Choosing which side of the tee box to play from is all about playing the odds. If you are playing a draw (right handed players) you want to set up on the left side of the tee box and aim out to the right. The fade you want to set up right and aim left. The thought behind it is if you hit it straight you will be ok if it draws/fades it will be perfect. In the case of a double cross you have a little more wiggle room versus playing the shot from the opposite side of the tees. I hope this makes sense.