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Massive stronger/weaker renming

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No functional change.
This commit is contained in:
Marco Costalba 2013-10-14 19:34:12 +02:00
parent 027d85e82a
commit d9be00342c
2 changed files with 192 additions and 192 deletions
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378
src/endgame.cpp
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@ -74,8 +74,8 @@ namespace {
assert(code.length() > 0 && code.length() < 8);
assert(code[0] == 'K');
string sides[] = { code.substr(code.find('K', 1)), // Weaker
code.substr(0, code.find('K', 1)) }; // Stronger
string sides[] = { code.substr(code.find('K', 1)), // Weak
code.substr(0, code.find('K', 1)) }; // Strong
std::transform(sides[c].begin(), sides[c].end(), sides[c].begin(), tolower);
@ -136,27 +136,27 @@ void Endgames::add(const string& code) {
template<>
Value Endgame<KXK>::operator()(const Position& pos) const {
assert(verify_material(pos, weakerSide, VALUE_ZERO, 0));
assert(verify_material(pos, weakSide, VALUE_ZERO, 0));
assert(!pos.checkers()); // Eval is never called when in check
// Stalemate detection with lone king
if (pos.side_to_move() == weakerSide && !MoveList<LEGAL>(pos).size())
if (pos.side_to_move() == weakSide && !MoveList<LEGAL>(pos).size())
return VALUE_DRAW;
Square winnerKSq = pos.king_square(strongerSide);
Square loserKSq = pos.king_square(weakerSide);
Square winnerKSq = pos.king_square(strongSide);
Square loserKSq = pos.king_square(weakSide);
Value result = pos.non_pawn_material(strongerSide)
+ pos.count<PAWN>(strongerSide) * PawnValueEg
Value result = pos.non_pawn_material(strongSide)
+ pos.count<PAWN>(strongSide) * PawnValueEg
+ PushToEdges[loserKSq]
+ PushClose[square_distance(winnerKSq, loserKSq)];
if ( pos.count<QUEEN>(strongerSide)
|| pos.count<ROOK>(strongerSide)
|| pos.bishop_pair(strongerSide))
if ( pos.count<QUEEN>(strongSide)
|| pos.count<ROOK>(strongSide)
|| pos.bishop_pair(strongSide))
result += VALUE_KNOWN_WIN;
return strongerSide == pos.side_to_move() ? result : -result;
return strongSide == pos.side_to_move() ? result : -result;
}
@ -165,12 +165,12 @@ Value Endgame<KXK>::operator()(const Position& pos) const {
template<>
Value Endgame<KBNK>::operator()(const Position& pos) const {
assert(verify_material(pos, strongerSide, KnightValueMg + BishopValueMg, 0));
assert(verify_material(pos, weakerSide, VALUE_ZERO, 0));
assert(verify_material(pos, strongSide, KnightValueMg + BishopValueMg, 0));
assert(verify_material(pos, weakSide, VALUE_ZERO, 0));
Square winnerKSq = pos.king_square(strongerSide);
Square loserKSq = pos.king_square(weakerSide);
Square bishopSq = pos.list<BISHOP>(strongerSide)[0];
Square winnerKSq = pos.king_square(strongSide);
Square loserKSq = pos.king_square(weakSide);
Square bishopSq = pos.list<BISHOP>(strongSide)[0];
// kbnk_mate_table() tries to drive toward corners A1 or H8,
// if we have a bishop that cannot reach the above squares we
@ -185,7 +185,7 @@ Value Endgame<KBNK>::operator()(const Position& pos) const {
+ PushClose[square_distance(winnerKSq, loserKSq)]
+ PushToCorners[loserKSq];
return strongerSide == pos.side_to_move() ? result : -result;
return strongSide == pos.side_to_move() ? result : -result;
}
@ -193,15 +193,15 @@ Value Endgame<KBNK>::operator()(const Position& pos) const {
template<>
Value Endgame<KPK>::operator()(const Position& pos) const {
assert(verify_material(pos, strongerSide, VALUE_ZERO, 1));
assert(verify_material(pos, weakerSide, VALUE_ZERO, 0));
assert(verify_material(pos, strongSide, VALUE_ZERO, 1));
assert(verify_material(pos, weakSide, VALUE_ZERO, 0));
Square wksq = pos.king_square(strongerSide);
Square bksq = pos.king_square(weakerSide);
Square psq = pos.list<PAWN>(strongerSide)[0];
Square wksq = pos.king_square(strongSide);
Square bksq = pos.king_square(weakSide);
Square psq = pos.list<PAWN>(strongSide)[0];
Color us = pos.side_to_move();
if (strongerSide == BLACK)
if (strongSide == BLACK)
{
wksq = ~wksq;
bksq = ~bksq;
@ -221,7 +221,7 @@ Value Endgame<KPK>::operator()(const Position& pos) const {
Value result = VALUE_KNOWN_WIN + PawnValueEg + Value(rank_of(psq));
return strongerSide == pos.side_to_move() ? result : -result;
return strongSide == pos.side_to_move() ? result : -result;
}
@ -232,15 +232,15 @@ Value Endgame<KPK>::operator()(const Position& pos) const {
template<>
Value Endgame<KRKP>::operator()(const Position& pos) const {
assert(verify_material(pos, strongerSide, RookValueMg, 0));
assert(verify_material(pos, weakerSide, VALUE_ZERO, 1));
assert(verify_material(pos, strongSide, RookValueMg, 0));
assert(verify_material(pos, weakSide, VALUE_ZERO, 1));
Square wksq = pos.king_square(strongerSide);
Square bksq = pos.king_square(weakerSide);
Square rsq = pos.list<ROOK>(strongerSide)[0];
Square psq = pos.list<PAWN>(weakerSide)[0];
Square wksq = pos.king_square(strongSide);
Square bksq = pos.king_square(weakSide);
Square rsq = pos.list<ROOK>(strongSide)[0];
Square psq = pos.list<PAWN>(weakSide)[0];
if (strongerSide == BLACK)
if (strongSide == BLACK)
{
wksq = ~wksq;
bksq = ~bksq;
@ -257,7 +257,7 @@ Value Endgame<KRKP>::operator()(const Position& pos) const {
// If the weaker side's king is too far from the pawn and the rook,
// it's a win.
else if ( square_distance(bksq, psq) >= 3 + (pos.side_to_move() == weakerSide)
else if ( square_distance(bksq, psq) >= 3 + (pos.side_to_move() == weakSide)
&& square_distance(bksq, rsq) >= 3)
result = RookValueEg - Value(square_distance(wksq, psq));
@ -266,7 +266,7 @@ Value Endgame<KRKP>::operator()(const Position& pos) const {
else if ( rank_of(bksq) <= RANK_3
&& square_distance(bksq, psq) == 1
&& rank_of(wksq) >= RANK_4
&& square_distance(wksq, psq) > 2 + (pos.side_to_move() == strongerSide))
&& square_distance(wksq, psq) > 2 + (pos.side_to_move() == strongSide))
result = Value(80 - square_distance(wksq, psq) * 8);
else
@ -275,7 +275,7 @@ Value Endgame<KRKP>::operator()(const Position& pos) const {
+ Value(square_distance(bksq, psq + DELTA_S) * 8)
+ Value(square_distance(psq, queeningSq) * 8);
return strongerSide == pos.side_to_move() ? result : -result;
return strongSide == pos.side_to_move() ? result : -result;
}
@ -284,11 +284,11 @@ Value Endgame<KRKP>::operator()(const Position& pos) const {
template<>
Value Endgame<KRKB>::operator()(const Position& pos) const {
assert(verify_material(pos, strongerSide, RookValueMg, 0));
assert(verify_material(pos, weakerSide, BishopValueMg, 0));
assert(verify_material(pos, strongSide, RookValueMg, 0));
assert(verify_material(pos, weakSide, BishopValueMg, 0));
Value result = Value(PushToEdges[pos.king_square(weakerSide)]);
return strongerSide == pos.side_to_move() ? result : -result;
Value result = Value(PushToEdges[pos.king_square(weakSide)]);
return strongSide == pos.side_to_move() ? result : -result;
}
@ -297,13 +297,13 @@ Value Endgame<KRKB>::operator()(const Position& pos) const {
template<>
Value Endgame<KRKN>::operator()(const Position& pos) const {
assert(verify_material(pos, strongerSide, RookValueMg, 0));
assert(verify_material(pos, weakerSide, KnightValueMg, 0));
assert(verify_material(pos, strongSide, RookValueMg, 0));
assert(verify_material(pos, weakSide, KnightValueMg, 0));
Square bksq = pos.king_square(weakerSide);
Square bnsq = pos.list<KNIGHT>(weakerSide)[0];
Square bksq = pos.king_square(weakSide);
Square bnsq = pos.list<KNIGHT>(weakSide)[0];
Value result = Value(PushToEdges[bksq] + PushAway[square_distance(bksq, bnsq)]);
return strongerSide == pos.side_to_move() ? result : -result;
return strongSide == pos.side_to_move() ? result : -result;
}
@ -313,21 +313,21 @@ Value Endgame<KRKN>::operator()(const Position& pos) const {
template<>
Value Endgame<KQKP>::operator()(const Position& pos) const {
assert(verify_material(pos, strongerSide, QueenValueMg, 0));
assert(verify_material(pos, weakerSide, VALUE_ZERO, 1));
assert(verify_material(pos, strongSide, QueenValueMg, 0));
assert(verify_material(pos, weakSide, VALUE_ZERO, 1));
Square winnerKSq = pos.king_square(strongerSide);
Square loserKSq = pos.king_square(weakerSide);
Square pawnSq = pos.list<PAWN>(weakerSide)[0];
Square winnerKSq = pos.king_square(strongSide);
Square loserKSq = pos.king_square(weakSide);
Square pawnSq = pos.list<PAWN>(weakSide)[0];
Value result = Value(PushClose[square_distance(winnerKSq, loserKSq)]);
if ( relative_rank(weakerSide, pawnSq) != RANK_7
if ( relative_rank(weakSide, pawnSq) != RANK_7
|| square_distance(loserKSq, pawnSq) != 1
|| !((FileABB | FileCBB | FileFBB | FileHBB) & pawnSq))
result += QueenValueEg - PawnValueEg;
return strongerSide == pos.side_to_move() ? result : -result;
return strongSide == pos.side_to_move() ? result : -result;
}
@ -339,18 +339,18 @@ Value Endgame<KQKP>::operator()(const Position& pos) const {
template<>
Value Endgame<KQKR>::operator()(const Position& pos) const {
assert(verify_material(pos, strongerSide, QueenValueMg, 0));
assert(verify_material(pos, weakerSide, RookValueMg, 0));
assert(verify_material(pos, strongSide, QueenValueMg, 0));
assert(verify_material(pos, weakSide, RookValueMg, 0));
Square winnerKSq = pos.king_square(strongerSide);
Square loserKSq = pos.king_square(weakerSide);
Square winnerKSq = pos.king_square(strongSide);
Square loserKSq = pos.king_square(weakSide);
Value result = QueenValueEg
- RookValueEg
+ PushToEdges[loserKSq]
+ PushClose[square_distance(winnerKSq, loserKSq)];
return strongerSide == pos.side_to_move() ? result : -result;
return strongSide == pos.side_to_move() ? result : -result;
}
@ -361,19 +361,19 @@ Value Endgame<KQKR>::operator()(const Position& pos) const {
template<>
Value Endgame<KBBKN>::operator()(const Position& pos) const {
assert(verify_material(pos, strongerSide, 2 * BishopValueMg, 0));
assert(verify_material(pos, weakerSide, KnightValueMg, 0));
assert(verify_material(pos, strongSide, 2 * BishopValueMg, 0));
assert(verify_material(pos, weakSide, KnightValueMg, 0));
Square winnerKSq = pos.king_square(strongerSide);
Square loserKSq = pos.king_square(weakerSide);
Square knightSq = pos.list<KNIGHT>(weakerSide)[0];
Square winnerKSq = pos.king_square(strongSide);
Square loserKSq = pos.king_square(weakSide);
Square knightSq = pos.list<KNIGHT>(weakSide)[0];
Value result = VALUE_KNOWN_WIN
+ PushToCorners[loserKSq]
+ PushClose[square_distance(winnerKSq, loserKSq)]
+ PushAway[square_distance(loserKSq, knightSq)];
return strongerSide == pos.side_to_move() ? result : -result;
return strongSide == pos.side_to_move() ? result : -result;
}
@ -389,22 +389,22 @@ template<> Value Endgame<KmmKm>::operator()(const Position&) const { return VALU
template<>
ScaleFactor Endgame<KBPsK>::operator()(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == BishopValueMg);
assert(pos.count<PAWN>(strongerSide) >= 1);
assert(pos.non_pawn_material(strongSide) == BishopValueMg);
assert(pos.count<PAWN>(strongSide) >= 1);
// No assertions about the material of weakerSide, because we want draws to
// No assertions about the material of weakSide, because we want draws to
// be detected even when the weaker side has some pawns.
Bitboard pawns = pos.pieces(strongerSide, PAWN);
File pawnFile = file_of(pos.list<PAWN>(strongerSide)[0]);
Bitboard pawns = pos.pieces(strongSide, PAWN);
File pawnFile = file_of(pos.list<PAWN>(strongSide)[0]);
// All pawns are on a single rook file ?
if ( (pawnFile == FILE_A || pawnFile == FILE_H)
&& !(pawns & ~file_bb(pawnFile)))
{
Square bishopSq = pos.list<BISHOP>(strongerSide)[0];
Square queeningSq = relative_square(strongerSide, pawnFile | RANK_8);
Square kingSq = pos.king_square(weakerSide);
Square bishopSq = pos.list<BISHOP>(strongSide)[0];
Square queeningSq = relative_square(strongSide, pawnFile | RANK_8);
Square kingSq = pos.king_square(weakSide);
if ( opposite_colors(queeningSq, bishopSq)
&& abs(file_of(kingSq) - pawnFile) <= 1)
@ -412,12 +412,12 @@ ScaleFactor Endgame<KBPsK>::operator()(const Position& pos) const {
// The bishop has the wrong color, and the defending king is on the
// file of the pawn(s) or the adjacent file. Find the rank of the
// frontmost pawn.
Square pawnSq = frontmost_sq(strongerSide, pawns);
Square pawnSq = frontmost_sq(strongSide, pawns);
// If the defending king has distance 1 to the promotion square or
// is placed somewhere in front of the pawn, it's a draw.
if ( square_distance(kingSq, queeningSq) <= 1
|| relative_rank(weakerSide, kingSq) <= relative_rank(weakerSide, pawnSq))
|| relative_rank(weakSide, kingSq) <= relative_rank(weakSide, pawnSq))
return SCALE_FACTOR_DRAW;
}
}
@ -425,24 +425,24 @@ ScaleFactor Endgame<KBPsK>::operator()(const Position& pos) const {
// All pawns on same B or G file? Then potential draw
if ( (pawnFile == FILE_B || pawnFile == FILE_G)
&& !(pos.pieces(PAWN) & ~file_bb(pawnFile))
&& pos.non_pawn_material(weakerSide) == 0
&& pos.count<PAWN>(weakerSide) >= 1)
&& pos.non_pawn_material(weakSide) == 0
&& pos.count<PAWN>(weakSide) >= 1)
{
// Get weakerSide pawn that is closest to home rank
Square weakerPawnSq = backmost_sq(weakerSide, pos.pieces(weakerSide, PAWN));
// Get weakSide pawn that is closest to home rank
Square weakPawnSq = backmost_sq(weakSide, pos.pieces(weakSide, PAWN));
Square strongerKingSq = pos.king_square(strongerSide);
Square weakerKingSq = pos.king_square(weakerSide);
Square bishopSq = pos.list<BISHOP>(strongerSide)[0];
Square strongKingSq = pos.king_square(strongSide);
Square weakKingSq = pos.king_square(weakSide);
Square bishopSq = pos.list<BISHOP>(strongSide)[0];
// Potential for a draw if our pawn is blocked on the 7th rank
// the bishop cannot attack it or they only have one pawn left
if ( relative_rank(strongerSide, weakerPawnSq) == RANK_7
&& (pos.pieces(strongerSide, PAWN) & (weakerPawnSq + pawn_push(weakerSide)))
&& (opposite_colors(bishopSq, weakerPawnSq) || pos.count<PAWN>(strongerSide) == 1))
if ( relative_rank(strongSide, weakPawnSq) == RANK_7
&& (pos.pieces(strongSide, PAWN) & (weakPawnSq + pawn_push(weakSide)))
&& (opposite_colors(bishopSq, weakPawnSq) || pos.count<PAWN>(strongSide) == 1))
{
int strongerKingDist = square_distance(weakerPawnSq, strongerKingSq);
int weakerKingDist = square_distance(weakerPawnSq, weakerKingSq);
int strongKingDist = square_distance(weakPawnSq, strongKingSq);
int weakKingDist = square_distance(weakPawnSq, weakKingSq);
// Draw if the weak king is on it's back two ranks, within 2
// squares of the blocking pawn and the strong king is not
@ -450,9 +450,9 @@ ScaleFactor Endgame<KBPsK>::operator()(const Position& pos) const {
// unreachable positions such as 5k1K/6p1/6P1/8/8/3B4/8/8 w
// and positions where qsearch will immediately correct the
// problem such as 8/4k1p1/6P1/1K6/3B4/8/8/8 w)
if ( relative_rank(strongerSide, weakerKingSq) >= RANK_7
&& weakerKingDist <= 2
&& weakerKingDist <= strongerKingDist)
if ( relative_rank(strongSide, weakKingSq) >= RANK_7
&& weakKingDist <= 2
&& weakKingDist <= strongKingDist)
return SCALE_FACTOR_DRAW;
}
}
@ -466,19 +466,19 @@ ScaleFactor Endgame<KBPsK>::operator()(const Position& pos) const {
template<>
ScaleFactor Endgame<KQKRPs>::operator()(const Position& pos) const {
assert(verify_material(pos, strongerSide, QueenValueMg, 0));
assert(pos.count<ROOK>(weakerSide) == 1);
assert(pos.count<PAWN>(weakerSide) >= 1);
assert(verify_material(pos, strongSide, QueenValueMg, 0));
assert(pos.count<ROOK>(weakSide) == 1);
assert(pos.count<PAWN>(weakSide) >= 1);
Square kingSq = pos.king_square(weakerSide);
Square rsq = pos.list<ROOK>(weakerSide)[0];
Square kingSq = pos.king_square(weakSide);
Square rsq = pos.list<ROOK>(weakSide)[0];
if ( relative_rank(weakerSide, kingSq) <= RANK_2
&& relative_rank(weakerSide, pos.king_square(strongerSide)) >= RANK_4
&& (pos.pieces(weakerSide, ROOK) & rank_bb(relative_rank(weakerSide, RANK_3)))
&& (pos.pieces(weakerSide, PAWN) & rank_bb(relative_rank(weakerSide, RANK_2)))
&& (pos.attacks_from<KING>(kingSq) & pos.pieces(weakerSide, PAWN))
&& (pos.attacks_from<PAWN>(rsq, strongerSide) & pos.pieces(weakerSide, PAWN)))
if ( relative_rank(weakSide, kingSq) <= RANK_2
&& relative_rank(weakSide, pos.king_square(strongSide)) >= RANK_4
&& (pos.pieces(weakSide, ROOK) & rank_bb(relative_rank(weakSide, RANK_3)))
&& (pos.pieces(weakSide, PAWN) & rank_bb(relative_rank(weakSide, RANK_2)))
&& (pos.attacks_from<KING>(kingSq) & pos.pieces(weakSide, PAWN))
&& (pos.attacks_from<PAWN>(rsq, strongSide) & pos.pieces(weakSide, PAWN)))
return SCALE_FACTOR_DRAW;
return SCALE_FACTOR_NONE;
@ -494,18 +494,18 @@ ScaleFactor Endgame<KQKRPs>::operator()(const Position& pos) const {
template<>
ScaleFactor Endgame<KRPKR>::operator()(const Position& pos) const {
assert(verify_material(pos, strongerSide, RookValueMg, 1));
assert(verify_material(pos, weakerSide, RookValueMg, 0));
assert(verify_material(pos, strongSide, RookValueMg, 1));
assert(verify_material(pos, weakSide, RookValueMg, 0));
Square wksq = pos.king_square(strongerSide);
Square bksq = pos.king_square(weakerSide);
Square wrsq = pos.list<ROOK>(strongerSide)[0];
Square wpsq = pos.list<PAWN>(strongerSide)[0];
Square brsq = pos.list<ROOK>(weakerSide)[0];
Square wksq = pos.king_square(strongSide);
Square bksq = pos.king_square(weakSide);
Square wrsq = pos.list<ROOK>(strongSide)[0];
Square wpsq = pos.list<PAWN>(strongSide)[0];
Square brsq = pos.list<ROOK>(weakSide)[0];
// Orient the board in such a way that the stronger side is white, and the
// pawn is on the left half of the board.
if (strongerSide == BLACK)
if (strongSide == BLACK)
{
wksq = ~wksq;
wrsq = ~wrsq;
@ -526,7 +526,7 @@ ScaleFactor Endgame<KRPKR>::operator()(const Position& pos) const {
File f = file_of(wpsq);
Rank r = rank_of(wpsq);
Square queeningSq = f | RANK_8;
int tempo = (pos.side_to_move() == strongerSide);
int tempo = (pos.side_to_move() == strongSide);
// If the pawn is not too far advanced and the defending king defends the
// queening square, use the third-rank defence.
@ -607,17 +607,17 @@ ScaleFactor Endgame<KRPKR>::operator()(const Position& pos) const {
template<>
ScaleFactor Endgame<KRPKB>::operator()(const Position& pos) const {
assert(verify_material(pos, strongerSide, RookValueMg, 1));
assert(verify_material(pos, weakerSide, BishopValueMg, 0));
assert(verify_material(pos, strongSide, RookValueMg, 1));
assert(verify_material(pos, weakSide, BishopValueMg, 0));
// Test for a rook pawn
if (pos.pieces(PAWN) & (FileABB | FileHBB))
{
Square ksq = pos.king_square(weakerSide);
Square bsq = pos.list<BISHOP>(weakerSide)[0];
Square psq = pos.list<PAWN>(strongerSide)[0];
Rank rk = relative_rank(strongerSide, psq);
Square push = pawn_push(strongerSide);
Square ksq = pos.king_square(weakSide);
Square bsq = pos.list<BISHOP>(weakSide)[0];
Square psq = pos.list<PAWN>(strongSide)[0];
Rank rk = relative_rank(strongSide, psq);
Square push = pawn_push(strongSide);
// If the pawn is on the 5th rank and the pawn (currently) is on
// the same color square as the bishop then there is a chance of
@ -628,7 +628,7 @@ ScaleFactor Endgame<KRPKB>::operator()(const Position& pos) const {
{
int d = square_distance(psq + 3 * push, ksq);
if (d <= 2 && !(d == 0 && ksq == pos.king_square(strongerSide) + 2 * push))
if (d <= 2 && !(d == 0 && ksq == pos.king_square(strongSide) + 2 * push))
return ScaleFactor(24);
else
return ScaleFactor(48);
@ -654,22 +654,22 @@ ScaleFactor Endgame<KRPKB>::operator()(const Position& pos) const {
template<>
ScaleFactor Endgame<KRPPKRP>::operator()(const Position& pos) const {
assert(verify_material(pos, strongerSide, RookValueMg, 2));
assert(verify_material(pos, weakerSide, RookValueMg, 1));
assert(verify_material(pos, strongSide, RookValueMg, 2));
assert(verify_material(pos, weakSide, RookValueMg, 1));
Square wpsq1 = pos.list<PAWN>(strongerSide)[0];
Square wpsq2 = pos.list<PAWN>(strongerSide)[1];
Square bksq = pos.king_square(weakerSide);
Square wpsq1 = pos.list<PAWN>(strongSide)[0];
Square wpsq2 = pos.list<PAWN>(strongSide)[1];
Square bksq = pos.king_square(weakSide);
// Does the stronger side have a passed pawn?
if (pos.pawn_passed(strongerSide, wpsq1) || pos.pawn_passed(strongerSide, wpsq2))
if (pos.pawn_passed(strongSide, wpsq1) || pos.pawn_passed(strongSide, wpsq2))
return SCALE_FACTOR_NONE;
Rank r = std::max(relative_rank(strongerSide, wpsq1), relative_rank(strongerSide, wpsq2));
Rank r = std::max(relative_rank(strongSide, wpsq1), relative_rank(strongSide, wpsq2));
if ( file_distance(bksq, wpsq1) <= 1
&& file_distance(bksq, wpsq2) <= 1
&& relative_rank(strongerSide, bksq) > r)
&& relative_rank(strongSide, bksq) > r)
{
switch (r) {
case RANK_2: return ScaleFactor(10);
@ -689,29 +689,29 @@ ScaleFactor Endgame<KRPPKRP>::operator()(const Position& pos) const {
template<>
ScaleFactor Endgame<KPsK>::operator()(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == VALUE_ZERO);
assert(pos.count<PAWN>(strongerSide) >= 2);
assert(verify_material(pos, weakerSide, VALUE_ZERO, 0));
assert(pos.non_pawn_material(strongSide) == VALUE_ZERO);
assert(pos.count<PAWN>(strongSide) >= 2);
assert(verify_material(pos, weakSide, VALUE_ZERO, 0));
Square ksq = pos.king_square(weakerSide);
Bitboard pawns = pos.pieces(strongerSide, PAWN);
Square ksq = pos.king_square(weakSide);
Bitboard pawns = pos.pieces(strongSide, PAWN);
// Are all pawns on the 'a' file?
if (!(pawns & ~FileABB))
{
// Does the defending king block the pawns?
if ( square_distance(ksq, relative_square(strongerSide, SQ_A8)) <= 1
if ( square_distance(ksq, relative_square(strongSide, SQ_A8)) <= 1
|| ( file_of(ksq) == FILE_A
&& !(in_front_bb(strongerSide, rank_of(ksq)) & pawns)))
&& !(in_front_bb(strongSide, rank_of(ksq)) & pawns)))
return SCALE_FACTOR_DRAW;
}
// Are all pawns on the 'h' file?
else if (!(pawns & ~FileHBB))
{
// Does the defending king block the pawns?
if ( square_distance(ksq, relative_square(strongerSide, SQ_H8)) <= 1
if ( square_distance(ksq, relative_square(strongSide, SQ_H8)) <= 1
|| ( file_of(ksq) == FILE_H
&& !(in_front_bb(strongerSide, rank_of(ksq)) & pawns)))
&& !(in_front_bb(strongSide, rank_of(ksq)) & pawns)))
return SCALE_FACTOR_DRAW;
}
return SCALE_FACTOR_NONE;
@ -725,23 +725,23 @@ ScaleFactor Endgame<KPsK>::operator()(const Position& pos) const {
template<>
ScaleFactor Endgame<KBPKB>::operator()(const Position& pos) const {
assert(verify_material(pos, strongerSide, BishopValueMg, 1));
assert(verify_material(pos, weakerSide, BishopValueMg, 0));
assert(verify_material(pos, strongSide, BishopValueMg, 1));
assert(verify_material(pos, weakSide, BishopValueMg, 0));
Square pawnSq = pos.list<PAWN>(strongerSide)[0];
Square strongerBishopSq = pos.list<BISHOP>(strongerSide)[0];
Square weakerBishopSq = pos.list<BISHOP>(weakerSide)[0];
Square weakerKingSq = pos.king_square(weakerSide);
Square pawnSq = pos.list<PAWN>(strongSide)[0];
Square strongBishopSq = pos.list<BISHOP>(strongSide)[0];
Square weakBishopSq = pos.list<BISHOP>(weakSide)[0];
Square weakKingSq = pos.king_square(weakSide);
// Case 1: Defending king blocks the pawn, and cannot be driven away
if ( file_of(weakerKingSq) == file_of(pawnSq)
&& relative_rank(strongerSide, pawnSq) < relative_rank(strongerSide, weakerKingSq)
&& ( opposite_colors(weakerKingSq, strongerBishopSq)
|| relative_rank(strongerSide, weakerKingSq) <= RANK_6))
if ( file_of(weakKingSq) == file_of(pawnSq)
&& relative_rank(strongSide, pawnSq) < relative_rank(strongSide, weakKingSq)
&& ( opposite_colors(weakKingSq, strongBishopSq)
|| relative_rank(strongSide, weakKingSq) <= RANK_6))
return SCALE_FACTOR_DRAW;
// Case 2: Opposite colored bishops
if (opposite_colors(strongerBishopSq, weakerBishopSq))
if (opposite_colors(strongBishopSq, weakBishopSq))
{
// We assume that the position is drawn in the following three situations:
//
@ -753,17 +753,17 @@ ScaleFactor Endgame<KBPKB>::operator()(const Position& pos) const {
// These rules are probably not perfect, but in practice they work
// reasonably well.
if (relative_rank(strongerSide, pawnSq) <= RANK_5)
if (relative_rank(strongSide, pawnSq) <= RANK_5)
return SCALE_FACTOR_DRAW;
else
{
Bitboard path = forward_bb(strongerSide, pawnSq);
Bitboard path = forward_bb(strongSide, pawnSq);
if (path & pos.pieces(weakerSide, KING))
if (path & pos.pieces(weakSide, KING))
return SCALE_FACTOR_DRAW;
if ( (pos.attacks_from<BISHOP>(weakerBishopSq) & path)
&& square_distance(weakerBishopSq, pawnSq) >= 3)
if ( (pos.attacks_from<BISHOP>(weakBishopSq) & path)
&& square_distance(weakBishopSq, pawnSq) >= 3)
return SCALE_FACTOR_DRAW;
}
}
@ -776,30 +776,30 @@ ScaleFactor Endgame<KBPKB>::operator()(const Position& pos) const {
template<>
ScaleFactor Endgame<KBPPKB>::operator()(const Position& pos) const {
assert(verify_material(pos, strongerSide, BishopValueMg, 2));
assert(verify_material(pos, weakerSide, BishopValueMg, 0));
assert(verify_material(pos, strongSide, BishopValueMg, 2));
assert(verify_material(pos, weakSide, BishopValueMg, 0));
Square wbsq = pos.list<BISHOP>(strongerSide)[0];
Square bbsq = pos.list<BISHOP>(weakerSide)[0];
Square wbsq = pos.list<BISHOP>(strongSide)[0];
Square bbsq = pos.list<BISHOP>(weakSide)[0];
if (!opposite_colors(wbsq, bbsq))
return SCALE_FACTOR_NONE;
Square ksq = pos.king_square(weakerSide);
Square psq1 = pos.list<PAWN>(strongerSide)[0];
Square psq2 = pos.list<PAWN>(strongerSide)[1];
Square ksq = pos.king_square(weakSide);
Square psq1 = pos.list<PAWN>(strongSide)[0];
Square psq2 = pos.list<PAWN>(strongSide)[1];
Rank r1 = rank_of(psq1);
Rank r2 = rank_of(psq2);
Square blockSq1, blockSq2;
if (relative_rank(strongerSide, psq1) > relative_rank(strongerSide, psq2))
if (relative_rank(strongSide, psq1) > relative_rank(strongSide, psq2))
{
blockSq1 = psq1 + pawn_push(strongerSide);
blockSq1 = psq1 + pawn_push(strongSide);
blockSq2 = file_of(psq2) | rank_of(psq1);
}
else
{
blockSq1 = psq2 + pawn_push(strongerSide);
blockSq1 = psq2 + pawn_push(strongSide);
blockSq2 = file_of(psq1) | rank_of(psq2);
}
@ -809,7 +809,7 @@ ScaleFactor Endgame<KBPPKB>::operator()(const Position& pos) const {
// Both pawns are on the same file. Easy draw if defender firmly controls
// some square in the frontmost pawn's path.
if ( file_of(ksq) == file_of(blockSq1)
&& relative_rank(strongerSide, ksq) >= relative_rank(strongerSide, blockSq1)
&& relative_rank(strongSide, ksq) >= relative_rank(strongSide, blockSq1)
&& opposite_colors(ksq, wbsq))
return SCALE_FACTOR_DRAW;
else
@ -822,14 +822,14 @@ ScaleFactor Endgame<KBPPKB>::operator()(const Position& pos) const {
if ( ksq == blockSq1
&& opposite_colors(ksq, wbsq)
&& ( bbsq == blockSq2
|| (pos.attacks_from<BISHOP>(blockSq2) & pos.pieces(weakerSide, BISHOP))
|| (pos.attacks_from<BISHOP>(blockSq2) & pos.pieces(weakSide, BISHOP))
|| abs(r1 - r2) >= 2))
return SCALE_FACTOR_DRAW;
else if ( ksq == blockSq2
&& opposite_colors(ksq, wbsq)
&& ( bbsq == blockSq1
|| (pos.attacks_from<BISHOP>(blockSq1) & pos.pieces(weakerSide, BISHOP))))
|| (pos.attacks_from<BISHOP>(blockSq1) & pos.pieces(weakSide, BISHOP))))
return SCALE_FACTOR_DRAW;
else
return SCALE_FACTOR_NONE;
@ -847,17 +847,17 @@ ScaleFactor Endgame<KBPPKB>::operator()(const Position& pos) const {
template<>
ScaleFactor Endgame<KBPKN>::operator()(const Position& pos) const {
assert(verify_material(pos, strongerSide, BishopValueMg, 1));
assert(verify_material(pos, weakerSide, KnightValueMg, 0));
assert(verify_material(pos, strongSide, BishopValueMg, 1));
assert(verify_material(pos, weakSide, KnightValueMg, 0));
Square pawnSq = pos.list<PAWN>(strongerSide)[0];
Square strongerBishopSq = pos.list<BISHOP>(strongerSide)[0];
Square weakerKingSq = pos.king_square(weakerSide);
Square pawnSq = pos.list<PAWN>(strongSide)[0];
Square strongBishopSq = pos.list<BISHOP>(strongSide)[0];
Square weakKingSq = pos.king_square(weakSide);
if ( file_of(weakerKingSq) == file_of(pawnSq)
&& relative_rank(strongerSide, pawnSq) < relative_rank(strongerSide, weakerKingSq)
&& ( opposite_colors(weakerKingSq, strongerBishopSq)
|| relative_rank(strongerSide, weakerKingSq) <= RANK_6))
if ( file_of(weakKingSq) == file_of(pawnSq)
&& relative_rank(strongSide, pawnSq) < relative_rank(strongSide, weakKingSq)
&& ( opposite_colors(weakKingSq, strongBishopSq)
|| relative_rank(strongSide, weakKingSq) <= RANK_6))
return SCALE_FACTOR_DRAW;
return SCALE_FACTOR_NONE;
@ -870,18 +870,18 @@ ScaleFactor Endgame<KBPKN>::operator()(const Position& pos) const {
template<>
ScaleFactor Endgame<KNPK>::operator()(const Position& pos) const {
assert(verify_material(pos, strongerSide, KnightValueMg, 1));
assert(verify_material(pos, weakerSide, VALUE_ZERO, 0));
assert(verify_material(pos, strongSide, KnightValueMg, 1));
assert(verify_material(pos, weakSide, VALUE_ZERO, 0));
Square pawnSq = pos.list<PAWN>(strongerSide)[0];
Square weakerKingSq = pos.king_square(weakerSide);
Square pawnSq = pos.list<PAWN>(strongSide)[0];
Square weakKingSq = pos.king_square(weakSide);
if ( pawnSq == relative_square(strongerSide, SQ_A7)
&& square_distance(weakerKingSq, relative_square(strongerSide, SQ_A8)) <= 1)
if ( pawnSq == relative_square(strongSide, SQ_A7)
&& square_distance(weakKingSq, relative_square(strongSide, SQ_A8)) <= 1)
return SCALE_FACTOR_DRAW;
if ( pawnSq == relative_square(strongerSide, SQ_H7)
&& square_distance(weakerKingSq, relative_square(strongerSide, SQ_H8)) <= 1)
if ( pawnSq == relative_square(strongSide, SQ_H7)
&& square_distance(weakKingSq, relative_square(strongSide, SQ_H8)) <= 1)
return SCALE_FACTOR_DRAW;
return SCALE_FACTOR_NONE;
@ -893,14 +893,14 @@ ScaleFactor Endgame<KNPK>::operator()(const Position& pos) const {
template<>
ScaleFactor Endgame<KNPKB>::operator()(const Position& pos) const {
Square pawnSq = pos.list<PAWN>(strongerSide)[0];
Square bishopSq = pos.list<BISHOP>(weakerSide)[0];
Square weakerKingSq = pos.king_square(weakerSide);
Square pawnSq = pos.list<PAWN>(strongSide)[0];
Square bishopSq = pos.list<BISHOP>(weakSide)[0];
Square weakKingSq = pos.king_square(weakSide);
// King needs to get close to promoting pawn to prevent knight from blocking.
// Rules for this are very tricky, so just approximate.
if (forward_bb(strongerSide, pawnSq) & pos.attacks_from<BISHOP>(bishopSq))
return ScaleFactor(square_distance(weakerKingSq, pawnSq));
if (forward_bb(strongSide, pawnSq) & pos.attacks_from<BISHOP>(bishopSq))
return ScaleFactor(square_distance(weakKingSq, pawnSq));
return SCALE_FACTOR_NONE;
}
@ -914,15 +914,15 @@ ScaleFactor Endgame<KNPKB>::operator()(const Position& pos) const {
template<>
ScaleFactor Endgame<KPKP>::operator()(const Position& pos) const {
assert(verify_material(pos, strongerSide, VALUE_ZERO, 1));
assert(verify_material(pos, weakerSide, VALUE_ZERO, 1));
assert(verify_material(pos, strongSide, VALUE_ZERO, 1));
assert(verify_material(pos, weakSide, VALUE_ZERO, 1));
Square wksq = pos.king_square(strongerSide);
Square bksq = pos.king_square(weakerSide);
Square psq = pos.list<PAWN>(strongerSide)[0];
Square wksq = pos.king_square(strongSide);
Square bksq = pos.king_square(weakSide);
Square psq = pos.list<PAWN>(strongSide)[0];
Color us = pos.side_to_move();
if (strongerSide == BLACK)
if (strongSide == BLACK)
{
wksq = ~wksq;
bksq = ~bksq;

6
src/endgame.h
View file

@ -86,12 +86,12 @@ struct EndgameBase {
template<EndgameType E, typename T = typename eg_fun<(E > SCALE_FUNS)>::type>
struct Endgame : public EndgameBase<T> {
explicit Endgame(Color c) : strongerSide(c), weakerSide(~c) {}
Color color() const { return strongerSide; }
explicit Endgame(Color c) : strongSide(c), weakSide(~c) {}
Color color() const { return strongSide; }
T operator()(const Position&) const;
private:
Color strongerSide, weakerSide;
Color strongSide, weakSide;
};