X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fpawns.cpp;h=3ce896309f530f057daeacf6320bb35d9eb26517;hp=8759631ac6c43102fa7ed6d11770cc1820530300;hb=fb8095718bd0789d2743fa6216c6aa522555dc4b;hpb=209e94203f8c4d0a48405192d1e71c80f28f3159 diff --git a/src/pawns.cpp b/src/pawns.cpp index 8759631a..3ce89630 100644 --- a/src/pawns.cpp +++ b/src/pawns.cpp @@ -33,12 +33,13 @@ namespace { // Pawn penalties constexpr Score Backward = S( 9, 24); - constexpr Score BlockedStorm = S(82, 82); constexpr Score Doubled = S(11, 56); constexpr Score Isolated = S( 5, 15); constexpr Score WeakLever = S( 0, 56); constexpr Score WeakUnopposed = S(13, 27); + constexpr Score BlockedStorm[RANK_NB] = {S( 0, 0), S( 0, 0), S( 76, 78), S(-10, 15), S(-7, 10), S(-4, 6), S(-1, 2)}; + // Connected pawn bonus constexpr int Connected[RANK_NB] = { 0, 7, 8, 12, 29, 48, 86 }; @@ -86,6 +87,7 @@ namespace { e->passedPawns[Us] = 0; e->kingSquares[Us] = SQ_NONE; e->pawnAttacks[Us] = e->pawnAttacksSpan[Us] = pawn_attacks_bb(ourPawns); + e->blockedCount += popcount(shift(ourPawns) & (theirPawns | doubleAttackThem)); // Loop through all pawns of the current color and score each pawn while ((s = *pl++) != SQ_NONE) @@ -118,6 +120,7 @@ namespace { // (a) there is no stoppers except some levers // (b) the only stoppers are the leverPush, but we outnumber them // (c) there is only one front stopper which can be levered. + // (Refined in Evaluation::passed) passed = !(stoppers ^ lever) || ( !(stoppers ^ leverPush) && popcount(phalanx) >= popcount(leverPush)) @@ -134,16 +137,23 @@ namespace { // Score this pawn if (support | phalanx) { - int v = Connected[r] * (2 + bool(phalanx) - bool(opposed)) + int v = Connected[r] * (4 + 2 * bool(phalanx) - 2 * bool(opposed) - bool(blocked)) / 2 + 21 * popcount(support); score += make_score(v, v * (r - 2) / 4); } else if (!neighbours) + { score -= Isolated + WeakUnopposed * !opposed; + if ( (ourPawns & forward_file_bb(Them, s)) + && popcount(opposed) == 1 + && !(theirPawns & adjacent_files_bb(s))) + score -= Doubled; + } + else if (backward) score -= Backward + WeakUnopposed * !opposed; @@ -174,6 +184,7 @@ Entry* probe(const Position& pos) { return e; e->key = key; + e->blockedCount = 0; e->scores[WHITE] = evaluate(pos, e); e->scores[BLACK] = evaluate(pos, e); @@ -190,7 +201,7 @@ Score Entry::evaluate_shelter(const Position& pos, Square ksq) { constexpr Color Them = ~Us; Bitboard b = pos.pieces(PAWN) & ~forward_ranks_bb(Them, ksq); - Bitboard ourPawns = b & pos.pieces(Us); + Bitboard ourPawns = b & pos.pieces(Us) & ~pawnAttacks[Them]; Bitboard theirPawns = b & pos.pieces(Them); Score bonus = make_score(5, 5); @@ -204,11 +215,11 @@ Score Entry::evaluate_shelter(const Position& pos, Square ksq) { b = theirPawns & file_bb(f); int theirRank = b ? relative_rank(Us, frontmost_sq(Them, b)) : 0; - File d = edge_distance(f); + int d = edge_distance(f); bonus += make_score(ShelterStrength[d][ourRank], 0); if (ourRank && (ourRank == theirRank - 1)) - bonus -= BlockedStorm * int(theirRank == RANK_3); + bonus -= BlockedStorm[theirRank]; else bonus -= make_score(UnblockedStorm[d][theirRank], 0); } @@ -240,7 +251,7 @@ Score Entry::do_king_safety(const Position& pos) { // In endgame we like to bring our king near our closest pawn Bitboard pawns = pos.pieces(Us, PAWN); - int minPawnDist = pawns ? 8 : 0; + int minPawnDist = 6; if (pawns & PseudoAttacks[KING][ksq]) minPawnDist = 1;