Errare Humanum Est
Errors, including horrible howlers, are fairly common in chess. There are numerous discussions of errors in chess, and how to avoid them, in the practical chess literature. Automatisms are important in chess, since they allow one to make decisions rapidly. It could be argued that at least some of the errors that N. Krogius imputed to chess images are in fact attentional errors. The opponent's behaviour is an important emotional factor that might cause distraction and irritation. Mistakes due to insufficient knowledge also occasionally occur at the top level. Many errors are caused by a lack of knowledge. During time trouble, short-term tactics dominate over long-term strategies, intuition comes before look-ahead search and concrete ideas take precedence over abstract considerations. An obvious one is tiredness; after a long and difficult game, or after several days or weeks of playing in a tournament, one is bound to become tired.