Zwischenzugs are among the most commonly missed tactics because they disrupt the expected flow of a sequence. In a typical exchange of pieces, players often assume the recapture is automatic, but a strong intermediate move can change the evaluation of the entire combination.
The most effective zwischenzugs involve checks, since check forces the opponent to respond immediately. For example, after capturing a piece, instead of recapturing, a player might first give check with another piece, forcing the opponent's king to move, and only then complete the recapture. This can gain tempo, improve piece placement, or win additional material.
Always ask yourself before making an "automatic" recapture: is there a stronger intermediate move? This habit catches many opponents off guard and is essential for accurate tactical calculation. Zwischenzugs are a key reason why chess combinations often go deeper than they initially appear.