How To Throw a Knuckle Curve

There are a lot of different types of pitches that you can throw in baseball. One of which is the knuckle curveball.

This guide will tell you not only how to throw a knuckle curveball, but also all of the details on how it works and the mechanics of the throw.

What is a knuckle curveball based on?

In order to understand the way that a knuckle curveball is thrown, you first need to know how a regular curveball is thrown. Here is a brief description of how a regular curveball is set up and thrown:

  • Your index and middle finger should be parallel with one another and the only fingers flat on the ball.
  • Your thumb should be placed in a comfortable position on the opposite side to the ball for stability.
  • The rest of your fingers should be curled up into your palm and not resting on the ball.
  • When you throw and release the ball, there is a slight exaggeration on the wrist being further from your body than your elbow is. This is called the pronation of your arm.
  • All of this will produce a straight curveball, or a curveball that is always on target and doesn’t have a significant spin like other curveballs variations.

Is the grip different on a knuckle curveball?

Yes. The grip on a knuckle curveball is slightly different to that of a regular straight curveball. But the knuckle curveball is based on the straight curveball; because of this, the grip and throw are still relatively similar.

Here is a detailed breakdown of the grip for a knuckle curveball:

  • The index and middle fingers should be placed on the ball in the same way as they are for a curveball, but the index finger should be curled all the way under so that the fingernail is flush with the ball. The first knuckle of your index finger should be touching the ball just about.
  • Your thumb should be in the same place as it is for a curveball, on the opposite side of the ball to your index and middle fingers. This positioning will allow for stability when throwing the ball.
  • The other two fingers on your throwing hand should be curled up into your palm and not touching the ball in the way that your index and middle fingers are.

Although the grip for a knuckle curveball is similar to that of a regular straight curveball, the reason that it is called a knuckle curveball is all in the grip.

The way that your index finger is curled up against the ball so that the first knuckle near the tip of your finger is touching the ball, and so that the middle knuckle of your finger is sticking out away from the ball, is the reason for the name.

Why is the grip important?

This specific grip is important for a knuckle curveball because it makes the throw what it is. This kind of grip on the ball has been said by pitchers to give them the most amount of rotation when they are actually pitching the ball.

This is ideal for the spin that you want to put on the ball in order to take the batter by surprise.

The knuckle of this finger should also be pointing towards the batter, just like your finger would point to a batter when you a throwing a beginner curveball.

How should the knuckle curveball be thrown?

In a similar way to the regular curveball, the knuckle curveball will have the same motion. Your body and arm movements and swing should not be any different to when you are throwing a regular curveball.

But you will add a little bit more pronation at the end of the throw upon the release of the ball.

Pronation is simply how deep the angle is of your wrist away from your body compared to your elbow. The more pronounced the pronation, the more spin and curve you will have on your ball.

How can I perfect my knuckle curveball?

The one part of throwing the knuckle curveball that a lot of pitchers will say is the hardest is the knuckle part. Yes, the main part of the throw.

You may find it hard and uncomfortable to have your finger in that position on the ball, but practice will always make perfect.

The best way you can get used to the knuckle placement on the ball is to carry a ball with you every so often and simply carry it in the knuckle curveball grip.

This way, your hands will remember the grip like muscle memory.

Are there any other tips and tricks?

Since your nail of your index finger will be on the ball a lot, and when you throw the ball, a little bit of strain will be exerted on this nail alone, it could become damaged.

The best way to avoid this is to keep your fingernails short and to put nail polish on them. It does not matter if you go for a clear coat or a bright pink, the added layer of polish and enamel will work to harden your nails and protect them from the potential damage that the knuckle curveball grip can cause.