I'm not certain the plate or even "letting the ball get deep" can be used as an actual reference. Think of how quickly the ball moves 12". It seems impossible to say "I'm letting this one get to the back corner of the plate" before swinging. Perhaps what actually happens is you get used to hitting a certain part of the ball with a certain bat angle adjustment based on the pitch location. The more it is practiced with a tee and front soft toss the more familiar it becomes and the greater likelihood of driving it to right center which is most often the goal on that outside pitch.
