The idea of a good bishop or “bad bishop” is an endgame strategy for bishops. A good bishop is a bishop that is on the opposite color to its own pawns. This seems illogical, since such a bishop cannot protect its own pawns, but the advantage in the endgame is usually two-fold:
- Mobility: its own pawns do not get in the way of the Bishop, so it is very mobile; and
- Attack: a pawn on the opposite color squares as its pawns is usually on the same color squares as enemy pawns (blocked pawns and interlocking pawn chains are usually on opposite colors). So the “good bishop” can attack the enemy pawns.
Bishop Endings: a “good bishop” against a “bad bishop” is usually a large advantage in Same Color Bishop Endings. These types of endings are fairly easily won by logical play, albeit in a slow and painstaking way.
Exception: Opposite Color Bishop Endings: It is not so much of an advantage to have a “good bishop” in an Opposite Color Bishop Ending. Such endings, which will tend to be drawish even if one bishop is “good” and the other is “bad”.
Bishop-vs-Knight Endings: a “good bishop” against a “bad knight” is not a particularly well-known type of ending (less so than “good knight vs bad bishop”). However, a good bishop in an open position will do well against a Knight.
Good Bishop vs Good Knight. In a closed position with blocked pawn chains, a “good bishop” is basically fighting a “good Knight” in a difficult ending, and it’s not a clear win either way, but my expectation would be for the Knight to win in most such cases.
Related Chess Tactics
Read more about these related chess strategies: