NBA 2K9
50 Achievements
1,000
Xbox 360
Rebound Margin +7
Achieved by winning the rebound battle by a margin of +7 with any team.
20
How to unlock the Rebound Margin +7 achievement in NBA 2K9 - Definitive Guide
All I did to get this achievement was play a game on Rookie with 10 minute quarters. I played the Western Conference All-Stars vs. the Oklahoma Thunder. If you are struggling you can change the rebounding sliders as well, but it shouldn't be a problem with Yao on your team.
You should get this easily by playing as an All Star team versus a bad team such as Memphis or Oklahoma. I got this by only playing a 3 minute game. If you are unable to get this on your own feel free to adjust the sliders in your favor.