X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fevaluate.cpp;h=ba3ea9fb4def53ac2351033c3227d3cf7b1455f4;hp=afe2bd6666d57a7b79d2cc395a7fb4b844411f75;hb=181d34e5a028ab5ff1d55a6f395dd2d13dcc8809;hpb=ed19a9f909b5a26dfde49d37c7622b6a385ea18d diff --git a/src/evaluate.cpp b/src/evaluate.cpp index afe2bd66..ba3ea9fb 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -366,7 +366,8 @@ Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID) { // Evaluate passed pawns. We evaluate passed pawns for both sides at once, // because we need to know which side promotes first in positions where - // both sides have an unstoppable passed pawn. + // both sides have an unstoppable passed pawn. To be called after all attacks + // are computed, included king. if (ei.pi->passed_pawns()) evaluate_passed_pawns(pos, ei); @@ -892,7 +893,7 @@ namespace { // evaluate_passed_pawns() evaluates the passed pawns of the given color template - void evaluate_passed_pawns_of_color(const Position& pos, bool hasUnstoppable[], int movesToGo[], EvalInfo& ei) { + void evaluate_passed_pawns_of_color(const Position& pos, int movesToGo[], Square pawnToGo[], EvalInfo& ei) { const Color Them = (Us == WHITE ? BLACK : WHITE); @@ -910,15 +911,16 @@ namespace { int r = int(relative_rank(Us, s) - RANK_2); int tr = Max(0, r * (r - 1)); - Square blockSq = s + pawn_push(Us); // Base bonus based on rank Value mbonus = Value(20 * tr); Value ebonus = Value(10 + r * r * 10); // Adjust bonus based on king proximity - if (tr != 0) + if (tr) { + Square blockSq = s + pawn_push(Us); + ebonus -= Value(square_distance(ourKingSq, blockSq) * 3 * tr); ebonus -= Value(square_distance(ourKingSq, blockSq + pawn_push(Us)) * 1 * tr); ebonus += Value(square_distance(theirKingSq, blockSq) * 6 * tr); @@ -926,29 +928,31 @@ namespace { // If the pawn is free to advance, increase bonus if (pos.square_is_empty(blockSq)) { + // There are no enemy pawns in the pawn's path b2 = squares_in_front_of(Us, s); - b3 = b2 & ei.attacked_by(Them); + + assert((b2 & pos.pieces(PAWN, Them)) == EmptyBoardBB); + + // Squares attacked by us b4 = b2 & ei.attacked_by(Us); + // Squares attacked or occupied by enemy pieces + b3 = b2 & (ei.attacked_by(Them) | pos.pieces_of_color(Them)); + // If there is an enemy rook or queen attacking the pawn from behind, // add all X-ray attacks by the rook or queen. - if ( bit_is_set(ei.attacked_by(Them, ROOK) | ei.attacked_by(Them, QUEEN), s) - && (squares_behind(Us, s) & pos.pieces(ROOK, QUEEN, Them))) + if ( (squares_behind(Us, s) & pos.pieces(ROOK, QUEEN, Them)) + && (squares_behind(Us, s) & pos.pieces(ROOK, QUEEN, Them) & pos.attacks_from(s))) b3 = b2; - // Squares attacked or occupied by enemy pieces - b3 |= (b2 & pos.pieces_of_color(Them)); - - // There are no enemy pawns in the pawn's path - assert((b2 & pos.pieces(PAWN, Them)) == EmptyBoardBB); - // Are any of the squares in the pawn's path attacked or occupied by the enemy? if (b3 == EmptyBoardBB) // No enemy attacks or pieces, huge bonus! + // Even bigger if we protect the pawn's path ebonus += Value(tr * (b2 == b4 ? 17 : 15)); else // OK, there are enemy attacks or pieces (but not pawns). Are those - // squares which are attacked by the enemy also attacked by us? + // squares which are attacked by the enemy also attacked by us ? // If yes, big bonus (but smaller than when there are no enemy attacks), // if no, somewhat smaller bonus. ebonus += Value(tr * ((b3 & b4) == b3 ? 13 : 8)); @@ -985,10 +989,10 @@ namespace { int blockerCount = count_1s_max_15(squares_in_front_of(Us,s) & pos.occupied_squares()); mtg += blockerCount; d += blockerCount; - if (d < 0) + if (d < 0 && (!movesToGo[Us] || movesToGo[Us] > mtg)) { - hasUnstoppable[Us] = true; - movesToGo[Us] = Min(movesToGo[Us], mtg); + movesToGo[Us] = mtg; + pawnToGo[Us] = s; } } } @@ -1020,39 +1024,56 @@ namespace { void evaluate_passed_pawns(const Position& pos, EvalInfo& ei) { - bool hasUnstoppable[2] = {false, false}; - int movesToGo[2] = {100, 100}; + int movesToGo[2] = {0, 0}; + Square pawnToGo[2] = {SQ_NONE, SQ_NONE}; // Evaluate pawns for each color - evaluate_passed_pawns_of_color(pos, hasUnstoppable, movesToGo, ei); - evaluate_passed_pawns_of_color(pos, hasUnstoppable, movesToGo, ei); - - // Does either side have an unstoppable passed pawn? - if (hasUnstoppable[WHITE] && !hasUnstoppable[BLACK]) - ei.egValue += UnstoppablePawnValue - Value(0x40 * movesToGo[WHITE]); - else if (hasUnstoppable[BLACK] && !hasUnstoppable[WHITE]) - ei.egValue -= UnstoppablePawnValue - Value(0x40 * movesToGo[BLACK]); - else if (hasUnstoppable[BLACK] && hasUnstoppable[WHITE]) + evaluate_passed_pawns_of_color(pos, movesToGo, pawnToGo, ei); + evaluate_passed_pawns_of_color(pos, movesToGo, pawnToGo, ei); + + // Neither side has an unstoppable passed pawn? + if (!(movesToGo[WHITE] | movesToGo[BLACK])) + return; + + // Does only one side have an unstoppable passed pawn? + if (!movesToGo[WHITE] || !movesToGo[BLACK]) { - // Both sides have unstoppable pawns! Try to find out who queens + Color winnerSide = movesToGo[WHITE] ? WHITE : BLACK; + ei.egValue += Sign[winnerSide] * (UnstoppablePawnValue - Value(0x40 * movesToGo[winnerSide])); + } + else + { // Both sides have unstoppable pawns! Try to find out who queens // first. We begin by transforming 'movesToGo' to the number of // plies until the pawn queens for both sides. movesToGo[WHITE] *= 2; movesToGo[BLACK] *= 2; movesToGo[pos.side_to_move()]--; - // If one side queens at least three plies before the other, that - // side wins. - if (movesToGo[WHITE] <= movesToGo[BLACK] - 3) - ei.egValue += UnstoppablePawnValue - Value(0x40 * (movesToGo[WHITE]/2)); - else if (movesToGo[BLACK] <= movesToGo[WHITE] - 3) - ei.egValue -= UnstoppablePawnValue - Value(0x40 * (movesToGo[BLACK]/2)); - - // We could also add some rules about the situation when one side - // queens exactly one ply before the other: Does the first queen - // check the opponent's king, or attack the opponent's queening square? - // This is slightly tricky to get right, because it is possible that - // the opponent's king has moved somewhere before the first pawn queens. + Color winnerSide = movesToGo[WHITE] < movesToGo[BLACK] ? WHITE : BLACK; + Color loserSide = opposite_color(winnerSide); + + // If one side queens at least three plies before the other, that side wins + if (movesToGo[winnerSide] <= movesToGo[loserSide] - 3) + ei.egValue += Sign[winnerSide] * (UnstoppablePawnValue - Value(0x40 * (movesToGo[winnerSide]/2))); + + // If one side queens one ply before the other and checks the king or attacks + // the undefended opponent's queening square, that side wins. To avoid cases + // where the opponent's king could move somewhere before first pawn queens we + // consider only free paths to queen for both pawns. + else if ( !(squares_in_front_of(WHITE, pawnToGo[WHITE]) & pos.occupied_squares()) + && !(squares_in_front_of(BLACK, pawnToGo[BLACK]) & pos.occupied_squares())) + { + assert(movesToGo[loserSide] - movesToGo[winnerSide] == 1); + + Square winnerQSq = relative_square(winnerSide, make_square(square_file(pawnToGo[winnerSide]), RANK_8)); + Square loserQSq = relative_square(loserSide, make_square(square_file(pawnToGo[loserSide]), RANK_8)); + + Bitboard b = pos.attacks_from(winnerQSq); + + if ( (b & pos.pieces(KING, loserSide)) + ||(bit_is_set(b, loserQSq) && !bit_is_set(ei.attacked_by(loserSide), loserQSq))) + ei.egValue += Sign[winnerSide] * (UnstoppablePawnValue - Value(0x40 * (movesToGo[winnerSide]/2))); + } } }