It's effectively a prop bet. If you're a world class table tennis champion and you bet someone you can beat them at table tennis on the proviso that they get to

It's effectively a prop bet. If you're a world class table tennis champion and you bet someone you can beat them at table tennis on the proviso that they get to pick the bats, you can't really complain if you find out later that they have spent six months practicing with frying pans. You just have to pay up. If you don't see the loophole before you agree, you pay. Actually there's a great little bit about this in the movie Guys And Dolls (1955), and what to do if someone bets you that he can make a jack of spades squirt cider in your ear.