The game started way back in "olden times" when we actually had an off-season. The bar was hot and we were bored so oftentimes my friends and I used to just drag stools right out onto the sidewalk and sit there. One of the regulars was a rabid Larry Bird fan and he used to drive us crazy jumping and weaving, yelling "top of the key" and trying to get quarters in the fishes mouth. So to slow him down we had him stand backwards with his toes of the edge of the sidewalk and make him throw it like that, which considerably slowed him down. And the rest, as they say, is history.
It always makes me smile to see groups of people that started so long ago out of simple boredom...and maybe a little alcohol. So next time you're down here give it a try, yelling "Top of the key" is entirely optional.