Without other pieces besides pawns and the kings, these endings are widely known for their tendency to result in a draw.
With additional pieces, the stronger side has more chances to win, but still not as many as when bishops are on the same color.
Many players in a poor position have escaped a loss by trading down to such an endgame.
Two or even three extra pawns may not suffice for a win either, since the weaker side can create a blockade on the squares on which their bishop operates.
[6] The attacker should generally put his pawns on squares of the opposite color as his bishop to prevent a blockade.
[12] The rule that holds in most cases is that if only one file separates the pawns the game is a draw, otherwise the attacker wins.
Then the attacking king can support the pawn blocked by the bishop and win the piece.
White resigned in this position because he knew a "rule" articulated by Fine in the first edition of Basic Chess Endings: "If the pawns are two or more files apart, they win.
(complete game) Three files separate Black's two pawns, but the players agreed to a draw after 52.Bb1 Kg7 53.Kg2.
Alekhine explained in the tournament book that White "can now sacrifice his Bishop for the [d-pawn], inasmuch as the King has settled himself in the all-important corner".
White cannot make progress: 4. d6+ is met, as always, by 4... Bxd6 5. exd6+ Kxd6 with an immediate draw; 4. e6 gives Black an unbreakable blockade on the dark squares; and White can never prepare for d6+ by playing Kc5 because Black plays ... Bxe5.
A similar position with White's pawns on the sixth rank is a win because the black bishop has no room to move and maintain the attack on the pawn on d6, thus Black is defeated because of zugzwang.
[26] In Berger versus Kotlerman, the pawns are separated by two files, but the game was drawn.
In this game[28] Black has an inferior position, but he draws by exchanging queens and rooks, giving up two pawns, and reaching a drawn endgame: The blockade has been set up.
[31] In an endgame with opposite-colored bishops, positional factors may be more important than material (see quotes below).
Grandmaster Lev Alburt writes, "Black has an extra pawn, but his opponent appears to have a reasonable blockade in place.
If Fischer had won this game, he would have tied with Boris Spassky for first place in the 1966 Piatigorsky Cup tournament.
In this position from a game[44] between Fischer and Lev Polugaevsky a pair of rooks had just been exchanged.
[45] In this 1932 game[46] between Milan Vidmar and Géza Maróczy, White was three pawns ahead, but was unable to win.
As stated above, in endgames with opposite-colored bishops, positional factors may be more important than material differences.
[51] In this 1976 game between Bojan Kurajica and Anatoly Karpov, the material is even but Black has pinned down White's queenside pawns and is preparing to break through.
If both sides have an additional matching piece, the situation is much more complex and cannot be easily codified.
Generally, the presence of the additional pieces gives the stronger side more winning chances.
The most difficult problem encountered by the stronger side is usually in breaking a blockade by the opposite bishop.
[58] This type of endgame was reached in a 2006 game between Veselin Topalov and Levon Aronian, see the first diagram.
White was able to make slow progress (see the second diagram, showing the position after 72 moves).
The stronger side should try to get two widely spaced passed pawns before exchanging queens.
The stronger side must increase his advantage before exchanging queens and sometimes this is done with a direct attack on the king.
[60] The earliest opposite-colored bishop endgame in the ChessBase database is an 1862 game between Louis Paulsen and Adolf Anderssen in their unofficial world championship match.
Play continued: This 1620 game between an unknown player and Gioachino Greco was won by Black on move 50.