I usually would get 12 - 14! 
Very fun!! I loved that when u dunk on the baskets, fireworks would pop out of them!
...You definitely don't have the right game in mind.
Are you thinkin of that game from Mario Party 6? I think it was called Dunk Bros or something.
Yeah, it was Dunk Bros. It's a Rare mini-game that you get for clearing Thirsty Gulch, I believe.
Anyway, if you're on the far left or right, you could really make a beeline for the baskets to prevent your opponents from scoring. When it changes direction, work on other hoops.