Here is a foul line drill to promote good balance, a solid finish position and committment at the foul line. Click for more info....
Foul Line Drill
1) Bowler gets into a finish position at the foul line. Stand on 20 looking at 10 to open the shoulders slightly.
2) You want the slide leg to be about 140 degrees (biomechanics research found elite bowlers finished in this position).
3) Be sure that the trail leg is in an appropriate position. Foot at 7 for RH or 5 for LH.
4) The trail leg should not be straight. Have the bowler bend the trial leg. I position the trail leg knee just past the center of the slide knee. Slightly to the left of center for RH and slightly to the right for LH bowlers.
5) Space the distance between the slide leg and trail leg for good balance and to achieve both the 140 degrees and the trail leg positioning. Keep in mind a good finish position and watch for sitting too much or standing too high. Shoulders should be slightly forward.
6) The trail foot is positioned at 45 degrees (not flat or straight)
7)Balance arm firm at 8 (right-handed bowler) or 4 (left-handed bowler)
8) Start with the ball down at the side. Starting down at the side promotes more balance in the drill as compared with a standard pushaway version.
9) Remind the bowler (push, relax, roll)
10) Hold this position for 1 second before beginning push.
11) Push the ball upward to the belt and relax into the swing. Watch that the bowler does not move the ball backwards at all. If a bowler moves the ball backward, you can place your hand on the back bottom of the ball and gently push it forward and then move the hand when it reaches just under the belt line. Do this a few times until the bowler gets the feeling.
12) Hold the finish position until the ball hits the pins. Expect this coaches.... It will contribute to more commitment at the foul line
COACHES OBSERVATION TIP: Watch for muscle in the upswing or down swing. I want to see a uniform flowing swing in this drill. The best place to view for muscle is the uniformity of the swing speed and the shoulder motion. These two will show you how free the swing is....
SPECIAL NOTE: Have your bowlers visually look at good finish positions before doing the drill for the first few weeks. The visual image will help them construct a good position for themself especially with your feedback.