Chess boxing, or chessboxing, is a hybrid that combines two traditional pastimes: chess , a cerebral board game, and boxing , a physical sport. The competitors fight in alternating rounds of chess and boxing. Chessboxing was invented by Dutch performance artist Iepe Rubingh .   What was initially only thought to be an art performance quickly turned into a fully developed competitive sport.  Chessboxing is particularly popular in Germany, the United Kingdom, India, and Russia.