Ok to do this first,u wanna practice it in practice mode. First get game breaker (duh) then call for a jump-off Dunk and make a defender stick you ( to call for a jump off dunk hit down on the D pad. To make a defender come out hit left. PRACTICE ONLY but the jump off dunk is also in games)now wait until he runs on the right of your jump off dunker then do the jump off dunk and don't let go. And the rest should run perfectly.

after your plan runs perfectly the ball will fall in the net and the game should say


Hometown
Chicago

Ok, when you have gamebreaker make sure you have tim duncan on your team this only works with him for some reason, for all I know at least. Now when defense is sticking you for gamebreaker, do the jump off the back move with tim duncan and hold it and don't let go afterwards you should crash into the rim with his chest and then the ball should roll in and it should say

Homecourt
St. Croix

90% of the time this works, so don't depend on it to win your game, but remember it only works with Time Duncan for now if anyone else you shall post it.