Elbow has nothing to do with balance. If that was the case; Barnes, Robert Smith, and others with bent elbows would be off balance. A. His shoes appear cheap (could be wrong). But his slide never stops; almost as though he has Easy Slide on the bottom of his shoe. B. When he slides, his slide foot is pointed at the 7 pin while his shoulders are pointed towards the 10 pin. His lower body is not working well with his upper body. C. His left arm is almost tucked at his side and not out away from his body to help with balance. D. I think he starts too far back from the foul line. If he started a little closer to the foul line and shortened his steps, that could aid in helping with balance as well. Those are all the things I notice.