/* * eval.c - C source for GNU CHESS * * Copyright (c) 1988,1989,1990 John Stanback * Copyright (c) 1992 Free Software Foundation * * This file is part of GNU CHESS. * * GNU Chess 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 2, or (at your option) * any later version. * * GNU Chess 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. * * You should have received a copy of the GNU General Public License * along with GNU Chess; see the file COPYING. If not, write to * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ #include "gnuchess.h" #include "ataks.h" short int sscore[2]; /* Backward pawn bonus indexed by # of attackers on the square */ static const short BACKWARD[16] = {-6, -10, -15, -21, -28, -28, -28, -28, -28, -28, -28, -28, -28, -28, -28, -28}; /* Bishop mobility bonus indexed by # reachable squares */ static const short BMBLTY[14] = {-2, 0, 2, 4, 6, 8, 10, 12, 13, 14, 15, 16, 16, 16}; /* Rook mobility bonus indexed by # reachable squares */ static const short RMBLTY[15] = {0, 2, 4, 6, 8, 10, 11, 12, 13, 14, 14, 14, 14, 14, 14}; /* Positional values for a dying king */ static const short DyingKing[64] = {0, 8, 16, 24, 24, 16, 8, 0, 8, 32, 40, 48, 48, 40, 32, 8, 16, 40, 56, 64, 64, 56, 40, 16, 24, 48, 64, 72, 72, 64, 48, 24, 24, 48, 64, 72, 72, 64, 48, 24, 16, 40, 56, 64, 64, 56, 40, 16, 8, 32, 40, 48, 48, 40, 32, 8, 0, 8, 16, 24, 24, 16, 8, 0}; /* Isoloted pawn penalty by rank */ static const short ISOLANI[8] = {-12, -16, -20, -24, -24, -20, -16, -12}; /* table for King Bishop Knight endings */ static const short KBNK[64] = {99, 90, 80, 70, 60, 50, 40, 40, 90, 80, 60, 50, 40, 30, 20, 40, 80, 60, 40, 30, 20, 10, 30, 50, 70, 50, 30, 10, 0, 20, 40, 60, 60, 40, 20, 0, 10, 30, 50, 70, 50, 30, 10, 20, 30, 40, 60, 80, 40, 20, 30, 40, 50, 60, 80, 90, 40, 40, 50, 60, 70, 80, 90, 99}; /* penalty for threats to king, indexed by number of such threats */ static const short KTHRT[36] = {0, -8, -20, -36, -52, -68, -80, -80, -80, -80, -80, -80, -80, -80, -80, -80, -80, -80, -80, -80, -80, -80, -80, -80, -80, -80, -80, -80, -80, -80, -80, -80, -80, -80, -80, -80}; /* King positional bonus inopening stage */ static const short KingOpening[64] = {0, 0, -4, -10, -10, -4, 0, 0, -4, -4, -8, -12, -12, -8, -4, -4, -12, -16, -20, -20, -20, -20, -16, -12, -16, -20, -24, -24, -24, -24, -20, -16, -16, -20, -24, -24, -24, -24, -20, -16, -12, -16, -20, -20, -20, -20, -16, -12, -4, -4, -8, -12, -12, -8, -4, -4, 0, 0, -4, -10, -10, -4, 0, 0}; /* King positional bonus in end stage */ static const short KingEnding[64] = {0, 6, 12, 18, 18, 12, 6, 0, 6, 12, 18, 24, 24, 18, 12, 6, 12, 18, 24, 30, 30, 24, 18, 12, 18, 24, 30, 36, 36, 30, 24, 18, 18, 24, 30, 36, 36, 30, 24, 18, 12, 18, 24, 30, 30, 24, 18, 12, 6, 12, 18, 24, 24, 18, 12, 6, 0, 6, 12, 18, 18, 12, 6, 0}; /* Passed pawn positional bonus */ static const short PassedPawn0[8] = {0, 60, 80, 120, 200, 360, 600, 800}; static const short PassedPawn1[8] = {0, 30, 40, 60, 100, 180, 300, 800}; static const short PassedPawn2[8] = {0, 15, 25, 35, 50, 90, 140, 800}; static const short PassedPawn3[8] = {0, 5, 10, 15, 20, 30, 140, 800}; /* Knight positional bonus */ static const short pknight[64] = {0, 4, 8, 10, 10, 8, 4, 0, 4, 8, 16, 20, 20, 16, 8, 4, 8, 16, 24, 28, 28, 24, 16, 8, 10, 20, 28, 32, 32, 28, 20, 10, 10, 20, 28, 32, 32, 28, 20, 10, 8, 16, 24, 28, 28, 24, 16, 8, 4, 8, 16, 20, 20, 16, 8, 4, 0, 4, 8, 10, 10, 8, 4, 0}; /* Bishop positional bonus */ static const short pbishop[64] = {14, 14, 14, 14, 14, 14, 14, 14, 14, 22, 18, 18, 18, 18, 22, 14, 14, 18, 22, 22, 22, 22, 18, 14, 14, 18, 22, 22, 22, 22, 18, 14, 14, 18, 22, 22, 22, 22, 18, 14, 14, 18, 22, 22, 22, 22, 18, 14, 14, 22, 18, 18, 18, 18, 22, 14, 14, 14, 14, 14, 14, 14, 14, 14}; /* Pawn positional bonus */ static const short PawnAdvance[64] = {0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 4, 0, 0, 4, 4, 4, 6, 8, 2, 10, 10, 2, 8, 6, 6, 8, 12, 16, 16, 12, 8, 6, 8, 12, 16, 24, 24, 16, 12, 8, 12, 16, 24, 32, 32, 24, 16, 12, 12, 16, 24, 32, 32, 24, 16, 12, 0, 0, 0, 0, 0, 0, 0, 0}; #if !defined NOSCORESPACE #ifdef BLACKAG0 /* Space positional bonus */ static const short SpaceBonusB[64] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 2, 2, 0, 0, 1, 1, 2, 4, 4, 2, 1, 1, 0, 0, 3, 4, 4, 3, 0, 0, 0, 0, 5, 5, 5, 5, 0, 0, 0, 0, 4, 4, 7, 7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}; #elif defined BLACKAG1 /* Space positional bonus */ static const short SpaceBonusB[64] = {1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 1, 1, 1, 1, 2, 3, 3, 2, 1, 1, 1, 1, 2, 4, 4, 2, 1, 1, 1, 1, 3, 5, 5, 3, 1, 1, 1, 1, 3, 6, 6, 3, 1, 1, 1, 1, 3, 7, 7, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}; #elif defined BLACKAG2 /* Space positional bonus */ static const short SpaceBonusB[64] = {1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 1, 1, 1, 1, 3, 3, 3, 3, 1, 1, 1, 1, 4, 4, 4, 4, 1, 1, 1, 1, 5, 6, 6, 5, 1, 1, 1, 1, 6, 7, 7, 6, 1, 1, 1, 1, 7, 8, 8, 7, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}; #elif defined BLACKAG3 /* Space positional bonus */ static const short SpaceBonusB[64] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 2, 2, 0, 0, 0, 0, 3, 3, 3, 3, 0, 0, 0, 0, 4, 4, 4, 3, 0, 0, 0, 0, 6, 6, 4, 4, 0, 0, 0, 0, 7, 7, 5, 5, 0, 0, 0, 0, 8, 8, 7, 7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}; #elif defined BLACKAG4 /* Space positional bonus */ static const short SpaceBonusB[64] = {1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 4, 4, 2, 1, 1, 1, 1, 2, 4, 4, 2, 1, 1, 1, 1, 2, 4, 4, 2, 1, 1, 1, 1, 2, 4, 4, 2, 1, 1, 1, 1, 2, 4, 4, 2, 1, 1, 1, 1, 2, 4, 4, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}; #endif #ifdef WHITEAG0 /* Space positional bonus */ static const short SpaceBonusW[64] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5, 5, 5, 5, 0, 0, 0, 0, 3, 4, 4, 3, 0, 0, 0, 0, 2, 4, 4, 2, 0, 0, 0, 0, 1, 4, 4, 1, 0, 0, 0, 0, 1, 4, 4, 1, 0, 0, 0, 0, 1, 2, 2, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}; #elif defined WHITEAG1 /* Space positional bonus */ static const short SpaceBonusW[64] = {1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 7, 7, 3, 1, 1, 1, 1, 3, 6, 6, 3, 1, 1, 1, 1, 3, 5, 5, 3, 1, 1, 1, 1, 2, 4, 4, 2, 1, 1, 1, 1, 2, 3, 3, 2, 1, 1, 1, 1, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}; #elif defined WHITEAG2 /* Space positional bonus */ static const short SpaceBonusW[64] = {1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 7, 8, 8, 7, 1, 1, 1, 1, 6, 7, 7, 6, 1, 1, 1, 1, 5, 6, 6, 5, 1, 1, 1, 1, 4, 4, 4, 4, 1, 1, 1, 1, 3, 3, 3, 3, 1, 1, 1, 1, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}; #elif defined WHITEAG3 /* Space positional bonus */ static const short SpaceBonusW[64] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 8, 8, 7, 7, 0, 0, 0, 0, 7, 7, 5, 5, 0, 0, 0, 0, 6, 6, 4, 4, 0, 0, 0, 0, 4, 4, 4, 3, 0, 0, 0, 0, 3, 3, 3, 3, 0, 0, 0, 0, 2, 2, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}; #elif defined WHITEAG4 /* Space positional bonus */ static const short SpaceBonusW[64] = {1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 4, 4, 2, 1, 1, 1, 1, 2, 4, 4, 2, 1, 1, 1, 1, 2, 4, 4, 2, 1, 1, 1, 1, 2, 4, 4, 2, 1, 1, 1, 1, 2, 4, 4, 2, 1, 1, 1, 1, 2, 4, 4, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}; #endif #endif short Mwpawn[64], Mbpawn[64], Mknight[2][64], Mbishop[2][64]; static short Mking[2][64], Kfield[2][64]; static short c1, c2, *atk1, *atk2, *PC1, *PC2, atak[2][64]; short emtl[2]; static short PawnBonus, BishopBonus, RookBonus; static short KNIGHTPOST, KNIGHTSTRONG, BISHOPSTRONG, KATAK; static short PEDRNK2B, PWEAKH, PADVNCM, PADVNCI, PAWNSHIELD, PDOUBLED, PBLOK; static short RHOPN, RHOPNX, KHOPN, KHOPNX, KSFTY; static short ATAKD, HUNGP, HUNGX, KCASTLD, KMOVD, XRAY, PINVAL; short pscore[2]; short tmtl; /* ............ POSITIONAL EVALUATION ROUTINES ............ */ /* * Inputs are: * pmtl[side] - value of pawns * mtl[side] - value of all material * emtl[side] - vaule of all material - value of pawns - value of king * hung[side] - count of hung pieces * Tscore[ply] - search tree score for ply * ply * Pscore[ply] - positional score for ply ply * INCscore - bonus score or penalty for certain positions * slk - single lone king flag * Sdepth - search goal depth * xwndw - evaluation window about alpha/beta * EWNDW - second evaluation window about alpha/beta * ChkFlag[ply]- checking piece at level ply or 0 if no check */ inline short ScoreKPK (short int side, short int winner, short int loser, short int king1, register short int king2, register short int sq) /* * Score King and Pawns versus King endings. */ { register short s, r; s = ((PieceCnt[winner] == 1) ? 50 : 120); if (winner == white) { r = row (sq) - ((side == loser) ? 1 : 0); if (row (king2) >= r && distance (sq, king2) < 8 - r) s += 10 * row (sq); else s = 500 + 50 * row (sq); if (row (sq) < 6) sq += 16; else if (row (sq) == 6) sq += 8; } else { r = row (sq) + ((side == loser) ? 1 : 0); if (row (king2) <= r && distance (sq, king2) < r + 1) s += 10 * (7 - row (sq)); else s = 500 + 50 * (7 - row (sq)); if (row (sq) > 1) sq -= 16; else if (row (sq) == 1) sq -= 8; } s += 8 * (taxicab (king2, sq) - taxicab (king1, sq)); #if defined(AMIGADB)&&defined(LATTICE) { if (abs(s) >= 10000) flash(),fprintf(stderr, "eval1: s = %d\n", s); return (s); } #else return (s); #endif } inline short ScoreKBNK (short int winner, short int king1, short int king2) /* * Score King+Bishop+Knight versus King endings. This doesn't work all that * well but it's better than nothing. */ { register short s, sq, KBNKsq = 0; for (sq = 0; sq < 64; sq++) if (board[sq] == bishop) KBNKsq = (((row (sq) % 2) == (column (sq) % 2)) ? 0 : 7); s = emtl[winner] - 300; s += ((KBNKsq == 0) ? KBNK[king2] : KBNK[locn (row (king2), 7 - column (king2))]); s -= ((taxicab (king1, king2) + distance (PieceList[winner][1], king2) + distance (PieceList[winner][2], king2))); #if defined(AMIGADB)&&defined(LATTICE) { if (abs(s) >= 10000) flash(),fprintf(stderr, "eval2: s = %d\n", s); return (s); } #else return (s); #endif } inline short int ScoreLoneKing (short int side) /* * Static evaluation when loser has only a king and winner has no pawns or no * pieces. */ { register short winner, loser, king1, king2, s, i; UpdateWeights (); winner = ((mtl[white] > mtl[black]) ? white : black); loser = winner ^ 1; king1 = PieceList[winner][0]; king2 = PieceList[loser][0]; s = 0; if (pmtl[winner] > 0) for (i = 1; i <= PieceCnt[winner]; i++) s += ScoreKPK (side, winner, loser, king1, king2, PieceList[winner][i]); else if (emtl[winner] == valueB + valueN) s = ScoreKBNK (winner, king1, king2); else if (emtl[winner] > valueB) s = 500 + emtl[winner] - DyingKing[king2] - 2 * distance (king1, king2); #if defined(AMIGADB)&&defined(LATTICE) { if (abs((side == winner) ? s : -s) >= 10000) flash(),fprintf(stderr, "eval3: (side == winner) ? s : -s = %d\n", (side == winner) ? s : -s); return ((side == winner) ? s : -s); } #else return ((side == winner) ? s : -s); #endif } short evaluate (register short int side, register short int ply, register short int alpha, register short int beta, short int INCscore, short int *slk, /* output single lone king */ short int *InChk) /* output Check flag */ /* * Compute an estimate of the score by adding the positional score from the * previous ply to the material difference. If this score falls inside a * window which is 180 points wider than the alpha-beta window (or within a * 50 point window during quiescence search) call ScorePosition() to * determine a score, otherwise return the estimated score. If one side has * only a king and the other either has no pawns or no pieces then the * function ScoreLoneKing() is called. */ { register short evflag, xside; short s; xside = side ^ 1; s = -Pscore[ply - 1] + mtl[side] - mtl[xside] - INCscore; hung[white] = hung[black] = 0; *slk = ((mtl[white] == valueK && (pmtl[black] == 0 || emtl[black] == 0)) || (mtl[black] == valueK && (pmtl[white] == 0 || emtl[white] == 0))); if (*slk) evflag = false; else /* should we use the estimete or score the position */ evflag = (ply == 1 || ((ply <= Sdepth)) || ((ply == Sdepth + 1 || ply == (Sdepth + 2)) && (s > (alpha - xwndw) && s < (beta + xwndw))) || (ply > (Sdepth + 2) && s >= (alpha - EWNDW) && s <= (beta + EWNDW))); #ifdef DEBUG4 if (debuglevel & 1) evflag = true; #endif if (evflag) { /* score the position */ ataks (side, atak[side]); if (Anyatak (side, PieceList[xside][0])) return (10001 - ply); ataks (xside, atak[xside]); *InChk = Anyatak (xside, PieceList[side][0]); EvalNodes++; s = ScorePosition (side); } else { /* use the estimate but look at check and slk */ if (SqAtakd (PieceList[xside][0], side)) return (10001 - ply); *InChk = SqAtakd (PieceList[side][0], xside); if (*slk) s = ScoreLoneKing (side); } Pscore[ply] = s - mtl[side] + mtl[xside]; ChkFlag[ply - 1] = ((*InChk) ? Pindex[TOsquare] : 0); #if defined(AMIGADB)&&defined(LATTICE) { if (abs(s) >= 10000) flash(),fprintf(stderr, "eval4: s = %d\n", s); return (s); } #else return (s); #endif } inline void BRscan (short int sq, register short int *s, short int *mob) /* * Find Bishop and Rook mobility, XRAY attacks, and pins. Increment the * hung[] array if a pin is found. */ { register short u, pin; register unsigned char *ppos, *pdir; short piece, *Kf; Kf = Kfield[c1]; *mob = 0; piece = board[sq]; ppos = nextpos[piece][sq]; pdir = nextdir[piece][sq]; u = ppos[sq]; pin = -1; /* start new direction */ do { *s += Kf[u]; if (color[u] == neutral) { (*mob)++; if (ppos[u] == pdir[u]) pin = -1; /* oops new direction */ u = ppos[u]; } else if (pin < 0) { if (board[u] == pawn || board[u] == king) u = pdir[u]; else { if (ppos[u] != pdir[u]) pin = u; /* not on the edge and on to find a pin */ u = ppos[u]; } } else { if (color[u] == c2 && (board[u] > piece || atk2[u] == 0)) { if (color[pin] == c2) { *s += PINVAL; if (atk2[pin] == 0 || atk1[pin] > control[board[pin]] + 1) ++hung[c2]; } else *s += XRAY; } pin = -1; /* new direction */ u = pdir[u]; } } while (u != sq); } inline short int KingScan (register short int sq) /* * Assign penalties if king can be threatened by checks, if squares near the * king are controlled by the enemy (especially the queen), or if there are * no pawns near the king. The following must be true: board[sq] == king c1 * == color[sq] c2 == otherside[c1] */ #define ScoreThreat \ if (color[u] != c2)\ if (atk1[u] == 0 || (atk2[u] & 0xFF) > 1) ++cnt;\ else s -= 3 { register short int s; register short u; register unsigned char *ppos, *pdir; register short cnt, ok; s = 0; cnt = 0; if (HasBishop[c2] || HasQueen[c2]) { ppos = nextpos[bishop][sq]; pdir = nextdir[bishop][sq]; u = ppos[sq]; do { if (atk2[u] & ctlBQ) ScoreThreat; u = ((color[u] == neutral) ? ppos[u] : pdir[u]); } while (u != sq); } if (HasRook[c2] || HasQueen[c2]) { ppos = nextpos[rook][sq]; pdir = nextdir[rook][sq]; u = ppos[sq]; do { if (atk2[u] & ctlRQ) ScoreThreat; u = ((color[u] == neutral) ? ppos[u] : pdir[u]); } while (u != sq); } if (HasKnight[c2]) { pdir = nextdir[knight][sq]; u = pdir[sq]; do { if (atk2[u] & ctlNN) ScoreThreat; u = pdir[u]; } while (u != sq); } s += (KSFTY * KTHRT[cnt]) / 16; cnt = 0; ok = false; pdir = nextpos[king][sq]; u = pdir[sq]; do { if (board[u] == pawn) ok = true; if (atk2[u] > atk1[u]) { ++cnt; if (atk2[u] & ctlQ) if (atk2[u] > ctlQ + 1 && atk1[u] < ctlQ) s -= 4 * KSFTY; } u = pdir[u]; } while (u != sq); if (!ok) s -= KSFTY; if (cnt > 1) s -= (KSFTY); #if defined(AMIGADB)&&defined(LATTICE) { if (abs(s) >= 10000) flash(),fprintf(stderr, "eval5: s = %d\n", s); return (s); } #else return (s); #endif } inline int trapped (register short int sq) /* * See if the attacked piece has unattacked squares to move to. The following * must be true: c1 == color[sq] c2 == otherside[c1] */ { register short u, piece; register unsigned char *ppos, *pdir; piece = board[sq]; ppos = nextpos[ptype[c1][piece]][sq]; pdir = nextdir[ptype[c1][piece]][sq]; if (piece == pawn) { u = ppos[sq]; /* follow no captures thread */ if (color[u] == neutral) { if (atk1[u] >= atk2[u]) return (false); if (atk2[u] < ctlP) { u = ppos[u]; if (color[u] == neutral && atk1[u] >= atk2[u]) return (false); } } u = pdir[sq]; /* follow captures thread */ if (color[u] == c2) return (false); u = pdir[u]; if (color[u] == c2) return (false); } else { u = ppos[sq]; do { if (color[u] != c1) if (atk2[u] == 0 || board[u] >= piece) return (false); u = ((color[u] == neutral) ? ppos[u] : pdir[u]); } while (u != sq); } return (true); } static inline short PawnValue(short int sq, short int side) /* * Calculate the positional value for a pawn on 'sq'. */ { register short j, fyle, rank; register short s, a1, a2, in_square, r, e; a1 = (atk1[sq] & 0x4FFF); a2 = (atk2[sq] & 0x4FFF); rank = row(sq); fyle = column(sq); s = 0; if (c1 == white) { s = Mwpawn[sq]; if ((sq == 11 && color[19] != neutral) || (sq == 12 && color[20] != neutral)) s += PEDRNK2B; if ((fyle == 0 || PC1[fyle - 1] == 0) && (fyle == 7 || PC1[fyle + 1] == 0)) s += ISOLANI[fyle]; else if (PC1[fyle] > 1) s += PDOUBLED; if (a1 < ctlP && atk1[sq + 8] < ctlP) { s += BACKWARD[a2 & 0xFF]; if (PC2[fyle] == 0) s += PWEAKH; if (color[sq + 8] != neutral) s += PBLOK; } if (PC2[fyle] == 0) { if (side == black) r = rank - 1; else r = rank; in_square = (row(bking) >= r && distance(sq, bking) < 8 - r); if (a2 == 0 || side == white) e = 0; else e = 1; for (j = sq + 8; j < 64; j += 8) if (atk2[j] >= ctlP) { e = 2; break; } else if (atk2[j] > 0 || color[j] != neutral) e = 1; if (e == 2) s += (stage * PassedPawn3[rank]) / 10; else if (in_square || e == 1) s += (stage * PassedPawn2[rank]) / 10; else if (emtl[black] > 0) s += (stage * PassedPawn1[rank]) / 10; else s += PassedPawn0[rank]; } } else if (c1 == black) { s = Mbpawn[sq]; if ((sq == 51 && color[43] != neutral) || (sq == 52 && color[44] != neutral)) s += PEDRNK2B; if ((fyle == 0 || PC1[fyle - 1] == 0) && (fyle == 7 || PC1[fyle + 1] == 0)) s += ISOLANI[fyle]; else if (PC1[fyle] > 1) s += PDOUBLED; if (a1 < ctlP && atk1[sq - 8] < ctlP) { s += BACKWARD[a2 & 0xFF]; if (PC2[fyle] == 0) s += PWEAKH; if (color[sq - 8] != neutral) s += PBLOK; } if (PC2[fyle] == 0) { if (side == white) r = rank + 1; else r = rank; in_square = (row(wking) <= r && distance(sq, wking) < r + 1); if (a2 == 0 || side == black) e = 0; else e = 1; for (j = sq - 8; j >= 0; j -= 8) if (atk2[j] >= ctlP) { e = 2; break; } else if (atk2[j] > 0 || color[j] != neutral) e = 1; if (e == 2) s += (stage * PassedPawn3[7 - rank]) / 10; else if (in_square || e == 1) s += (stage * PassedPawn2[7 - rank]) / 10; else if (emtl[white] > 0) s += (stage * PassedPawn1[7 - rank]) / 10; else s += PassedPawn0[7 - rank]; } } if (a2 > 0) { if (a1 == 0 || a2 > ctlP + 1) { s += HUNGP; ++hung[c1]; if (trapped(sq)) ++hung[c1]; } else if (a2 > a1) s += ATAKD; } #if defined(AMIGADB)&&defined(LATTICE) { if (abs(s) >= 10000) flash(),fprintf(stderr, "eval6: s = %d\n", s); return (s); } #else return (s); #endif } inline short KnightValue (short int sq, short int side) /* * Calculate the positional value for a knight on 'sq'. */ { register short s, a2, a1; s = Mknight[c1][sq]; a2 = (atk2[sq] & 0x4FFF); if (a2 > 0) { a1 = (atk1[sq] & 0x4FFF); if (a1 == 0 || a2 > ctlBN + 1) { s += HUNGP; ++hung[c1]; if (trapped (sq)) ++hung[c1]; } else if (a2 >= ctlBN || a1 < ctlP) s += ATAKD; } #if defined(AMIGADB)&&defined(LATTICE) { if (abs(s) >= 10000) flash(),fprintf(stderr, "eval7: s = %d\n", s); return (s); } #else return (s); #endif } inline short BishopValue (short int sq, short int side) /* * Calculate the positional value for a bishop on 'sq'. */ { register short a2, a1; short s, mob; s = Mbishop[c1][sq]; BRscan (sq, &s, &mob); s += BMBLTY[mob]; a2 = (atk2[sq] & 0x4FFF); if (a2 > 0) { a1 = (atk1[sq] & 0x4FFF); if (a1 == 0 || a2 > ctlBN + 1) { s += HUNGP; ++hung[c1]; if (trapped (sq)) ++hung[c1]; } else if (a2 >= ctlBN || a1 < ctlP) s += ATAKD; } #if defined(AMIGADB)&&defined(LATTICE) { if (abs(s) >= 10000) flash(),fprintf(stderr, "eval8: s = %d\n", s); return (s); } #else return (s); #endif } inline short RookValue (register short int sq, short int side) /* * Calculate the positional value for a rook on 'sq'. */ { register short fyle, a2, a1; short s, mob; s = RookBonus; BRscan (sq, &s, &mob); s += RMBLTY[mob]; fyle = column (sq); if (PC1[fyle] == 0) s += RHOPN; if (PC2[fyle] == 0) s += RHOPNX; if (pmtl[c2] > 100 && row (sq) == rank7[c1]) s += 10; if (stage > 2) s += 14 - taxicab (sq, EnemyKing); a2 = (atk2[sq] & 0x4FFF); if (a2 > 0) { a1 = (atk1[sq] & 0x4FFF); if (a1 == 0 || a2 > ctlR + 1) { s += HUNGP; ++hung[c1]; if (trapped (sq)) ++hung[c1]; } else if (a2 >= ctlR || a1 < ctlP) s += ATAKD; } #if defined(AMIGADB)&&defined(LATTICE) { if (abs(s) >= 10000) flash(),fprintf(stderr, "eval9: s = %d\n", s); return (s); } #else return (s); #endif } inline short QueenValue (register short int sq, short int side) /* * Calculate the positional value for a queen on 'sq'. */ { register short s, a2, a1; s = ((distance (sq, EnemyKing) < 3) ? 12 : 0); if (stage > 2) s += 14 - taxicab (sq, EnemyKing); a2 = (atk2[sq] & 0x4FFF); if (a2 > 0) { a1 = (atk1[sq] & 0x4FFF); if (a1 == 0 || a2 > ctlQ + 1) { s += HUNGP; ++hung[c1]; if (trapped (sq)) ++hung[c1]; } else if (a2 >= ctlQ || a1 < ctlP) s += ATAKD; } #if defined(AMIGADB)&&defined(LATTICE) { if (abs(s) >= 10000) flash(),fprintf(stderr, "eval10: s = %d\n", s); return (s); } #else return (s); #endif } inline short KingValue (short int sq, short int side) /* * Calculate the positional value for a king on 'sq'. */ { register short fyle, a2, a1; short s; s = (emtl[side ^ 1] > KINGPOSLIMIT) ? Mking[c1][sq] : Mking[c1][sq] / 2; if (KSFTY > 0) if (Developed[c2] || stage > 0) s += KingScan (sq); if (castld[c1]) s += KCASTLD; else if (Mvboard[kingP[c1]]) s += KMOVD; fyle = column (sq); if (PC1[fyle] == 0) s += KHOPN; if (PC2[fyle] == 0) s += KHOPNX; switch (fyle) { case 5: if (PC1[7] == 0) s += KHOPN; if (PC2[7] == 0) s += KHOPNX; /* Fall through */ case 4: case 6: case 0: if (PC1[fyle + 1] == 0) s += KHOPN; if (PC2[fyle + 1] == 0) s += KHOPNX; break; case 2: if (PC1[0] == 0) s += KHOPN; if (PC2[0] == 0) s += KHOPNX; /* Fall through */ case 3: case 1: case 7: if (PC1[fyle - 1] == 0) s += KHOPN; if (PC2[fyle - 1] == 0) s += KHOPNX; break; default: /* Impossible! */ break; } a2 = (atk2[sq] & 0x4FFF); if (a2 > 0) { a1 = (atk1[sq] & 0x4FFF); if (a1 == 0 || a2 > ctlK + 1) { s += HUNGP; ++hung[c1]; } else s += ATAKD; } #if defined(AMIGADB)&&defined(LATTICE) { if (abs(s) >= 10000) flash(),fprintf(stderr, "eval11: s = %d\n", s); return (s); } #else return (s); #endif } #if !defined NOSCORESPACE inline void ScoreSpace (void) { register short *b, *w, *sw, *sb; register short sBl, sWh; sBl = sWh = 0; for (b = &atak[black][63], w = &atak[white][63], sw = &SpaceBonusW[63], sb = &SpaceBonusB[63]; sw > &SpaceBonusW[0]; b--, w--, sw--, sb--) { if (*b > *w) { if (*b > ctlR) sBl += *sb; } else if (*b < *w) if (*w > ctlR) sWh += *sw; } pscore[white] += (sWh); pscore[black] += (sBl); sscore[white] = sWh; sscore[black] = sBl; } #endif short int ScorePosition (register short int side) /* * Perform normal static evaluation of board position. A score is generated * for each piece and these are summed to get a score for each side. */ { register short int score; register short sq, s, i, xside; UpdateWeights (); xside = side ^ 1; hung[white]= hung[black] = pscore[white] = pscore[black] = 0; #if !defined NOSCORESPACE if (stage < SCORESPLIM) ScoreSpace (); #endif for (c1 = white; c1 <= black; c1++) { c2 = c1 ^ 1; /* atk1 is array of atacks on squares by my side */ atk1 = atak[c1]; /* atk2 is array of atacks on squares by other side */ atk2 = atak[c2]; /* same for PC1 and PC2 */ PC1 = PawnCnt[c1]; PC2 = PawnCnt[c2]; for (i = PieceCnt[c1]; i >= 0; i--) { sq = PieceList[c1][i]; switch (board[sq]) { case pawn: s = PawnValue (sq, side); break; case knight: s = KnightValue (sq, side); break; case bishop: s = BishopValue (sq, side); break; case rook: s = RookValue (sq, side); break; case queen: s = QueenValue (sq, side); break; case king: s = KingValue (sq, side); break; default: s = 0; break; } pscore[c1] += s; svalue[sq] = s; } } if (hung[side] > 1) pscore[side] += HUNGX; if (hung[xside] > 1) pscore[xside] += HUNGX; score = mtl[side] - mtl[xside] + pscore[side] - pscore[xside] + 10; if (dither) { if (flag.hash) srand (starttime + (unsigned int) hashbd); score += urand () % dither; } if (score > 0 && pmtl[side] == 0) if (emtl[side] < valueR) score = 0; else if (score < valueR) score /= 2; if (score < 0 && pmtl[xside] == 0) if (emtl[xside] < valueR) score = 0; else if (-score < valueR) score /= 2; if (mtl[xside] == valueK && emtl[side] > valueB) score += 200; if (mtl[side] == valueK && emtl[xside] > valueB) score -= 200; #if defined(AMIGADB)&&defined(LATTICE) { if (abs(score) >= 10000) flash(),fprintf(stderr, "eval12: score = %d\n", score); return (score); } #else return (score); #endif } static inline void BlendBoard (const short int a[64], const short int b[64], short int c[64]) { register int sq, s; s = 10 - stage; for (sq = 0; sq < 64; sq++) c[sq] = ((a[sq] * s) + (b[sq] * stage)) / 10; } static inline void CopyBoard (const short int a[64], short int b[64]) { register short *sqa, *sqb; for (sqa = a, sqb = b; sqa < a + 64;) *sqb++ = *sqa++; } void ExaminePosition (void) /* * This is done one time before the search is started. Set up arrays Mwpawn, * Mbpawn, Mknight, Mbishop, Mking which are used in the SqValue() function * to determine the positional value of each piece. */ { register short i, sq; short wpadv, bpadv, wstrong, bstrong, z, side, pp, j, k, val, Pd, fyle, rank; static short PawnStorm = false; ataks (white, atak[white]); ataks (black, atak[black]); UpdateWeights (); HasKnight[white] = HasKnight[black] = 0; HasBishop[white] = HasBishop[black] = 0; HasRook[white] = HasRook[black] = 0; HasQueen[white] = HasQueen[black] = 0; for (side = white; side <= black; side++) for (i = PieceCnt[side]; i >= 0; i--) switch (board[PieceList[side][i]]) { case knight: ++HasKnight[side]; break; case bishop: ++HasBishop[side]; break; case rook: ++HasRook[side]; break; case queen: ++HasQueen[side]; break; } if (!Developed[white]) Developed[white] = (board[1] != knight && board[2] != bishop && board[5] != bishop && board[6] != knight); if (!Developed[black]) Developed[black] = (board[57] != knight && board[58] != bishop && board[61] != bishop && board[62] != knight); if (!PawnStorm && stage < 5) PawnStorm = ((column (wking) < 3 && column (bking) > 4) || (column (wking) > 4 && column (bking) < 3)); CopyBoard (pknight, Mknight[white]); CopyBoard (pknight, Mknight[black]); CopyBoard (pbishop, Mbishop[white]); CopyBoard (pbishop, Mbishop[black]); BlendBoard (KingOpening, KingEnding, Mking[white]); BlendBoard (KingOpening, KingEnding, Mking[black]); for (sq = 0; sq < 64; sq++) { fyle = column (sq); rank = row (sq); wstrong = bstrong = true; for (i = sq; i < 64; i += 8) if (Patak (black, i)) { wstrong = false; break; } for (i = sq; i >= 0; i -= 8) if (Patak (white, i)) { bstrong = false; break; } wpadv = bpadv = PADVNCM; if ((fyle == 0 || PawnCnt[white][fyle - 1] == 0) && (fyle == 7 || PawnCnt[white][fyle + 1] == 0)) wpadv = PADVNCI; if ((fyle == 0 || PawnCnt[black][fyle - 1] == 0) && (fyle == 7 || PawnCnt[black][fyle + 1] == 0)) bpadv = PADVNCI; Mwpawn[sq] = (wpadv * PawnAdvance[sq]) / 10; Mbpawn[sq] = (bpadv * PawnAdvance[63 - sq]) / 10; Mwpawn[sq] += PawnBonus; Mbpawn[sq] += PawnBonus; if (Mvboard[kingP[white]]) { if ((fyle < 3 || fyle > 4) && distance (sq, wking) < 3) Mwpawn[sq] += PAWNSHIELD; } else if (rank < 3 && (fyle < 2 || fyle > 5)) Mwpawn[sq] += PAWNSHIELD / 2; if (Mvboard[kingP[black]]) { if ((fyle < 3 || fyle > 4) && distance (sq, bking) < 3) Mbpawn[sq] += PAWNSHIELD; } else if (rank > 4 && (fyle < 2 || fyle > 5)) Mbpawn[sq] += PAWNSHIELD / 2; if (PawnStorm) { if ((column (wking) < 4 && fyle > 4) || (column (wking) > 3 && fyle < 3)) Mwpawn[sq] += 3 * rank - 21; if ((column (bking) < 4 && fyle > 4) || (column (bking) > 3 && fyle < 3)) Mbpawn[sq] -= 3 * rank; } Mknight[white][sq] += 5 - distance (sq, bking); Mknight[white][sq] += 5 - distance (sq, wking); Mknight[black][sq] += 5 - distance (sq, wking); Mknight[black][sq] += 5 - distance (sq, bking); Mbishop[white][sq] += BishopBonus; Mbishop[black][sq] += BishopBonus; for (i = PieceCnt[black]; i >= 0; i--) if (distance (sq, PieceList[black][i]) < 3) Mknight[white][sq] += KNIGHTPOST; for (i = PieceCnt[white]; i >= 0; i--) if (distance (sq, PieceList[white][i]) < 3) Mknight[black][sq] += KNIGHTPOST; if (wstrong) Mknight[white][sq] += KNIGHTSTRONG; if (bstrong) Mknight[black][sq] += KNIGHTSTRONG; if (wstrong) Mbishop[white][sq] += BISHOPSTRONG; if (bstrong) Mbishop[black][sq] += BISHOPSTRONG; if (HasBishop[white] == 2) Mbishop[white][sq] += 8; if (HasBishop[black] == 2) Mbishop[black][sq] += 8; if (HasKnight[white] == 2) Mknight[white][sq] += 5; if (HasKnight[black] == 2) Mknight[black][sq] += 5; Kfield[white][sq] = Kfield[black][sq] = 0; if (distance (sq, wking) == 1) Kfield[black][sq] = KATAK; if (distance (sq, bking) == 1) Kfield[white][sq] = KATAK; Pd = 0; for (k = 0; k <= PieceCnt[white]; k++) { i = PieceList[white][k]; if (board[i] == pawn) { pp = true; z = i + ((row (i) == 6) ? 8 : 16); for (j = i + 8; j < 64; j += 8) if (Patak (black, j) || board[j] == pawn) { pp = false; break; } Pd += ((pp) ? 5 * taxicab (sq, z) : taxicab (sq, z)); } } for (k = 0; k <= PieceCnt[black]; k++) { i = PieceList[black][k]; if (board[i] == pawn) { pp = true; z = i - ((row (i) == 1) ? 8 : 16); for (j = i - 8; j >= 0; j -= 8) if (Patak (white, j) || board[j] == pawn) { pp = false; break; } Pd += ((pp) ? 5 * taxicab (sq, z) : taxicab (sq, z)); } } if (Pd != 0) { val = (Pd * stage2) / 10; Mking[white][sq] -= val; Mking[black][sq] -= val; } } } void UpdateWeights (void) /* * If material balance has changed, determine the values for the positional * evaluation terms. */ { register short s1; emtl[white] = mtl[white] - pmtl[white] - valueK; emtl[black] = mtl[black] - pmtl[black] - valueK; tmtl = emtl[white] + emtl[black]; s1 = ((tmtl > 6600) ? 0 : ((tmtl < 1400) ? 10 : (6600 - tmtl) / 520)); if (s1 != stage) { stage = s1; stage2 = ((tmtl > 3600) ? 0 : ((tmtl < 1400) ? 10 : (3600 - tmtl) / 220)); PEDRNK2B = -15; /* centre pawn on 2nd rank & blocked */ PBLOK = -4; /* blocked backward pawn */ PDOUBLED = -14; /* doubled pawn */ PWEAKH = -4; /* weak pawn on half open file */ PAWNSHIELD = 10 - stage; /* pawn near friendly king */ PADVNCM = 10; /* advanced pawn multiplier */ PADVNCI = 7; /* muliplier for isolated pawn */ PawnBonus = stage; KNIGHTPOST = (stage + 2) / 3; /* knight near enemy pieces */ KNIGHTSTRONG = (stage + 6) / 2; /* occupies pawn hole */ BISHOPSTRONG = (stage + 6) / 2; /* occupies pawn hole */ BishopBonus = BBONUS * stage; RHOPN = 10; /* rook on half open file */ RHOPNX = 4; RookBonus = RBONUS * stage; XRAY = 8; /* Xray attack on piece */ PINVAL = 10; /* Pin */ KHOPN = (3 * stage - 30) / 2; /* king on half open file */ KHOPNX = KHOPN / 2; KCASTLD = 10 - stage; KMOVD = -40 / (stage + 1);/* king moved before castling */ KATAK = (10 - stage) / 2; /* B,R attacks near enemy king */ KSFTY = ((stage < 8) ? KINGSAFETY - 2 * stage : 0); ATAKD = -6; /* defender > attacker */ HUNGP = -12; /* each hung piece */ HUNGX = -18; /* extra for >1 hung piece */ } }