It's a straightforward integration to get from initial conditions of the ball throw and backboard angle to the post-bounce trajectory. Physics engines like Bullet will get you that solution very quickly. But determining which backboard angle puts the ball in the center of the hoop is not as straightforward if your physics engine is only designed to do numeric integration of the equations of motion to move a simulation forward in time. You have to run the simulation a few hundred times with different backboard angles to determine which setup puts the ball where you want it.

And that process needs to be done for all possible incoming ball trajectories that would hit that point of the backboard in order to figure out what backboard angle will maximize the number of shots that go in.