[colomon]

Well, for one thing it uses slang which is probably only vaguely recognizable to the majority of the non-American English-speaking world. And for another thing, it relies on a fact which I (starter on the (American) football team for five years during junior high and high school) didn't know. I mean, it makes sense that the two throwing styles would produce spins in the opposite direction, but I had to stop and think about it.