Depending on the height from which the bowler drops the bowling ball, the ball will have a certain amount of potential energy. If the bowler bowls with a straight ball, the potential energy of the ball will not affect their game very much. It will, however, draw attention to the bowler when they drop the ball sufficiently high as to broadcast sonic reverberations of the ensuing lane-punishment for the rest of the bowlers to hear (and laugh at). Thus, it is in the straight-ball bowler's best interests to keep the ball as close to the lane as possible upon release.

Bowlers who bowl with a hook-ball have even more at stake. The more potential energy the ball has upon release, the longer it will bounce as it travels down the lane. This translates into less opportunity for a hook-ball to catch friction against the lane. Remember, the horizontal velocity is independent of the vertical velocity, hence (assuming the ball is always thrown with a force parallel to the horizon) the ball will take the same amount of time to reach the pins, regardless of how much time it spends airborne.


source: http://studentorgs.utexas.edu/bsm/

U = mgh
U = gravitational potential energy
m = mass of the bowling ball
g = acceleration of gravity
h = height of the bowling ball