pawn on g4 and it also prevents the advance ...f3+ because it would simply the pawn – then either the other pawn is exchanged for the bishop (an immediate draw) or the pawn advances (an easily drawn position). Otherwise the bishop alternates between the squares d1 and e2. If two pawns are connected, they normally win if they reach their sixth , otherwise the game may be a draw (as above). If two pawns are separated by one they usually draw, but win if they are farther apart. In some cases with more pawns on the board, it is actually advantageous to have the bishops on opposite colors if one side has weak pawns. In the 1925 game Efim Bogoljubov–Max Blümich (see diagram), White wins because of the bishops being on opposite colors making Black weak on the black squares, the weakness of Black's isolated pawns on the , and the weak doubled pawns on the . The game continued: 29.Kd2 Ke7 30.Kc3 f6 31.Kd4 Be6 32.Kc5 Kd7 33.Kb6 g5 34.Kxa6 Kc7 35.Bb6+ Kc8 36.Bc5 Kc7 37.Bf8 f5 38.Bxg7 f4 39.Bf6 f3 40.gxf3 exf3 41.Bxg5 Bxh3 42.Bf4+ Wrong bishop In an endgame with a bishop, in some cases the bishop is the "wrong bishop", meaning that it is on the wrong color of square for some purpose (usually promoting a pawn). For example, with just a bishop and a , if the bishop cannot control the promotion square of the pawn, it is said to be the "wrong bishop" or the pawn is said to be the wrong rook pawn. This results in some positions being drawn (by setting up a fortress) which otherwise would be won. History The bishop's predecessor in medieval chess, shatranj (originally chaturanga), was the alfil, meaning "elephant", which could leap two squares along any diagonal, and could jump over an intervening piece. As a consequence, each fil was restricted to eight squares, and no fil could attack another. The modern bishop first appeared shortly after 1200 in Courier chess. A piece with this move, called a or crocodile, is part of the Grande Acedrex in the compiled in 1283 for King Alfonso X of Castile. The game is attributed to "India", then a very vague term. About half a century later Muḥammad ibn Maḥmud al-Āmulī, in his Treasury of the Sciences, describes an expanded form of chess with two pieces moving "like the rook but