Plus40 pretty much got it.
The pin position at 3 3/8 from the PAP provides maximum flare potential for that core and ball combination.
Move the pin towards the PAP and it will flare less and hook earlier. Move the pin further away and it will flare less and hook later.
Higher pins in relation to the center of the grip create length lower pins give earlier hook.
The same with the CG, as you move it closer to the PAP the ball will roll earlier. Further away the ball will roll later.