PROFESSIONAL BOWLERS AND TOP COACHES long have disagreed over the many subtle manifestations that can take place in the downswing. It is understandable why this aspect of the game provokes such controversy, because it is the backswing that’s often modified to accommodate the specific physiology of the bowler.
Some modifications work well; some do not. The downswing is more stringent in keeping with fundamental technique; a complicated process, it affords little deviation.
Consider: In the downswing, your arms, shoulders, legs and hips all move at the same time, with varying speed and directions in order to set the ball down on a specific board on the lane. Is it any wonder many beginners frequently roll gutter balls?
The key to a successful downswing is found primarily in the transition point between the end of the backswing and the beginning of the downswing. Concentrate on letting the weight of the ball initiate the downswing. If this is done, it affords the best opportunity for the arms, hips and legs to coordinate so as to provide an ideal swing speed, leverage and the correct swing direction. If all the parts move in correct sequence, you will be more consistent.
The downswing movement starts from the ideal position at the top of the backswing. Your best preparation is to create a strong coil with the upper body so there is tension between it and your lower body. This tension allows the weight of the ball to easily drop into the ideal swing on the way down.

