Fundamental Tactic
The Zwischenzug
Also known as: In-Between Move, Intermezzo
A zwischenzug is an in-between move: something forcing, inserted before the reply everyone expects. Most often it comes before a recapture. Rather than taking back the instant a piece is captured, you first play a check or a threat the opponent cannot ignore. Because he must answer it, the capture you postponed is still sitting there when you return to it, and the in-between move is pure profit.
1. Bxb5+ Kf8 2. bxc3
What an In-Between Move Is
When an opponent captures something, the reflex is to capture back immediately. A zwischenzug is a move slipped in ahead of that reply. Instead of restoring the material balance at once, you play something your opponent cannot ignore, usually a check but sometimes a threat bigger than the one already on the board. Only after it has been dealt with do you make the recapture you were always going to make.
The idea works because of timing. A capture waiting on the board does not evaporate. The piece you intend to take generally cannot run away while its owner is busy answering a check, since a check swallows his entire move. So the in-between move costs you nothing: you collect it first, and the recapture is still there for you a move later. The whole trick is refusing to move on autopilot.
The Line
Black's bishop has landed on c3, where White's b2-pawn can take it, and bxc3 looks automatic. It is not even bad: after bxc3 Bxc4 dxc4 the dust settles and material is dead level. But that is exactly what Black is counting on. His loose bishop on b5 is eyeing White's bishop on c4, and while White is busy taking back, Black collects it and everything evens out.
White plays Bxb5+ instead. The bishop on b5 is undefended, and taking it arrives with check along the b5-c6-d7-e8 diagonal. Black has nothing that can reach c6 or d7 to block, and nothing that attacks b5, so the king must step aside with Kf8. Only now comes bxc3. The bishop on c3 sat there helplessly the whole time, because answering the check left Black no move to spare for it. White ends a clean bishop ahead.
Finding One
The habit worth building is a pause. Before every recapture, ask one question: is there a check or a serious threat I could play first? Checks are the natural candidates, because the answer is forced and forced answers buy you a free move. Loose enemy pieces are the natural targets. When a capture happens to come with check, as Bxb5 does here, look at it before you look at anything else.
Then test the one condition that matters: will the recapture still be available when you come back to it? If the piece you meant to take can simply walk away during your in-between move, the whole idea collapses. Here it cannot. Without the check, Black would answer with Bd4 or Bf6, or take the b2-pawn, and the bishop escapes. Watch for the same trick from the other side, too. Assuming your opponent has to recapture is a reliable way to lose material.
Key ideas
- A zwischenzug is a forcing move inserted before the expected reply, usually before a recapture.
- The in-between move must be forcing, so a check is the classic choice.
- Here bxc3 at once allows Bxc4 and dead equality; Bxb5+ first wins a whole bishop.
- Answering the check costs Black his move, so the bishop on c3 cannot escape and bxc3 still works.
- Before any recapture, pause and ask whether a check or a bigger threat comes first.