Overall, this is a pretty easy achievement, and certainly an over priced one for anyone who's gamerscore whoring, but nonetheless - here's how to do it fast:
Adjust the game to the following settings:
Easiest difficulty, no fatigue, manual subs. You can also toy around with foul settings if you want. Then lock positions on the player you have decided to use (I recommend doing this while getting Kobe's 81 against Toronto).
Try to stay around the middle of the court while on defense, in order for really fast break. But really, with any approach, you will get this done. I managed to clear 100 just before half-time.