(paraphrasing) "My daddy told me 'never trust a man who tries to bet you that he can make a card jump out of a sealed pack of cards and squirt cider in your ear, for if you do, sure as I'm your daddy, you'll end up with an earful of cider.'"
I've covered men's eyes (doesn't work on women) and asked them to bet on the color of tie they were wearing. No takers.