After seeing what 2K has for AI's jumper in 2K13, I needed to find something better. AI didn't have that little hitch in his shot base like they have for his default for 2k13. So, after tinkering around with all the Releases and Shot bases and watching a TON of youtube videos of him playing, here's a list of what "I" think is the closest representation of his real jumper:
1) Release: 15 Shot Base: 29
2) Release: L. Aldridge Shot Base: 29
3) Release: B. Lopez Shot Base: 29
4) Release: T. Parker Shot Base: 29
5) Release: T. Parker Shot Base: K. Bryant
EDIT: The 1-4 shot bases can all be subbed out for K. Bryant's shot base. As Kobe's Sb seems to have a smoother transition between actually jumping and releasing the ball.