Alien Ball
ShortStory 6,459 words Recommended by 2 award/anthology sources
"They have three arms, one of which, when they play against us, they tie behind their backs. They’re short and squat and look more like the basketball writ large than any kind of basketball player. They can’t dunk or even run very well. But when they play against each other, they transform the game into something else."
Quasar links out; the story lives on Asimov's, where the author gets the click.