An operating theory of chessboxing i have heard is that it's really, really hard to play chess very well at all once you've been punched in the head. As such, chessboxing is essentially boxing, with extended breaks between rounds, during which the contenders happen to play chess.
In the words of David Mitchell (paraphrased) Mike Tyson would be a very good chess boxer given that after the first boxing round, his opponent would be unconscious.
