Chess
When he was young Christian Bär played activley chess in the Schachklub Kaiserslautern 1905. Later chess turned out not to be a good counterbalance to professional mathematics. Thus chess was soon limited to an occasional bughouse chess game. In 2010 the opportunity arose to participate in a simultaneous game against the then chess world champion Viswanathan Anand. After 33 moves however, Christian Bär had to resign.