When I was growing up my father had an expression "I'll bet you dollars to donuts...." He'd use that expression to express an opinion, such as, "I'll bet you dollars to donuts that Mickey Mantle will hit a home run today."

The expression reflected his confidence that his opinion was correct, as if to say "I'll give you twenty to one odds on that."

Well my Dad's expression can't be used anymore because I just paid $1 per donut.