One of the most complicated issues to fix in bowling is the concept of “clearing the thumb.” This refers to how consistently your thumb exits the ball as part of your release.

Thumb exit problems are so difficult to fix because the release itself only takes a split second, and we’re talking about just one piece of that. With a motion that takes a fraction of a second to complete, even the smallest change in timing can be significant. The thumb exit is also one of the last things to happen in a complex series of movements, so any number of things can go wrong before the thumb comes out of the ball. In short, there are lots of variables to contend with. With all of this in mind, it’s no surprise that many bowlers struggle to clear their thumb consistently.

A typical symptom is sticking in the thumb, causing you to loft the ball farther onto the lane and/or miss your target, usually to the inside. However, another sign of poor thumb exit timing is dropping the ball consistently or missing it at the bottom, which is more subtle.

First, let’s talk about the goal you’re trying to achieve: a consistent timing of when the thumb comes out of the ball. Most bowlers view the release as when you let go of the ball. When bowlers incorporate grip pressure and try to “let go” at the same time, inconsistency is bound to happen. Make no mistake: you can’t completely eliminate grip pressure; however, you can minimize it.

I prefer to look at the release this way: it’s when the ball lets go of you. With proper fit and technique, the ball should have no choice but to come off at a specific moment in time, every time. A bowler’s “flat spot” at the bottom of the swing should be that time. So, the overall goal is to get the ball fit and your game to allow your ball to come off your hand in the flat spot of your downswing.

As I just mentioned, the potential causes of an inconsistent thumb exit are many. They include fit problems, timing issues, and turning the hand early, to name the most common. It’s best to get the problem diagnosed by a certified coach, but here’s how you can start to troubleshoot the problem on your own.

Fit issues

The first step is to identify a potential fit issue. A quick way to know if you might potentially have a fit problem is to simply try to throw the ball while consciously pressing your thumbnail to the back of the thumbhole. I’ve seen people who think their fit is good lose the ball completely and throw it behind them when doing this. This is a pretty clear indication that you are “holding onto it” throughout the swing.

Most likely, when you do this, you’ll feel a moment where you need to bend your thumb and grip the ball. This is increasing your grip pressure, and now that you’re holding onto the ball, you need to let it go again during the release. Again, if you’re the one letting go of the ball, it’s not likely that you’ll be able to do it consistently without a ridiculous amount of practice and repetitions. It’s far better to adjust your fit to give you a better chance.

Assuming that your overall thumbhole size is correct, fit issues causing an inconsistent thumb exit are generally related to one of three things: pitch, span, and taper. While it would be tempting to say that there’s one primary cause, fit is a combination of factors that can rarely be evaluated in a vacuum.

More often than not, too much reverse pitch will cause you to squeeze. This is often paired with too long of a span. While this is comfortable for many bowlers, it is likely contributing to your inconsistency at the release. On the other hand, a span that is too short can also cause you to squeeze, because the ball isn’t laying in your hand properly. Have your grip evaluated by a certified pro shop professional.

The taper of your thumb can also contribute to thumb exit issues. The more taper that exists at the top of your thumbhole (the wider the hole is at the top relative to its size below that), the faster your thumb will exit on its own. This feeling can often cause excessive grip pressure. It might make sense to reduce your taper: the more cylindrical your thumbhole, the more likely you’ll have the thumb exit at a normal speed. Of course, if your thumb is naturally tapered, you need this taper for proper fit, so it’s important to evaluate this properly.

The mistake I see a lot when it comes to taper and hole size is that people often test the fit of their ball by putting their hand in the ball from the top with their fingers away from them, and then pull the thumb out. Unfortunately, this can be misleading. The ball exits easier when your hand is underneath it, like how you release the ball, so by testing from the top you get the impression that the thumb feels tighter than it really is. As a result, the thumb is opened up or tapered too much, and you end up creating grip pressure. Always test fit from under the ball, rolling it off your hand.

One final important note about fit: almost no one’s thumb is perfectly round. If your thumbhole is not oval, it is most likely not right and is causing you to squeeze. If your pro shop can’t or won’t drill ovals, you should probably go elsewhere.

Physical issues

Assuming your fit is good (or that you’ve had it fixed), there are a few physical reasons for thumb exit inconsistency. First, it’s possible that you’re not as inconsistent as you think, but that your flat spot is too short to take advantage of your game. Beyond that, there could be inconsistencies earlier in your approach that cause you to squeeze the ball occasionally. These generally relate either to later timing than usual or turning your hand early.

Lengthening your flat spot

The flat spot is essentially your release zone. The longer it is, the bigger your margin of error for minor inconsistencies in your release. Great bowlers not only repeat shots very well, but they also don’t suffer from inconsistencies as much as most people because their flat spots are generally longer and more forgiving.  There are plenty of ways to lengthen your flat spot:

  • Change your follow through: a lot of people lift up through release, shortening their flat spot. Follow through more toward the pins, and you’ll elongate your release zone.
  • Change your vertical swing plane: the more vertical your swing plane, the more likely that your flat spot is shorter. Creating shallower swing planes by having a longer slide, a lower backswing, and earlier timing into the swing can contribute to a bigger release zone
  • More knee continuation: this helps to continue shifting your momentum forward despite your feet having stopped moving, elongating your flat spot.

When it comes to the release zone, a few inches can make a huge difference in your consistency. Any of these minor changes can bring big returns in your game by allowing a bit more forgiveness.

Timing inconsistencies

Regardless of whether you are a roller-timing bowler or a leverage-timing bowler, there can still be minor inconsistencies in your timing from shot to shot. This can contribute to thumb exit issues because, generally speaking, earlier timing causes the ball to come off early, and later timing causes the ball to come off later. Keep in mind that I’m using the words earlier and later here in reference to your normal timing, and not as a general rule related to overall timing.

So, if you are a little bit later than usual, the tendency is to pull down from the top of the swing to get the timing back to normal. Your body will do this unconsciously. This generally causes tension all the way down the arm to the grip, which creates squeeze. If you’re a little early, you’ll either tense up to slow down (and squeeze), or the ball will be ready to come off before you are and you’ll miss it at the bottom or drop it.

The two most common places for these micro-timing issues to originate are the ball start and footwork. If your feet are a little faster than usual to start, or you hold onto the ball a little bit in the ball start, you’ll incrementally delay your timing. Your brain will recognize it and correct it, but the cost might be a squeezed shot and a missed target.

Many people with release issues will work on their release, without identifying the underlying cause, so consider evaluating how consistent your timing is and work on improving your timing consistency to improve your release.

Turning the hand early

Another common culprit of inconsistent thumb exit is turning the hand a little early in release. “Helping it” almost invariably ends up with bad results, but that doesn’t stop us from doing it once in a while. Remembering to “wait for it” is a key component of a good release. If you find yourself sticking on shots that otherwise feel great, it’s possible that your hand isn’t quite in the right position, causing the thumb to be blocked and not come out in time.

Again, we’re talking about split seconds, and degrees of angle for your hand position and thumb, so very small changes can drastically impact results. Training reps are key to an effective, consistent release, even if everything else is solid.

Mental considerations

Physical inconsistencies can also be related to your mental state. It never fails to amaze me that most bowlers throw it great when they are comfortable. Sometimes, the difference between throwing it badly and throwing it like a pro is simply being comfortable with your ball reaction. For many bowlers, what you’re seeing as bad ball reaction gets translated into “helping it” instead of making an adjustment. From there, it’s a downhill slide.

Be aware of your mental state and your tactical choices when you find yourself struggling with thumb exit. Are you comfortable on the lanes? How’s your stress level? Your overall mental state will contribute to tension. Tension leads to excessive grip pressure. Excessive grip pressure leads to inconsistent shotmaking.

Is your ball reaction good? Note here that I’m not asking if it’s close. Is it good? That “close” zone is the most dangerous to shotmaking. Terrible ball reaction is obvious, and it causes people adjust. Great ball reaction is also obvious. Ball reaction that is “close” leads to the “throw it better” mentality, which almost invariably lead to turning your hand early to help it get there.


Remember that ball fit is the primary consideration when it comes to thumb exit issues. After that has been eliminated as a possible cause, there are numerous other factors to consider. While I’ve pointed out the most common, and you can probably see yourself in these examples, it’s important to remember that troubleshooting your own game is not as effective as getting a second opinion from a certified professional coach.

Tyrel Rose

About Tyrel Rose

Tyrel Rose is Bowling This Month's Director of Content. He is also currently the Head Coach for Team Canada, with over 20 years of experience coaching bowlers of all levels. Tyrel is an NCCP Competition Development level and USBC Bronze Certified coach, and a former Canadian national champion.