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The Mystery of the Knuckleball

Every pitcher has to have at least two good pitches to ‘set up’ the hitter and throw his timing off or keep him guessing. Most use a fastball as their main pitch, and the curveball is popular with younger players as pitch #2.

Too many kids, in fact, rely on the curveball since it’s easier to learn to throw it than it is to learn to hit it, and so it gets batters out and helps to win ballgames. But it’s also hard on young, growing arms.

The change-up, as we’ve discussed before, is a great #2 pitch, which is thrown more like a fastball than a curve, reducing stress on arms, elbows, and shoulders .

Another pitch, seldom thrown by youth players, is the knuckle ball. It is somewhat of a mystery, especially since so few Major Leaguers throw this pitch. But it can be so effective that those pros who do throw a good knuckle ball make it their #1 pitch!

What, then exactly, is a knuckleball? How is it thrown? What does it do?

The key to the knuckle ball, or ‘knuckler’ as some call it, is its lack of rotation. Contrary to popular belief, however, a well-thrown knuckle ball is not dead-still. Although it looks neat floating along motionless, with its seams clearly visible and the brand name almost readable, that’s not how the pros throw it. The ball must rotate a little, or ‘tumble.’

A kid can learn to throw a knuckler and use it as a terrific change-up, although his knuckler and that thrown by a professional pitcher will behave differently.

How to Throw the Knuckler

A youth’s hand is smaller than a Major Leaguer’s and the grip is all-important. It’s called a knuckle ball because it is gripped more in the knuckles than within the fingers like a fastball or curveball. But it’s not actually held by the knuckles - no one could control the release of the ball if held that insecurely. Instead, the fingertips play the biggest role, and professional knuckleball pitchers actually trim their fingernails in a very precise, specific way to enhance their control.


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The best way for a young player to throw the knuckler is to grip it with the thumb tucked under the bottom of the ball and the index finger and middle finger bent, poking straight down at the ball on the backside of the seams (see photo). The object here is to cancel out the natural backspin of the ball as it rolls off the finger. The way to do this is to extend those two fingers, or ‘flick’ them forwards as you release the ball. This will in effect, try to spin the ball forwards as the release tries to spin it backwards. They cancel each other out.

It takes a lot of practice, but once you get the timing just right, and the right amount of ‘flick’, the ball will be thrown with reduced speed like a changeup, and the spin will be little or none. The first time you see yourself do this will no doubt bring a big grin to your face!

After getting the feel of this odd release, you have to work on not ‘pushing’ the ball like a shotput - a natural tendency. Your motion has to be three-quarters overhand, like a normal fastball or change-up.

What the Knuckler Does

When thrown by a skilled pitcher at roughly 55 to 75 miles per hour (much faster than most youth players can reach with this pitch), the knuckle ball rotates between a half and one revolution as it moves erratically towards the plate. Its flight is an unpredictable and virtually uncontrollable ‘dance’ that makes it almost impossible to hit.

Once you’ve caught a Major League quality knuckle ball (or tried to), you’ll understand why catchers who catch a knuckle ball pitcher on a regular basis have a silly-looking over-sized catcher’s mitt. The ball’s path is so random that a normal-sized mitt will allow too many passed balls and advancing baserunners (providing they get on in the first place). It’s really an amazing thing to experience, and you have to see it with your own eyes to believe how this pitch moves.

Obviously a kid is not going to throw a knuckler of this caliber. So why try? Well, the knuckle ball can be a very deceiving pitch to a young hitter. The fact that you can see the seams moving as the ball tumbles your way makes it appear to flutter, and it comes in slower than expected, like a good change-up. The beauty of it is, it does not put strain on the pitcher’s arm when thrown correctly, it makes a great #2 pitch, and as the pitcher matures, improved velocity and technique can make it a virtually unhittable pitch!

How Does It Work?

The knuckle ball is a mystery of aerodynamics. Scientists understand that, as the ball slowly rotates, first a smooth side is facing the wind, then a raised edge (seam), then another smooth edge, etc. The turbulence caused by this smooth/raised/smooth surface causes lift, then loses it, then lift again, etc., causing the ball to dart towards the side with less air pressure against it (the non-turbulent side). Also, the shape of the seams causes this action to not only affect the ball side-to-side, but up and down a little as well. The ‘wobbling’ motion, while only a few inches at most, appears greatly magnified and makes it very difficult to hit.

Good luck trying it out.

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