Merged two new endgames from Glaurung 2.2

[stockfish] / src / endgame.cpp

diff --git a/src/endgame.cpp b/src/endgame.cpp
index ee8b9179c2d79ecfab93a197b329cd353041604d..4d93811e7c5d15fa2fc47d1ab16e97377a448d29 100644 (file)
--- a/src/endgame.cpp
+++ b/src/endgame.cpp
@@ -1,13 +1,14 @@
 /*
-  Glaurung, a UCI chess playing engine.
-  Copyright (C) 2004-2008 Tord Romstad
+  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+  Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
+  Copyright (C) 2008 Marco Costalba
 
-  Glaurung is free software: you can redistribute it and/or modify
+  Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.
   
-  Glaurung is distributed in the hope that it will be useful,
+  Stockfish is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
@@ -61,6 +62,13 @@ KRKNEvaluationFunction EvaluateKNKR = KRKNEvaluationFunction(BLACK);
 KQKREvaluationFunction EvaluateKQKR = KQKREvaluationFunction(WHITE);
 KQKREvaluationFunction EvaluateKRKQ = KQKREvaluationFunction(BLACK);
 
+// KBB vs KN:
+KBBKNEvaluationFunction EvaluateKBBKN = KBBKNEvaluationFunction(WHITE);
+KBBKNEvaluationFunction EvaluateKNKBB = KBBKNEvaluationFunction(BLACK);
+
+// K and two minors vs K and one or two minors:
+KmmKmEvaluationFunction EvaluateKmmKm = KmmKmEvaluationFunction(WHITE);
+
 
 /// Scaling functions
 
@@ -186,6 +194,8 @@ KRKPEvaluationFunction::KRKPEvaluationFunction(Color c) : EndgameEvaluationFunct
 KRKBEvaluationFunction::KRKBEvaluationFunction(Color c) : EndgameEvaluationFunction(c) { }
 KRKNEvaluationFunction::KRKNEvaluationFunction(Color c) : EndgameEvaluationFunction(c) { }
 KQKREvaluationFunction::KQKREvaluationFunction(Color c) : EndgameEvaluationFunction(c) { }
+KBBKNEvaluationFunction::KBBKNEvaluationFunction(Color c) : EndgameEvaluationFunction(c) { }
+KmmKmEvaluationFunction::KmmKmEvaluationFunction(Color c) : EndgameEvaluationFunction(c) { }
 
 
 ScalingFunction::ScalingFunction(Color c) {
@@ -212,19 +222,19 @@ KPKPScalingFunction::KPKPScalingFunction(Color c) : ScalingFunction(c) { }
 Value KXKEvaluationFunction::apply(const Position &pos) {
 
   assert(pos.non_pawn_material(weakerSide) == Value(0));
-  assert(pos.pawn_count(weakerSide) == Value(0));
+  assert(pos.piece_count(weakerSide, PAWN) == Value(0));
 
   Square winnerKSq = pos.king_square(strongerSide);
   Square loserKSq = pos.king_square(weakerSide);
 
   Value result =
     pos.non_pawn_material(strongerSide) +
-    pos.pawn_count(strongerSide) * PawnValueEndgame +
+    pos.piece_count(strongerSide, PAWN) * PawnValueEndgame +
     mate_table(loserKSq) +
     distance_bonus(square_distance(winnerKSq, loserKSq));
 
-  if(pos.queen_count(strongerSide) > 0 || pos.rook_count(strongerSide) > 0 ||
-     pos.bishop_count(strongerSide) > 1)
+  if(pos.piece_count(strongerSide, QUEEN) > 0 || pos.piece_count(strongerSide, ROOK) > 0 ||
+     pos.piece_count(strongerSide, BISHOP) > 1)
     // TODO: check for two equal-colored bishops!
     result += VALUE_KNOWN_WIN;
 
@@ -238,12 +248,12 @@ Value KXKEvaluationFunction::apply(const Position &pos) {
 Value KBNKEvaluationFunction::apply(const Position &pos) {
 
   assert(pos.non_pawn_material(weakerSide) == Value(0));
-  assert(pos.pawn_count(weakerSide) == Value(0));
+  assert(pos.piece_count(weakerSide, PAWN) == Value(0));
   assert(pos.non_pawn_material(strongerSide) ==
          KnightValueMidgame + BishopValueMidgame);
-  assert(pos.bishop_count(strongerSide) == 1);
-  assert(pos.knight_count(strongerSide) == 1);
-  assert(pos.pawn_count(strongerSide) == 0);
+  assert(pos.piece_count(strongerSide, BISHOP) == 1);
+  assert(pos.piece_count(strongerSide, KNIGHT) == 1);
+  assert(pos.piece_count(strongerSide, PAWN) == 0);
 
   Square winnerKSq = pos.king_square(strongerSide);
   Square loserKSq = pos.king_square(weakerSide);
@@ -268,8 +278,8 @@ Value KPKEvaluationFunction::apply(const Position &pos) {
 
   assert(pos.non_pawn_material(strongerSide) == Value(0));
   assert(pos.non_pawn_material(weakerSide) == Value(0));
-  assert(pos.pawn_count(strongerSide) == 1);
-  assert(pos.pawn_count(weakerSide) == 0);
+  assert(pos.piece_count(strongerSide, PAWN) == 1);
+  assert(pos.piece_count(weakerSide, PAWN) == 0);
   
   Square wksq, bksq, wpsq;
   Color stm;
@@ -311,9 +321,9 @@ Value KPKEvaluationFunction::apply(const Position &pos) {
 Value KRKPEvaluationFunction::apply(const Position &pos) {
 
   assert(pos.non_pawn_material(strongerSide) == RookValueMidgame);
-  assert(pos.pawn_count(strongerSide) == 0);
+  assert(pos.piece_count(strongerSide, PAWN) == 0);
   assert(pos.non_pawn_material(weakerSide) == 0);
-  assert(pos.pawn_count(weakerSide) == 1);
+  assert(pos.piece_count(weakerSide, PAWN) == 1);
 
   Square wksq, wrsq, bksq, bpsq;
   int tempo = (pos.side_to_move() == strongerSide);
@@ -366,10 +376,10 @@ Value KRKPEvaluationFunction::apply(const Position &pos) {
 Value KRKBEvaluationFunction::apply(const Position &pos) {
 
   assert(pos.non_pawn_material(strongerSide) == RookValueMidgame);
-  assert(pos.pawn_count(strongerSide) == 0);
+  assert(pos.piece_count(strongerSide, PAWN) == 0);
   assert(pos.non_pawn_material(weakerSide) == BishopValueMidgame);
-  assert(pos.pawn_count(weakerSide) == 0);
-  assert(pos.bishop_count(weakerSide) == 1);
+  assert(pos.piece_count(weakerSide, PAWN) == 0);
+  assert(pos.piece_count(weakerSide, BISHOP) == 1);
 
   Value result = mate_table(pos.king_square(weakerSide));
   return (pos.side_to_move() == strongerSide)? result : -result;
@@ -382,10 +392,10 @@ Value KRKBEvaluationFunction::apply(const Position &pos) {
 Value KRKNEvaluationFunction::apply(const Position &pos) {
 
   assert(pos.non_pawn_material(strongerSide) == RookValueMidgame);
-  assert(pos.pawn_count(strongerSide) == 0);
+  assert(pos.piece_count(strongerSide, PAWN) == 0);
   assert(pos.non_pawn_material(weakerSide) == KnightValueMidgame);
-  assert(pos.pawn_count(weakerSide) == 0);
-  assert(pos.knight_count(weakerSide) == 1);
+  assert(pos.piece_count(weakerSide, PAWN) == 0);
+  assert(pos.piece_count(weakerSide, KNIGHT) == 1);
 
   Square defendingKSq = pos.king_square(weakerSide);
   Square nSq = pos.piece_list(weakerSide, KNIGHT, 0);
@@ -405,9 +415,9 @@ Value KRKNEvaluationFunction::apply(const Position &pos) {
 
 Value KQKREvaluationFunction::apply(const Position &pos) {
   assert(pos.non_pawn_material(strongerSide) == QueenValueMidgame);
-  assert(pos.pawn_count(strongerSide) == 0);
+  assert(pos.piece_count(strongerSide, PAWN) == 0);
   assert(pos.non_pawn_material(weakerSide) == RookValueMidgame);
-  assert(pos.pawn_count(weakerSide) == 0);
+  assert(pos.piece_count(weakerSide, PAWN) == 0);
 
   Square winnerKSq = pos.king_square(strongerSide);
   Square loserKSq = pos.king_square(weakerSide);
@@ -419,6 +429,36 @@ Value KQKREvaluationFunction::apply(const Position &pos) {
 }
 
 
+Value KBBKNEvaluationFunction::apply(const Position &pos) {
+  assert(pos.piece_count(strongerSide, BISHOP) == 2);
+  assert(pos.non_pawn_material(strongerSide) == 2*BishopValueMidgame);
+  assert(pos.piece_count(weakerSide, KNIGHT) == 1);
+  assert(pos.non_pawn_material(weakerSide) == KnightValueMidgame);
+  assert(pos.pawns() == EmptyBoardBB);
+
+  Value result = BishopValueEndgame;
+  Square wksq = pos.king_square(strongerSide);
+  Square bksq = pos.king_square(weakerSide);
+  Square nsq = pos.piece_list(weakerSide, KNIGHT, 0);
+
+  // Bonus for attacking king close to defending king
+  result += distance_bonus(square_distance(wksq, bksq));
+
+  // Bonus for driving the defending king and knight apart
+  result += Value(square_distance(bksq, nsq) * 32);
+
+  // Bonus for restricting the knight's mobility
+  result += Value((8 - count_1s_max_15(pos.piece_attacks<KNIGHT>(nsq))) * 8);
+
+  return (strongerSide == pos.side_to_move())? result : -result;
+}
+
+
+Value KmmKmEvaluationFunction::apply(const Position &pos) {
+  return Value(0);
+}
+
+
 /// KBPKScalingFunction scales endgames where the stronger side has king,
 /// bishop and one or more pawns.  It checks for draws with rook pawns and a
 /// bishop of the wrong color.  If such a draw is detected, ScaleFactor(0) is
@@ -427,8 +467,8 @@ Value KQKREvaluationFunction::apply(const Position &pos) {
 
 ScaleFactor KBPKScalingFunction::apply(const Position &pos) {
   assert(pos.non_pawn_material(strongerSide) == BishopValueMidgame);
-  assert(pos.bishop_count(strongerSide) == 1);
-  assert(pos.pawn_count(strongerSide) >= 1);
+  assert(pos.piece_count(strongerSide, BISHOP) == 1);
+  assert(pos.piece_count(strongerSide, PAWN) >= 1);
 
   // No assertions about the material of weakerSide, because we want draws to
   // be detected even when the weaker side has some pawns.
@@ -479,10 +519,10 @@ ScaleFactor KBPKScalingFunction::apply(const Position &pos) {
 
 ScaleFactor KQKRPScalingFunction::apply(const Position &pos) {
   assert(pos.non_pawn_material(strongerSide) == QueenValueMidgame);
-  assert(pos.queen_count(strongerSide) == 1);
-  assert(pos.pawn_count(strongerSide) == 0);
-  assert(pos.rook_count(weakerSide) == 1);
-  assert(pos.pawn_count(weakerSide) >= 1);
+  assert(pos.piece_count(strongerSide, QUEEN) == 1);
+  assert(pos.piece_count(strongerSide, PAWN) == 0);
+  assert(pos.piece_count(weakerSide, ROOK) == 1);
+  assert(pos.piece_count(weakerSide, PAWN) >= 1);
 
   Square kingSq = pos.king_square(weakerSide);
   if(relative_rank(weakerSide, kingSq) <= RANK_2 &&
@@ -508,9 +548,9 @@ ScaleFactor KQKRPScalingFunction::apply(const Position &pos) {
 
 ScaleFactor KRPKRScalingFunction::apply(const Position &pos) {
   assert(pos.non_pawn_material(strongerSide) == RookValueMidgame);
-  assert(pos.pawn_count(strongerSide) == 1);
+  assert(pos.piece_count(strongerSide, PAWN) == 1);
   assert(pos.non_pawn_material(weakerSide) == RookValueMidgame);
-  assert(pos.pawn_count(weakerSide) == 0);
+  assert(pos.piece_count(weakerSide, PAWN) == 0);
 
   Square wksq = pos.king_square(strongerSide);
   Square wrsq = pos.piece_list(strongerSide, ROOK, 0);
@@ -603,6 +643,16 @@ ScaleFactor KRPKRScalingFunction::apply(const Position &pos) {
                   - (8 * square_distance(wpsq, queeningSq) +
                      2 * square_distance(wksq, queeningSq)));
 
+  // If the pawn is not far advanced, and the defending king is somewhere in
+  // the pawn's path, it's probably a draw:
+  if(r <= RANK_4 && bksq > wpsq) {
+    if(square_file(bksq) == square_file(wpsq))
+      return ScaleFactor(10);
+    if(abs(square_file(bksq) - square_file(wpsq)) == 1
+       && square_distance(wksq, bksq) > 2)
+      return ScaleFactor(24 - 2 * square_distance(wksq, bksq));
+  }
+
   return SCALE_FACTOR_NONE;
 }
 
@@ -613,9 +663,9 @@ ScaleFactor KRPKRScalingFunction::apply(const Position &pos) {
 
 ScaleFactor KRPPKRPScalingFunction::apply(const Position &pos) {
   assert(pos.non_pawn_material(strongerSide) == RookValueMidgame);
-  assert(pos.pawn_count(strongerSide) == 2);
+  assert(pos.piece_count(strongerSide, PAWN) == 2);
   assert(pos.non_pawn_material(weakerSide) == RookValueMidgame);
-  assert(pos.pawn_count(weakerSide) == 1);
+  assert(pos.piece_count(weakerSide, PAWN) == 1);
 
   Square wpsq1 = pos.piece_list(strongerSide, PAWN, 0);
   Square wpsq2 = pos.piece_list(strongerSide, PAWN, 1);
@@ -651,9 +701,9 @@ ScaleFactor KRPPKRPScalingFunction::apply(const Position &pos) {
 
 ScaleFactor KPsKScalingFunction::apply(const Position &pos) {
   assert(pos.non_pawn_material(strongerSide) == Value(0));
-  assert(pos.pawn_count(strongerSide) >= 2);
+  assert(pos.piece_count(strongerSide, PAWN) >= 2);
   assert(pos.non_pawn_material(weakerSide) == Value(0));
-  assert(pos.pawn_count(weakerSide) == 0);
+  assert(pos.piece_count(weakerSide, PAWN) == 0);
 
   Bitboard pawns = pos.pawns(strongerSide);
 
@@ -694,11 +744,11 @@ ScaleFactor KPsKScalingFunction::apply(const Position &pos) {
 
 ScaleFactor KBPKBScalingFunction::apply(const Position &pos) {
   assert(pos.non_pawn_material(strongerSide) == BishopValueMidgame);
-  assert(pos.bishop_count(strongerSide) == 1);
-  assert(pos.pawn_count(strongerSide) == 1);
+  assert(pos.piece_count(strongerSide, BISHOP) == 1);
+  assert(pos.piece_count(strongerSide, PAWN) == 1);
   assert(pos.non_pawn_material(weakerSide) == BishopValueMidgame);
-  assert(pos.bishop_count(weakerSide) == 1);
-  assert(pos.pawn_count(weakerSide) == 0);
+  assert(pos.piece_count(weakerSide, BISHOP) == 1);
+  assert(pos.piece_count(weakerSide, PAWN) == 0);
 
   Square pawnSq = pos.piece_list(strongerSide, PAWN, 0);
   Square strongerBishopSq = pos.piece_list(strongerSide, BISHOP, 0);
@@ -748,11 +798,11 @@ ScaleFactor KBPKBScalingFunction::apply(const Position &pos) {
 
 ScaleFactor KBPKNScalingFunction::apply(const Position &pos) {
   assert(pos.non_pawn_material(strongerSide) == BishopValueMidgame);
-  assert(pos.bishop_count(strongerSide) == 1);
-  assert(pos.pawn_count(strongerSide) == 1);
+  assert(pos.piece_count(strongerSide, BISHOP) == 1);
+  assert(pos.piece_count(strongerSide, PAWN) == 1);
   assert(pos.non_pawn_material(weakerSide) == KnightValueMidgame);
-  assert(pos.knight_count(weakerSide) == 1);
-  assert(pos.pawn_count(weakerSide) == 0);
+  assert(pos.piece_count(weakerSide, KNIGHT) == 1);
+  assert(pos.piece_count(weakerSide, PAWN) == 0);
 
   Square pawnSq = pos.piece_list(strongerSide, PAWN, 0);
   Square strongerBishopSq = pos.piece_list(strongerSide, BISHOP, 0);
@@ -774,10 +824,10 @@ ScaleFactor KBPKNScalingFunction::apply(const Position &pos) {
 
 ScaleFactor KNPKScalingFunction::apply(const Position &pos) {
   assert(pos.non_pawn_material(strongerSide) == KnightValueMidgame);
-  assert(pos.knight_count(strongerSide) == 1);
-  assert(pos.pawn_count(strongerSide) == 1);
+  assert(pos.piece_count(strongerSide, KNIGHT) == 1);
+  assert(pos.piece_count(strongerSide, PAWN) == 1);
   assert(pos.non_pawn_material(weakerSide) == Value(0));
-  assert(pos.pawn_count(weakerSide) == 0);
+  assert(pos.piece_count(weakerSide, PAWN) == 0);
 
   Square pawnSq = pos.piece_list(strongerSide, PAWN, 0);
   Square weakerKingSq = pos.king_square(weakerSide);
@@ -804,8 +854,8 @@ ScaleFactor KNPKScalingFunction::apply(const Position &pos) {
 ScaleFactor KPKPScalingFunction::apply(const Position &pos) {
   assert(pos.non_pawn_material(strongerSide) == Value(0));
   assert(pos.non_pawn_material(weakerSide) == Value(0));
-  assert(pos.pawn_count(WHITE) == 1);
-  assert(pos.pawn_count(BLACK) == 1);
+  assert(pos.piece_count(WHITE, PAWN) == 1);
+  assert(pos.piece_count(BLACK, PAWN) == 1);
 
   Square wksq, bksq, wpsq;
   Color stm;