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Correct Pawn Trace Score + Code Clean up

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No functional change

Resolves #542
This commit is contained in:
Alain SAVARD
2015-12-30 11:29:25 +00:00
committed by Joona Kiiski
parent 3e4fed3a91
commit 6a79d5d10e
4 changed files with 85 additions and 84 deletions
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src/evaluate.cpp
+40 -39
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@@ -111,8 +111,7 @@ namespace {
enum { PawnStructure, PassedPawns, Space, KingSafety };
const struct Weight { int mg, eg; } Weights[] = {
{214, 203}, {193, 262}, {47, 0}, {330, 0}
};
{214, 203}, {193, 262}, {47, 0}, {330, 0} };
Score operator*(Score s, const Weight& w) {
return make_score(mg_value(s) * w.mg / 256, eg_value(s) * w.eg / 256);
@@ -156,19 +155,26 @@ namespace {
{ S( 8, 2), S(13, 4) } // Bishops
};
// Threat[minor/rook][attacked PieceType] contains
// RookOnFile[semiopen/open] contains bonuses for each rook when there is no
// friendly pawn on the rook file.
const Score RookOnFile[2] = { S(19, 10), S(43, 21) };
// ThreatBySafePawn[PieceType] contains bonuses according to which piece
// type is attacked by a pawn which is protected or not attacked.
const Score ThreatBySafePawn[PIECE_TYPE_NB] = {
S(0, 0), S(0, 0), S(176, 139), S(131, 127), S(217, 218), S(203, 215) };
// Threat[by minor/by rook][attacked PieceType] contains
// bonuses according to which piece type attacks which one.
// Attacks on lesser pieces which are pawn defended are not considered.
const Score Threat[2][PIECE_TYPE_NB] = {
{ S(0, 0), S(0, 33), S(45, 43), S(46, 47), S(72, 107), S(48,118) }, // Minor attacks
{ S(0, 0), S(0, 25), S(40, 62), S(40, 59), S( 0, 34), S(35, 48) } // Rook attacks
const Score Threat[][PIECE_TYPE_NB] = {
{ S(0, 0), S(0, 33), S(45, 43), S(46, 47), S(72,107), S(48,118) }, // by Minor
{ S(0, 0), S(0, 25), S(40, 62), S(40, 59), S( 0, 34), S(35, 48) } // by Rook
};
// ThreatenedByPawn[PieceType] contains a penalty according to which piece
// type is attacked by a pawn.
const Score ThreatenedByPawn[PIECE_TYPE_NB] = {
S(0, 0), S(0, 0), S(176, 139), S(131, 127), S(217, 218), S(203, 215)
};
// ThreatByKing[on one/on many] contains bonuses for King attacks on
// pawns or pieces which are not pawn defended.
const Score ThreatByKing[2] = { S(3, 62), S(9, 138) };
// Passed[mg/eg][Rank] contains midgame and endgame bonuses for passed pawns.
// We don't use a Score because we process the two components independently.
@@ -177,27 +183,22 @@ namespace {
{ V(7), V(14), V(37), V(63), V(134), V(189) }
};
// PassedFile[File] contains a bonus according to the file of a passed pawn.
const Score PassedFile[] = {
S( 12, 10), S( 3, 10), S( 1, -8), S(-27, -12),
S(-27, -12), S( 1, -8), S( 3, 10), S( 12, 10)
// PassedFile[File] contains a bonus according to the file of a passed pawn
const Score PassedFile[FILE_NB] = {
S( 12, 10), S( 3, 10), S( 1, -8), S(-27,-12),
S(-27,-12), S( 1, -8), S( 3, 10), S( 12, 10)
};
const Score ThreatenedByHangingPawn = S(70, 63);
// Assorted bonuses and penalties used by evaluation
const Score KingOnOne = S( 3, 62);
const Score KingOnMany = S( 9,138);
const Score RookOnPawn = S( 7, 27);
const Score RookOnOpenFile = S(43, 21);
const Score RookOnSemiOpenFile = S(19, 10);
const Score BishopPawns = S( 8, 12);
const Score MinorBehindPawn = S(16, 0);
const Score TrappedRook = S(92, 0);
const Score Unstoppable = S( 0, 20);
const Score Hanging = S(48, 28);
const Score PawnAttackThreat = S(31, 19);
const Score Checked = S(20, 20);
const Score MinorBehindPawn = S(16, 0);
const Score BishopPawns = S( 8, 12);
const Score RookOnPawn = S( 7, 27);
const Score TrappedRook = S(92, 0);
const Score Checked = S(20, 20);
const Score ThreatByHangingPawn = S(70, 63);
const Score Hanging = S(48, 28);
const Score ThreatByPawnPush = S(31, 19);
const Score Unstoppable = S( 0, 20);
// Penalty for a bishop on a1/h1 (a8/h8 for black) which is trapped by
// a friendly pawn on b2/g2 (b7/g7 for black). This can obviously only
@@ -343,15 +344,15 @@ namespace {
{
Bitboard alignedPawns = pos.pieces(Them, PAWN) & PseudoAttacks[ROOK][s];
if (alignedPawns)
score += popcount<Max15>(alignedPawns) * RookOnPawn;
score += RookOnPawn * popcount<Max15>(alignedPawns);
}
// Bonus when on an open or semi-open file
if (ei.pi->semiopen_file(Us, file_of(s)))
score += ei.pi->semiopen_file(Them, file_of(s)) ? RookOnOpenFile : RookOnSemiOpenFile;
score += RookOnFile[!!ei.pi->semiopen_file(Them, file_of(s))];
// Penalize when trapped by the king, even more if king cannot castle
if (mob <= 3 && !ei.pi->semiopen_file(Us, file_of(s)))
else if (mob <= 3)
{
Square ksq = pos.square<KING>(Us);
@@ -506,10 +507,10 @@ namespace {
safeThreats = (shift_bb<Right>(b) | shift_bb<Left>(b)) & weak;
if (weak ^ safeThreats)
score += ThreatenedByHangingPawn;
score += ThreatByHangingPawn;
while (safeThreats)
score += ThreatenedByPawn[type_of(pos.piece_on(pop_lsb(&safeThreats)))];
score += ThreatBySafePawn[type_of(pos.piece_on(pop_lsb(&safeThreats)))];
}
// Non-pawn enemies defended by a pawn
@@ -537,7 +538,7 @@ namespace {
b = weak & ei.attackedBy[Us][KING];
if (b)
score += more_than_one(b) ? KingOnMany : KingOnOne;
score += ThreatByKing[more_than_one(b)];
}
// Bonus if some pawns can safely push and attack an enemy piece
@@ -553,7 +554,7 @@ namespace {
& ~ei.attackedBy[Us][PAWN];
if (b)
score += popcount<Max15>(b) * PawnAttackThreat;
score += ThreatByPawnPush * popcount<Max15>(b);
if (DoTrace)
Trace::add(THREAT, Us, score);
@@ -811,10 +812,10 @@ Value Eval::evaluate(const Position& pos) {
{
Bitboard b;
if ((b = ei.pi->passed_pawns(WHITE)) != 0)
score += int(relative_rank(WHITE, frontmost_sq(WHITE, b))) * Unstoppable;
score += Unstoppable * int(relative_rank(WHITE, frontmost_sq(WHITE, b)));
if ((b = ei.pi->passed_pawns(BLACK)) != 0)
score -= int(relative_rank(BLACK, frontmost_sq(BLACK, b))) * Unstoppable;
score -= Unstoppable * int(relative_rank(BLACK, frontmost_sq(BLACK, b)));
}
// Evaluate space for both sides, only during opening
@@ -839,7 +840,7 @@ Value Eval::evaluate(const Position& pos) {
{
Trace::add(MATERIAL, pos.psq_score());
Trace::add(IMBALANCE, ei.me->imbalance());
Trace::add(PAWN, ei.pi->pawns_score());
Trace::add(PAWN, ei.pi->pawns_score() * Weights[PawnStructure]);
Trace::add(MOBILITY, mobility[WHITE], mobility[BLACK]);
Trace::add(SPACE, evaluate_space<WHITE>(pos, ei) * Weights[Space]
, evaluate_space<BLACK>(pos, ei) * Weights[Space]);