A guy and his dog went into a bar. The guy tells the bartender, named Rafe, that his dog is the smartest dog in the world. Rafe tells the guy to prove it.

Guy: What's the bartenders name?
Dog: Rafe!

Guy: What's the thing that covers a house?
Dog: Roof!

Guy: What is the opposite of smooth?
Dog: Rough!

Guy: Who's the greatest baseball player of all time?
Dog: Ruth!

Then Rafe kicks the guy and his dog out of the bar because he's had enough of their trickery. When outside the bar, the dog says to the guy, "I think I know what went wrong. I should have said 'Mantle'!"