           + pos.piece_count(BLACK, BISHOP);
+
+      mi->spaceWeight = minorPieceCount * minorPieceCount;
   }
 
-  // Evaluate the material balance.
+  // Evaluate the material balance
 
-  Color c;
   int sign;
-  Value egValue = Value(0), mgValue = Value(0);
-
-  for(c = WHITE, sign = 1; c <= BLACK; c++, sign = -sign) {
-
-    // No pawns makes it difficult to win, even with a material advantage:
-    if(pos.piece_count(c, PAWN) == 0 &&
-       pos.non_pawn_material(c) - pos.non_pawn_material(opposite_color(c))
-       <= BishopValueMidgame) {
-      if(pos.non_pawn_material(c) == pos.non_pawn_material(opposite_color(c)))
-        mi->factor[c] = 0;
-      else if(pos.non_pawn_material(c) < RookValueMidgame)
-        mi->factor[c] = 0;
-      else {
-        switch(pos.piece_count(c, BISHOP)) {
-        case 2:
-          mi->factor[c] = 32; break;
-        case 1:
-          mi->factor[c] = 12; break;
-        case 0:
-          mi->factor[c] = 6; break;
+  Value egValue = Value(0);
+  Value mgValue = Value(0);
+
+  for (c = WHITE, sign = 1; c <= BLACK; c++, sign = -sign)
+  {
+    // No pawns makes it difficult to win, even with a material advantage
+    if (   pos.piece_count(c, PAWN) == 0
+        && pos.non_pawn_material(c) - pos.non_pawn_material(opposite_color(c)) <= BishopValueMidgame)
+    {
+        if (   pos.non_pawn_material(c) == pos.non_pawn_material(opposite_color(c))
+            || pos.non_pawn_material(c) < RookValueMidgame)
+            mi->factor[c] = 0;
+        else
+        {
+            switch (pos.piece_count(c, BISHOP)) {
+            case 2:
+                mi->factor[c] = 32;
+                break;
+            case 1:
+                mi->factor[c] = 12;
+                break;
+            case 0:
+                mi->factor[c] = 6;
+                break;
+            }
         }
-      }
     }
 
-    // Bishop pair:
-    if(pos.piece_count(c, BISHOP) >= 2) {
-      mgValue += sign * BishopPairMidgameBonus;
-      egValue += sign * BishopPairEndgameBonus;
+    // Bishop pair
+    if (pos.piece_count(c, BISHOP) >= 2)
+    {
+        mgValue += sign * BishopPairMidgameBonus;
+        egValue += sign * BishopPairEndgameBonus;
     }
 
     // Knights are stronger when there are many pawns on the board.  The
@@ -392,16 +298,104 @@ MaterialInfo *MaterialInfoTable::get_material_info(const Position &pos) {
     egValue += sign * Value(pos.piece_count(c, KNIGHT)*(pos.piece_count(c, PAWN)-5)*16);
 
     // Redundancy of major pieces, again based on Kaufman's paper:
-    if(pos.piece_count(c, ROOK) >= 1) {
-      Value v = Value((pos.piece_count(c, ROOK) - 1) * 32 + pos.piece_count(c, QUEEN) * 16);
-      mgValue -= sign * v;
-      egValue -= sign * v;
+    if (pos.piece_count(c, ROOK) >= 1)
+    {
+        Value v = Value((pos.piece_count(c, ROOK) - 1) * 32 + pos.piece_count(c, QUEEN) * 16);
+        mgValue -= sign * v;
+        egValue -= sign * v;
     }
-
   }
-
   mi->mgValue = int16_t(mgValue);
   mi->egValue = int16_t(egValue);
-
   return mi;
 }
+
+
+/// EndgameFunctions member definitions. This class is used to store the maps
+/// of end game and scaling functions that MaterialInfoTable will query for
+/// each key. The maps are constant and are populated only at construction,
+/// but are per-thread instead of globals to avoid expensive locks.
+
+EndgameFunctions::EndgameFunctions() {
+
+  KNNKMaterialKey = buildKey("KNNK");
+  KKNNMaterialKey = buildKey("KKNN");
+
+  add("KPK",   &EvaluateKPK);
+  add("KKP",   &EvaluateKKP);
+  add("KBNK",  &EvaluateKBNK);
+  add("KKBN",  &EvaluateKKBN);
+  add("KRKP",  &EvaluateKRKP);
+  add("KPKR",  &EvaluateKPKR);
+  add("KRKB",  &EvaluateKRKB);
+  add("KBKR",  &EvaluateKBKR);
+  add("KRKN",  &EvaluateKRKN);
+  add("KNKR",  &EvaluateKNKR);
+  add("KQKR",  &EvaluateKQKR);
+  add("KRKQ",  &EvaluateKRKQ);
+  add("KBBKN", &EvaluateKBBKN);
+  add("KNKBB", &EvaluateKNKBB);
+
+  add("KNPK",    WHITE, &ScaleKNPK);
+  add("KKNP",    BLACK, &ScaleKKNP);
+  add("KRPKR",   WHITE, &ScaleKRPKR);
+  add("KRKRP",   BLACK, &ScaleKRKRP);
+  add("KBPKB",   WHITE, &ScaleKBPKB);
+  add("KBKBP",   BLACK, &ScaleKBKBP);
+  add("KBPPKB",  WHITE, &ScaleKBPPKB);
+  add("KBKBPP",  BLACK, &ScaleKBKBPP);
+  add("KBPKN",   WHITE, &ScaleKBPKN);
+  add("KNKBP",   BLACK, &ScaleKNKBP);
+  add("KRPPKRP", WHITE, &ScaleKRPPKRP);
+  add("KRPKRPP", BLACK, &ScaleKRPKRPP);
+  add("KRPPKRP", WHITE, &ScaleKRPPKRP);
+  add("KRPKRPP", BLACK, &ScaleKRPKRPP);
+}
+
+Key EndgameFunctions::buildKey(const std::string& keyCode) {
+
+    assert(keyCode.length() > 0 && keyCode[0] == 'K');
+    assert(keyCode.length() < 8);
+
+    std::stringstream s;
+    bool upcase = false;
+
+    // Build up a fen substring with the given pieces, note
+    // that the fen string could be of an illegal position.
+    for (size_t i = 0; i < keyCode.length(); i++)
+    {
+        if (keyCode[i] == 'K')
+            upcase = !upcase;
+
+        s << char(upcase? toupper(keyCode[i]) : tolower(keyCode[i]));
+    }
+    s << 8 - keyCode.length() << "/8/8/8/8/8/8/8 w -";
+    return Position(s.str()).get_material_key();
+}
+
+void EndgameFunctions::add(const std::string& keyCode, EndgameEvaluationFunctionBase* f) {
+
+  EEFmap.insert(std::pair<Key, EndgameEvaluationFunctionBase*>(buildKey(keyCode), f));
+}
+
+void EndgameFunctions::add(const std::string& keyCode, Color c, EndgameScalingFunctionBase* f) {
+
+  ScalingInfo s = {c, f};
+  ESFmap.insert(std::pair<Key, ScalingInfo>(buildKey(keyCode), s));
+}
+
+EndgameEvaluationFunctionBase* EndgameFunctions::getEEF(Key key) const {
+
+  std::map<Key, EndgameEvaluationFunctionBase*>::const_iterator it(EEFmap.find(key));
+  return (it != EEFmap.end() ? it->second : NULL);
+}
+
+EndgameScalingFunctionBase* EndgameFunctions::getESF(Key key, Color* c) const {
+
+  std::map<Key, ScalingInfo>::const_iterator it(ESFmap.find(key));
+  if (it == ESFmap.end())
+      return NULL;
+
+  *c = it->second.col;
+  return it->second.fun;
+}