Roger is having problems with backhands down-the-line. His contact point is too far in front, which is caused most often by setting up too close to the line of the approaching ball . . . sometimes by design and sometimes by accident, especially on clay. This results in a slight elbow lead early in the forward stroke, which prevents his racquet head from coming around in time with a full-length outward path of acceleration. This is even more troubling if he is forced to (or chooses to) bend over more than usual at the waist, which not only exagerates the elbow lead, but requires him to over-open up his shoulders and partially fall out of the shot with his upper body. Whereas the stroke path should be more out toward the left sideline, if he's too close, bends over, opens up or pulls the trigger too soon, he ends up swinging across the front of his body, which won't work for a down-the-line backhand, especially if it's a directional change off of an opponent's crosscourt shot.
MG