Chess Blunder Checklist

To help track the reasons why a mistake was made during the game.

Health

1. Not enough sleep
2. Headache, cold, etc.
3. Food problem: hungry, ate too much, too much sugar, etc.

Concentration

1. External distraction (noise, light, etc.)
2. Internal distraction (worried about prior mistake, other issues, etc.)

Lack of familiarity with tactical pattern

1. Visualization – did not correctly retain piece position in analyzed (possible) sequences
2. Board vision – did not see entire (current) board properly and missed a move capability

Thought Process Error

1. Hope Chess – did not attempt to look for opponent’s dangerous replies
2. Analytical error – miscalculation/missed sequence
3. Quiescence error – stopped analyzing too soon
4. Did not look for all the things a move did
5. Did not look for a better move
6. Opponent’s move was forced so did not look for its threats, too

Time Management Error

1. Played too fast
2. Got into unnecessary time trouble
3. Panicked trying to avoid time trouble

Psychology

1. Underestimated opponent
2. Excessive fear of opponent
3. Overconfident in winning (drawn) position

Source: Dan Heisman
http://www.chesscafe.com/heisman/heisman.htm