NBA 2K9
50 Achievements
1,000
Xbox 360
15 Threes
Achieved by making 15 three pointers or more with any team.
15
How to unlock the 15 Threes achievement in NBA 2K9 - Definitive Guide
Just get on a team with a relatively known and good three point shooter. Then in the game just continue to shoot threes until you recieve the achievement. It shouldn't take too long if you are playing with a good person and are boosting.
Basically, pick an All-Star Team (Perferably the West), put Game Sliders in your favor and shoot 3's. Players like Ray Allen and Kobe Bryant will speed up the process since they are good at 3's.
Best way to do this is with a player with a High 3PT%. Player's that have high 3PT% are Kobe Bryant or Ray Allen. If you are having problems you can always change the sliders in your favor.