A bad bishop is blocked by its own pawns on its color; a good bishop has free roam.
Why it matters
A bishop only travels on one colour. If your own pawns are stuck on that colour, the bishop has nowhere to go and nothing to attack — it is a piece in name only.
The fix is rarely to move the bishop. It is to move the pawns, or to trade the bishop for something that works. Recognising which of your bishops is the bad one, early, changes which pawn moves you are willing to make.
See it on a board
Black's bishop on c8 is light-squared and every black pawn that matters sits on a light square. White's bishop, on the other colour, has open diagonals.
Checked: the position really has the feature described.
How to play it
- Look at the colour your bishop moves on, and count your own fixed pawns standing on it.
- If there are many, put future pawns on the other colour, or find a break that frees the bishop.
- If the bishop cannot be freed, trade it — even for a knight, which is normally the worse piece.
At each level
The same idea, said the way it is taught at each age.
Bishop · ages 5–7
Your bishop only uses one colour of square. Try not to put your pawns on that colour, or the bishop has nowhere to go.
Rook · ages 6–9
A bad bishop is only bad while the pawns are fixed. If a break is available, the same bishop can become the best piece on the board in two moves.
What goes wrong
- Blocking your own bishop with pawn moves that look solid.
- Keeping a bad bishop out of pride when a trade for a knight was available.
Questions people ask
- Is a bad bishop always worse than a knight?
- In a fixed position, usually yes. If the pawn structure can still change, the bishop may be worth keeping, because one break can turn it into the better piece.