Here, natural forearm pronation has brought Roddick's strings to face much more forward than they were a split second earlier, but they will still brush upward and across the ball at an angle, creating a mix of topspin and sidespin.
Some, but not too much, forward lean helps Andy drive the ball forward with more power. It's ideal to keep looking up at the ball through contact, but it's also awkward for many players, apparently including Andy.
