def defencive_moves_tactic(model, ply, phase):
# ------------------------------------------------------------------------ #
# Test if we threat something, or at least put more pressure on it #
# ------------------------------------------------------------------------ #
# We set bishop value down to knight value, as it is what most people expect
bishopBackup = PIECE_VALUES[BISHOP]
PIECE_VALUES[BISHOP] = PIECE_VALUES[KNIGHT]
board = model.getBoardAtPly(ply).board
oldboard = model.getBoardAtPly(ply - 1).board
move = model.getMoveAtPly(ply - 1).move
fcord = FCORD(move)
tcord = TCORD(move)
found_threatens = []
found_increases = []
# What do we attack now?
board.setColor(1 - board.color)
for ncap in genCaptures(board):
# getCaptures also generate promotions
if FLAG(ncap) in PROMOTIONS:
continue
# We are only interested in the attacks of the piece we just moved
if FCORD(ncap) != TCORD(move):
continue
# We don't want to move back
if TCORD(ncap) == FCORD(move):
continue
# We don't thread the king. We check him! (in another function)
if board.arBoard[TCORD(ncap)] == KING:
continue
# If we also was able to attack that cord last time, we don't care
if validateMove(oldboard, newMove(FCORD(move), TCORD(ncap))):
continue
# Test if we threats our enemy, at least more than before
see0 = staticExchangeEvaluate(oldboard, TCORD(ncap),
1 - oldboard.color)
see1 = staticExchangeEvaluate(board, TCORD(ncap), 1 - oldboard.color)
if see1 > see0:
# If a new winning capture has been created
if see1 > 0:
# Find the easiest attack
attacks = getAttacks(board, TCORD(ncap), board.color)
v, cord = min((PIECE_VALUES[board.arBoard[fc]], fc)
for fc in iterBits(attacks))
easiestAttack = newMove(cord, TCORD(ncap))
found_threatens.append(toSAN(board, easiestAttack, True))
# Even though we might not yet be strong enough, we might still
# have strengthened another friendly attack
else:
found_increases.append(reprCord[TCORD(ncap)])
board.setColor(1 - board.color)
# -------------------------------------------------------------------- #
# Test if we defend a one of our pieces #
# -------------------------------------------------------------------- #
found_defends = []
# Test which pieces were under attack
used = []
for ncap in genCaptures(board):
# getCaptures also generate promotions
if FLAG(ncap) in PROMOTIONS:
continue
# We don't want to know about the same cord more than once
if TCORD(ncap) in used:
continue
used.append(TCORD(ncap))
# If the attack was poining on the piece we just moved, we ignore it
if TCORD(ncap) == FCORD(move) or TCORD(ncap) == TCORD(move):
continue
# If we were already defending the piece, we don't send a new
# message
if defends(oldboard, FCORD(move), TCORD(ncap)):
continue
# If the attack was not strong, we ignore it
see = staticExchangeEvaluate(oldboard, ncap)
if see < 0:
continue
v = defends(board, TCORD(move), TCORD(ncap))
# If the defend didn't help, it doesn't matter. Like defending a
# bishop, threatened by a pawn, with a queen.
# But on the other hand - it might still be a defend...
# newsee = staticExchangeEvaluate(board, ncap)
# if newsee <= see: continue
if v:
found_defends.append(reprCord[TCORD(ncap)])
# ------------------------------------------------------------------------ #
# Test if we are rescuing an otherwise exposed piece #
# ------------------------------------------------------------------------ #
# Rescuing is only an option, if our own move wasn't an attack
if oldboard.arBoard[tcord] == EMPTY:
see0 = staticExchangeEvaluate(oldboard, fcord, oldboard.color)
see1 = staticExchangeEvaluate(board, tcord, oldboard.color)
if see1 > see0 and see1 > 0:
yield _("rescues a %s") % reprPiece[board.arBoard[tcord]].lower()
if found_threatens:
yield _("threatens to win material by %s") % join(found_threatens)
if found_increases:
yield _("increases the pressure on %s") % join(found_increases)
if found_defends:
yield _("defends %s") % join(found_defends)
PIECE_VALUES[BISHOP] = bishopBackup
def defencive_moves_tactic(model, ply, phase):
# ------------------------------------------------------------------------ #
# Test if we threat something, or at least put more pressure on it #
# ------------------------------------------------------------------------ #
# We set bishop value down to knight value, as it is what most people expect
bishopBackup = PIECE_VALUES[BISHOP]
PIECE_VALUES[BISHOP] = PIECE_VALUES[KNIGHT]
board = model.getBoardAtPly(ply).board
oldboard = model.getBoardAtPly(ply - 1).board
move = model.getMoveAtPly(ply - 1).move
fcord = FCORD(move)
tcord = TCORD(move)
found_threatens = []
found_increases = []
# What do we attack now?
board.setColor(1 - board.color)
for ncap in genCaptures(board):
# getCaptures also generate promotions
if FLAG(ncap) in PROMOTIONS:
continue
# We are only interested in the attacks of the piece we just moved
if FCORD(ncap) != TCORD(move):
continue
# We don't want to move back
if TCORD(ncap) == FCORD(move):
continue
# We don't thread the king. We check him! (in another function)
if board.arBoard[TCORD(ncap)] == KING:
continue
# If we also was able to attack that cord last time, we don't care
if validateMove(oldboard, newMove(FCORD(move), TCORD(ncap))):
continue
# Test if we threats our enemy, at least more than before
see0 = staticExchangeEvaluate(oldboard, TCORD(ncap),
1 - oldboard.color)
see1 = staticExchangeEvaluate(board, TCORD(ncap), 1 - oldboard.color)
if see1 > see0:
# If a new winning capture has been created
if see1 > 0:
# Find the easiest attack
attacks = getAttacks(board, TCORD(ncap), board.color)
v, cord = min((PIECE_VALUES[board.arBoard[fc]], fc)
for fc in iterBits(attacks))
easiestAttack = newMove(cord, TCORD(ncap))
found_threatens.append(toSAN(board, easiestAttack, True))
# Even though we might not yet be strong enough, we might still
# have strengthened another friendly attack
else:
found_increases.append(reprCord[TCORD(ncap)])
board.setColor(1 - board.color)
# -------------------------------------------------------------------- #
# Test if we defend a one of our pieces #
# -------------------------------------------------------------------- #
found_defends = []
# Test which pieces were under attack
used = []
for ncap in genCaptures(board):
# getCaptures also generate promotions
if FLAG(ncap) in PROMOTIONS:
continue
# We don't want to know about the same cord more than once
if TCORD(ncap) in used:
continue
used.append(TCORD(ncap))
# If the attack was poining on the piece we just moved, we ignore it
if TCORD(ncap) == FCORD(move) or TCORD(ncap) == TCORD(move):
continue
# If we were already defending the piece, we don't send a new
# message
if defends(oldboard, FCORD(move), TCORD(ncap)):
continue
# If the attack was not strong, we ignore it
see = staticExchangeEvaluate(oldboard, ncap)
if see < 0:
continue
v = defends(board, TCORD(move), TCORD(ncap))
# If the defend didn't help, it doesn't matter. Like defending a
# bishop, threatened by a pawn, with a queen.
# But on the other hand - it might still be a defend...
# newsee = staticExchangeEvaluate(board, ncap)
# if newsee <= see: continue
if v:
found_defends.append(reprCord[TCORD(ncap)])
# ------------------------------------------------------------------------ #
# Test if we are rescuing an otherwise exposed piece #
# ------------------------------------------------------------------------ #
# Rescuing is only an option, if our own move wasn't an attack
if oldboard.arBoard[tcord] == EMPTY:
see0 = staticExchangeEvaluate(oldboard, fcord, oldboard.color)
see1 = staticExchangeEvaluate(board, tcord, oldboard.color)
if see1 > see0 and see1 > 0:
yield _("rescues a %s") % reprPiece[board.arBoard[tcord]].lower()
if found_threatens:
yield _("threatens to win material by %s") % join(found_threatens)
if found_increases:
yield _("increases the pressure on %s") % join(found_increases)
if found_defends:
yield _("defends %s") % join(found_defends)
PIECE_VALUES[BISHOP] = bishopBackup