A blunder is a gross mistake in which a player simply fails to notice a threat: leaves a piece en prise, misses a mate in one or does not see that the opponent can capture. In notation a blunder is marked with two question marks: ??
1. 2. 3.
Why we blunder
- Haste. A player sees a “good” move and plays it without checking what has changed on the board.
- Tunnel vision. Attention is fixed on one part of the board — for example, your own attack — and a threat on the other wing goes unnoticed.
- Fatigue and time trouble. At the end of a long game and when short of time, mistakes multiply.
- Backward moves. Pieces retreating and knight moves “backwards” are harder to notice.
How to get rid of blunders
You can never eliminate them completely: even world champions blunder. But you can make them rare.
- Check before you move. Having decided where to go, mentally put the piece on its new square and ask: “What can my opponent do now? What checks, captures, threats do they have?”
- Look at your opponent's move. Every move they make is a message: what are they planning, what are they attacking?
- Keep your pieces protected. Undefended pieces are the ones most often “hung”.
- Solve puzzles. Tactical vision can be trained: the more patterns you know, the faster you notice threats.
- Do not play when tired. Short games with a fresh head are more useful than a long series of blitz late at night.
If your opponent blunders
Do not rush to take the “gift”. First ask: could it be a trap? Sometimes a “blunder” turns out to be a sacrifice, as in the famous Légal's mate.