Defensive move

A defensive move is the only move that holds, found while under attack. Half of tactics is seeing what the opponent threatens, and the puzzle where you have to find the defence is the one players fail most, because the eye looks for its own threats first. The defence that matters is rarely passive: it blocks WITH a threat, it steps out of a fork onto a square that attacks something, it gives back a little to keep a lot.

What makes it work is tempo. A block that attacks the checking piece, or a retreat that hits something, gives the attacker no time to finish the idea. So when attacked, first list everything that answers the threat, then pick the answer that also does something. A pure retreat is the last option, not the first.

To find it, name the threat exactly: which piece, which square, and what happens after. Then the candidates, always the same five: capture the attacker, block, move away, defend, counter-attack something bigger. Most positions offer two or three; the one that holds is the one after which the opponent's next move is not a threat.

At higher level the defence is played before the threat exists: the quiet king move that takes a square away, the pawn move that closes a diagonal, the piece kept on a square it could leave. And the defence includes the sacrifice: an exchange to remove the attacking bishop, a pawn to open a file for the defending rook. The question never changes: after my move, what does the opponent threaten?