def test_move_value_black(self):
'''
Test move_value function playing with black pieces
'''
board = chess.Board(
'rnbqkbnr/ppp1pppp/8/3p4/4P3/8/PPPP1PPP/RNBQKBNR b KQkq - 0 1')
move = chess.Move.from_uci('d5e4')
# pawn takes pawn
pawn_for_pawn = move_value(board, move, check_end_game(board))
self.assertEqual(pawn_for_pawn, 5,
f'Pawn for pawn {pawn_for_pawn} but it should be 5')
board = chess.Board(
'rnb1kbnr/ppp1pppp/8/3p1q2/4P3/3P1P2/PPP1B1PP/RNBQK1NR b KQkq - 0 1')
move = chess.Move.from_uci('f5e4')
# queen takes pawn
queen_for_pawn = move_value(board, move, check_end_game(board))
self.assertEqual(
queen_for_pawn, 800, f'Queen for pawn {queen_for_pawn} but it should be 800')
board = chess.Board(
'rnbqkbnr/ppp1pppp/8/3p4/2Q1P3/3P1P2/PPP1B1PP/RNB1K1NR b KQkq - 0 1')
move = chess.Move.from_uci('d5c4')
# pawn takes queen
pawn_for_queen = move_value(board, move, check_end_game(board))
self.assertEqual(
pawn_for_queen, -775, f'Pawn for queen {pawn_for_queen} but it should be -775')
best_to_worst = list(
sorted([pawn_for_queen, pawn_for_pawn, queen_for_pawn]))
self.assertEqual(
best_to_worst, [pawn_for_queen, pawn_for_pawn, queen_for_pawn])
def test_move_value_white(self):
"""
Test move_value function playing with white pieces
"""
board = chess.Board(
"rnbqkbnr/ppp1pppp/8/3p4/4P3/8/PPPP1PPP/RNBQKBNR w KQkq - 0 1")
move = chess.Move.from_uci("e4d5")
# pawn takes pawn
pawn_for_pawn = move_value(board, move, check_end_game(board))
self.assertEqual(pawn_for_pawn, 5,
f"Pawn for pawn {pawn_for_pawn} but it should be 5")
board = chess.Board(
"rnbqkbnr/ppp1pppp/8/3p4/2Q1P3/3P1P2/PPP1B1PP/RNB1K1NR w KQkq - 0 1"
)
move = chess.Move.from_uci("c4d5")
# queen takes pawn
queen_for_pawn = move_value(board, move, check_end_game(board))
self.assertEqual(
queen_for_pawn,
-800,
f"Queen for pawn {queen_for_pawn} but it should be -800",
)
board = chess.Board(
"rnb1kbnr/ppp1pppp/8/3p1q2/4P3/3P1P2/PPP1B1PP/RNBQK1NR w KQkq - 0 1"
)
move = chess.Move.from_uci("e4f5")
# pawn takes queen
pawn_for_queen = move_value(board, move, check_end_game(board))
self.assertEqual(
pawn_for_queen, 790,
f"Pawn for Queen {pawn_for_queen} but it should be 790")
board = chess.Board("8/4P3/2k5/8/8/3K4/8/8 w - - 0 1")
move = chess.Move.from_uci("e7e8q")
# pawn promotes
pawn_promotes = move_value(board, move, check_end_game(board))
self.assertEqual(
pawn_promotes,
float("inf"),
f"Pawn promotes was {pawn_promotes} but it should be inf",
)
worst_to_best = list(
sorted(
[pawn_promotes, pawn_for_queen, pawn_for_pawn,
queen_for_pawn]))
self.assertEqual(
worst_to_best,
[queen_for_pawn, pawn_for_pawn, pawn_for_queen, pawn_promotes],
)
def test_end_game(self):
# starting fen
board = chess.Board(
"rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1")
self.assertEqual(check_end_game(board), False)
# no queens
board = chess.Board(
"rnb1kbnr/ppp1pppp/8/8/8/8/PPP1PPPP/RNB1KBNR w KQkq - 0 1")
self.assertEqual(check_end_game(board), True)
# one queen and one minor piece each
board = chess.Board("3k3q/3p4/8/8/8/8/4P3/Q3K3 w - - 0 1")
self.assertEqual(check_end_game(board), True)
def test_move_value_black(self):
"""
Test move_value function playing with black pieces
"""
board = chess.Board(
"rnbqkbnr/ppp1pppp/8/3p4/4P3/8/PPPP1PPP/RNBQKBNR b KQkq - 0 1")
move = chess.Move.from_uci("d5e4")
# pawn takes pawn
pawn_for_pawn = move_value(board, move, check_end_game(board))
self.assertEqual(pawn_for_pawn, -5,
f"Pawn for pawn {pawn_for_pawn} but it should be -5")
board = chess.Board(
"rnb1kbnr/ppp1pppp/8/3p1q2/4P3/3P1P2/PPP1B1PP/RNBQK1NR b KQkq - 0 1"
)
move = chess.Move.from_uci("f5e4")
# queen takes pawn
queen_for_pawn = move_value(board, move, check_end_game(board))
self.assertEqual(
queen_for_pawn, 800,
f"Queen for pawn {queen_for_pawn} but it should be 800")
board = chess.Board(
"rnbqkbnr/ppp1pppp/8/3p4/2Q1P3/3P1P2/PPP1B1PP/RNB1K1NR b KQkq - 0 1"
)
move = chess.Move.from_uci("d5c4")
# pawn takes queen
pawn_for_queen = move_value(board, move, check_end_game(board))
self.assertEqual(
pawn_for_queen,
-790,
f"Pawn for queen {pawn_for_queen} but it should be -790",
)
best_to_worst = list(
sorted([pawn_for_queen, pawn_for_pawn, queen_for_pawn]))
self.assertEqual(best_to_worst,
[pawn_for_queen, pawn_for_pawn, queen_for_pawn])
def test_move_value_white(self):
'''
Test move_value function playing with white pieces
'''
board = chess.Board(
'rnbqkbnr/ppp1pppp/8/3p4/4P3/8/PPPP1PPP/RNBQKBNR w KQkq - 0 1')
move = chess.Move.from_uci('e4d5')
# pawn takes pawn
pawn_for_pawn = move_value(board, move, check_end_game(board))
board = chess.Board(
'rnbqkbnr/ppp1pppp/8/3p4/2Q1P3/3P1P2/PPP1B1PP/RNB1K1NR w KQkq - 0 1')
move = chess.Move.from_uci('c4d5')
# queen takes pawn
queen_for_pawn = move_value(board, move, check_end_game(board))
self.assertEqual(
queen_for_pawn, -800, f'Queen for pawn {queen_for_pawn} but it should be -800')
board = chess.Board(
'rnb1kbnr/ppp1pppp/8/3p1q2/4P3/3P1P2/PPP1B1PP/RNBQK1NR w KQkq - 0 1')
move = chess.Move.from_uci('e4f5')
# pawn takes queen
pawn_for_queen = move_value(board, move, check_end_game(board))
self.assertEqual(
pawn_for_queen, 775, f'Pawn for Queen {pawn_for_queen} but it should be 775')
board = chess.Board(
'8/4P3/2k5/8/8/3K4/8/8 w - - 0 1')
move = chess.Move.from_uci('e7e8q')
# pawn promotes
pawn_promotes = move_value(board, move, check_end_game(board))
self.assertEqual(pawn_promotes, float(
'inf'), f'Pawn promotes was {pawn_promotes} but it should be inf')
worst_to_best = list(
sorted([pawn_promotes, pawn_for_queen, pawn_for_pawn, queen_for_pawn]))
self.assertEqual(
worst_to_best, [queen_for_pawn, pawn_for_pawn, pawn_for_queen, pawn_promotes])
def get_ordered_moves(board: chess.Board) -> List[chess.Move]:
'''
Get legal moves.
Attempt to sort moves by best to worst.
Use piece values (and positional gains/losses) to weight captures.
'''
end_game = check_end_game(board)
def orderer(move):
return move_value(board, move, end_game)
in_order = sorted(board.legal_moves, key=orderer,
reverse=(board.turn == chess.WHITE))
return list(in_order)