Trading a bishop for a knight based on structural requirements.
Why it matters
Trading a bishop for a knight is a decision, not an accident. It is usually made for one of three reasons: to damage the pawns, to win a square, or to get rid of a bishop that was never going to work.
The move that most often does it — taking a knight on c6 or c3 — hands the opponent doubled pawns and the bishop pair at the same time. Whether that is good depends on whether the position stays closed, which is exactly the judgement worth practising.
See it on a board
The bishop takes the knight and leaves Black with doubled c-pawns and a half-open b-file for White. In return Black has two bishops and will want the position opened.
Checked: the position really has the feature described.
How to play it
- Decide what the trade buys: structure, a square, or removing a bad piece.
- Check whether the position is likely to open. If it is, the bishop pair you gave up will matter more than the pawns you damaged.
- If you take the structure, follow it up: attack the doubled pawn, or occupy the square it can no longer cover.
At each level
The same idea, said the way it is taught at each age.
Rook · ages 6–9
Taking a knight with a bishop is worth it when it wrecks pawns or wins a square you can use. Doing it for no reason gives away the bishop pair.
Queen · ages 8–11
The follow-up decides it. Damaged pawns you never attack are not a weakness, they are just a shape, and the bishops you conceded are permanent.
What goes wrong
- Taking on c6 or c3 out of habit, in a position that is about to open up.
- Doubling the opponent's pawns and then allowing the break that undoubles them for free.
Questions people ask
- Is a bishop always worth more than a knight?
- On average, slightly. In a specific position it depends on the pawns: a knight with an outpost in a closed position is worth more than a bishop with nothing to bite on.