In my travels as a professional Coach, I see many elements of our Game that are in need of correction or adjustment, but far and away, the most common is an incorrect fit of the bowler’s thumb.
A span can be too short or too long, and occasionally, the pitches are askew, but nearly without exception, the thumb is a problem. A correctly fitted thumb is essential for allowing a relaxed swing without having to ‘grip’ the ball. Gripping the ball tightens all the muscles of the arm and creates ‘steering’ of the natural plane of motion, which leads to greater inconsistency.
When your pro shop operator delivers a ball to you after a fitting, all that should be left is a minor sanding and edge bevel for the near perfect fit, but many players take it upon themselves afterward to sand and grind away at the thumb to open it up to a looser fit. This spells disaster for their game by starting an endless task of tape in their hole, commercial texture tapes and the worst … powder.
The thumb is the cornerstone of a good fit and without argument, the most difficult part of a drillers task when fitting a customer’s ball for a simple reason – no two are alike other than in function. They come in a variety of shapes; straight, conical and what I call the ‘toe thumb,’ where the knuckle is wider than the base.
A correctly fitted thumb should be snug, very snug, but not tight. In the words of the great Walter Ray Williams, a correctly fitted thumb is one where a player should be able to insert it into the ball and let it hang without dropping it. They should be able to walk to the line and deliver the ball with only the thumb in the ball.
Yes folks, that snug. If it’s oversized or all powdered up, this isn’t going to happen. Even this snug, if your pitches are correct, the ball will come off by the force of the swing alone. It’s a delicate balance, and that’s where tapes come into play for maintaining that balance as our hands contract and expand beyond the baseline fit.
Some players have perspiration issues or swelling after extended play, so they opt for a slightly looser fit and build back up with white tape, but if I see more than three pieces of tape in a hole, the base fit needs correction. I’ve seen over 10 pieces in a thumb!
Solutions to the constant adjustment syndrome are interchangeable grips for one. These grips can be quickly inserted and removed with a tool and are drilled in variants to the base size in increments of usually 1/64 of an inch. I have six different sizes, but seldom use more than three.
Another step up is the ‘molded’ insert. A cast of the players thumb is made and an exact copy is created as an insert. These are great for the player who needs little, if any, adjustments over the course of play, as obviously, it’s a copy.
For a driller and a player, the greatest challenge is getting a useable fit for the ‘toe’ thumb. If the knuckle is wider than the base, the hole has to at least that large to insert, but now, the base is wobbling at the surface of the ball.
For these cases, the player is a candidate for an oval thumb drilling. It’s complicated and requires a mill that can make controlled x and y cuts to form it, but it’s worth the extra expense of time.
Keep these things in mind when adjusting that thumb, your driller knows best.
Wilson is a U.S. Bowling Congress Silver Instructor and an International Bowling Pro Shop and Instructors Association ball technician.