I had that problem as well, the way I combat it is to concentrate on my bowling style. The most important issues are your shoulders, swing and timing. Swing and timing sort of come hand in hand, your swing should be timed with you approach, if you arrive to the approach too early you may find yourself putting too much effort into the throw and it naturally lowers your shoulder and puts your ball on an early roll. Arriving too late can make you lean too far forward (or fall on your face) which can also lead to an early roll (or injury/embarrassment). Try to have your ball at your planting foot when planting your foot and release on slide. Shoulders should be parallel with the floor (left shoulder equal height to your right shoulder from the floor), dropping your bowling shoulder generally makes your arm cross your body (as your non bowling shoulder could be close to directly above your ball) having your shoulders square will allow your follow through to pass your ear on the same side of your body as your bowling arm. Concentrating on these aspects has allowed me to be much more accurate and hence increased my average by 15 – 20 pins. Hope this rant is understandable.
P.S. I am not a coach, I have never been coached, this is just some information that I have picked up over time!
