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A Guide to Throwing a Curveball

The curveball is one of the more unique pitches thrown in baseball. Sometimes referred to as the “Uncle Charlie,” the curveball moves differently compared to other types of throws and has become a favorite alternative to normal pitches like a fastball or changeup.

To throw a curveball, start with a comfortable grip on the baseball. When releasing the pitch, snap your wrist downwards with the thumb releasing from the ball first. You’ll know you threw a good curveball when the ball drops before getting to the catcher.

Overhead view of a hand holding a baseball demonstrating how to grip a curveball

Throwing the perfect curveball can be difficult to master, so the below guide will walk you through various aspects of the pitch, including what makes the curveball move the way it does and some drills you can practice to improve your throw. By the end of this article, you should be equipped with all the tips you need to successfully pitch a curveball.

Throwing Curveballs vs. Traditional Pitches

Curveballs are unique pitches in that they are thrown completely differently than any other type of pitch:

  • Generally, throwing a baseball involves placing the fingers on certain points of the ball, usually with the pitcher’s fingers on the seams to manipulate how much movement the ball will have after it is released. Curveballs, on the other hand, require the pitcher to use their wrist to produce the curving effect.
  • Curveballs tend to be slower pitches than traditional pitches, both by design and because of physics. A slower throw generally means more movement, which is what you are looking for in curveballs.
  • Because a pitcher must snap their wrist and contort their arm to get the curve effect, it is harder to throw the pitch with as much velocity as a traditional pitch.

The Science Behind Curveballs

When imagining a typical baseball being thrown, you’ll likely picture the ball moving in a consistent arc over the pitcher’s mound and toward the catcher. Curveballs travel a little differently, with some dropping or looping anywhere from seven to 20 inches from the release point to the catcher’s mitt.

While gravity may contribute to this sudden drop, there’s a little more physics involved—specifically the Magnus Effect.

The Magnus Effect

When throwing a fastball, the pitch has a large amount of backspin because of how the ball is released – it rolls off of the pitcher’s fingers. While in the air, the ball faces high-pressure zones in the air ahead and below.

According to the Babe Ruth League, “the baseball’s seams augment the ball’s ability to develop a boundary layer” (a layer of “fluid” in those high-pressure zones), which places a greater differential of pressure above and below it. This, plus gravity’s effect as the ball rides on and into increased pressure, means the fastball will fall less often.

A curveball has the opposite effect. This pitch is thrown with topspin instead of backspin because the pitcher is snapping their wrist in a downward fashion, which creates a higher pressure zone on the top of the ball. Thus, the pitch tends to move downward initially, and gravity helps push the ball further down.

The result is a pitch that starts up high and travels with a downward force from the point of release from the pitcher’s hand.

Changing Perception

In 1984, aeronautical engineer Ralph Lightfoot used wind tunnels to test and prove that a curveball actually curves. However, there may still be evidence that the curveball has a hidden advantage of optical illusion.

Essentially, it works like this: when an object is spinning and moving in the air and is viewed head-on by a person, the brain interprets the overall motion correctly. No matter which way the object moves, you can interpret the object’s motion correctly.

But with a curveball, the pitch starts in the batter’s direct vision out of the pitcher’s hand; as it comes closer to the plate, though, the batter’s peripheral vision then registers the ball.

In addition to what the batter has seen out of their central vision, the peripheral vision confuses the brain as to how much the ball is moving downward. The images cross and distort what the mind thinks it has seen from two different angles. Therefore, the batter thinks the breaking of the pitch is either bigger or smaller than it actually is, and they swing and miss.

Eye Depth

The reason why curveballs are devastating to batters is because of “eye depth,” which is connected to the “optical illusion” they seem to produce.

In baseball, a pitcher tries to keep batters from guessing which pitch they will throw next. So, in a pitching sequence going from a fastball that is straight and at the upper-chest level to a curveball that is much slower and moves like a loop from chest level down to the knees, the batter’s eyes can get confused.

This is “eye depth” in action, where the batter sees the first pitch at one level and then the next seemingly at the same level before it drops.

Warming Up Before Throwing Curveballs

Before we get into how to throw a curveball, you must first warm up your body and arm.

Dynamic Stretching for Pitching

When it comes to stretching and warming up for any athletic event, the first rule is to perform dynamic stretching.

Dynamic stretching is when you stretch while in motion; this is the opposite of static stretching, in which you are stationary. Dynamic stretching is important because it allows the muscles to warm up without feeling stiff. It also prepares the body for the activity that is about to happen.

Using Resistance Bands to Warm Up the Pitching Arm

The best piece of equipment to have when warming up your pitching arm is a resistance band. These bands are great to ensure the arm muscles are warm and increase their ability to resist force.

Long Tossing to Warm Up the Pitching Arm

Along with stretching and using resistance bands, be sure to do some light and long tosses before pitching. The light tossing is similar to stretching and the resistance bands in that they allow the body to get ready for the activity. 

Long tossing is when a pitcher will throw a ball as far as possible, from one side of the outfield to the other. This gets the shoulder warmed up, and the rest of the body ready to go due to the wide range of motion involved. 

When long tossing, be sure this is the last warm-up you do before pitching. The reason is so that you do not over-exert yourself before trying to go out and throw for a long duration. 

How to Throw a Curveball

Once you understand the physics behind curveballs and what contributes to how they achieve their notable “looping” effect, you’re ready to try throwing the pitch! But like any other pitch in baseball, you’ll need to make sure you have your grip down first.  

Note: There are different types of curveballs in baseball (knuckle-curve, circle curve, slurve, etc.), but for the purposes of this article, we will focus on the standard curveball. Of course, once you’ve mastered the basic curveball, you are encouraged to try to adjust your technique to achieve these other variants of the pitch.  

Gripping the Baseball for a Curveball

To get the best grip on the baseball for a curveball throw, follow these steps:

  1. Imagine you are grabbing a cup of water; with your dominant hand, hold the baseball in a similar manner, with the ball’s seams facing vertically. Your pointer and middle fingers should be split across the outside seams facing away from your body.
  2. Place your thumb on the lower part of the seam (closest to your body), with your remaining two fingers tucked underneath. 
  3. Your hand should naturally form a “C” shape, with the baseball’s horseshoe stitch pointing toward the palm. 

Note: Make sure your hand is comfortable when gripping the ball; if you feel like your fingers have to strain to achieve the correct placement from the steps above, you may adjust them as needed until you’re more comfortable.

Bottom view of a hand holding a baseball demonstrating how to grip a curveball
Bottom view of how to grip a curveball
Overhead view of a hand holding a baseball demonstrating how to grip a curveball
Overhead view of how to grip a curveball
Side view of a hand holding a baseball demonstrating how to grip a curveball
Side view of how to grip a curveball

Throwing the Curveball

As mentioned earlier in this article, the process for throwing a curveball will be different than almost any other pitch. With this throw, you’ll want to concentrate on your wrist rather than your fingers. 

When throwing the curveball, start by following all the steps you usually would with a traditional pitch:

  • Your elbow should be positioned in the same way and follow the same motion as any other pitch. Your arm should form a 90-degree angle right before you release the ball, with the elbow eventually turning toward the body. 
  • As you throw the ball, squeeze your triceps to get the follow-through; this will also help alleviate any extra pressure on the shoulder and/or the elbow. 

The only thing that will change with the curveball is how you release the ball:

  1. Right as you release, snap your wrist downward; this will add pressure on the ball and force it to drop during its arc. 
  2. The ball should tumble out of your hand, leaving your thumb first.
  3. The ball should then roll off the index and middle fingers, which are responsible for adding the final topspin effect. 

The more you snap your wrist, the more of an effect it has on the ball, producing a greater downward motion. If you want to confuse the batter even more, you can slightly rotate your wrist as you snap the pitch forward; this will make the ball drop and move toward the side. 

What Makes a Good Curveball?

The best curveballs are those that move in a clockwise 12 to 6 or 1 to 7 motion. Ideally, curveballs should loop downward with little to no horizontal movement.

Without these looping effects, the ball will more likely be hit by the batter since they’ll be able to see it more clearly. To achieve these effects, here are a few things you can do:

  • First, focus on the wrist-snapping motion. As mentioned above, the greater of a snap you can put into the pitch, the more likely the ball will roll off your fingers and tumble toward the lower part of the batter’s strike zone, as desired.
  • Another technique you can try: when releasing the pitch, point your index finger toward where you want the ball to go. In other words, when you snap your wrist down to throw the ball, the index finger should fall forward and toward the strike zone. If your finger is pointed up or directly toward the ground, your release point needs adjusting. 
  • The final thing you can do to achieve a solid curveball is to lean heavily on the effect the middle finger and thumb have on the baseball; this is how you can manipulate the number of spins your curveball has. 

Curveball Drills for Practice

Once you have the basic curveball technique down, there are a few drills you can practice to improve your throws. The following exercises can help you perfect your arm and wrist movement and ensure consistency with every pitch.  

Beginner Drills for Curveballs

This first group of drills are designed for beginners and are great for young pitchers new to throwing curveballs.*

*Note: Most doctors and baseball coaches agree that the curveball can have a devastating effect on a young pitcher’s shoulder and arm because of the motion it takes to produce the pitch.

For this reason, practicing curveballs is not recommended until the pitcher’s cartilage and tendons have fully developed (usually around the age of 13), and they have understood how the body should properly move with pitches.

For a more in-depth explanation, read my article on what pitches should a 12-year-old throw

Snap Drill for Curveballs

The snap drill is really simple, can be done anywhere, and all you need is a baseball. It’s great for beginners because it is intended to get a pitcher used to throwing a curveball pitch and snapping their wrist. 

  1. To start, form your grip on the baseball just like you would for a curveball. 
  2. Then, snap the ball straight up into the air. It should have greater vertical rotation and less horizontal rotation. Emphasize the middle finger and the effect it has on the pitch when you are doing this drill. 

Start slow and perfect the spin; when you get that down, slowly pick up the snapping action to go faster and faster to see how many rotations you can get.

Soft Toss Drill for Curveballs

This next drill is intended to get someone thinking about how their upper body affects the pitch. 

  1. With a partner, stand at about 30-40 feet apart; you will do a soft toss back and forth. Each of you will be on one knee, with the stride leg (your left leg for right-handed pitchers, right leg for left-handed pitchers) in front.
  2. Keep your pitching hand separated from your glove and grip the ball. Throw the pitch to your partner, really focusing on the wrist action and how your upper body mechanics play a role in this pitch.

Be sure to mix in a fastball with every set of five curveballs thrown to ensure you are not overworking your arm or elbow. Once you have done this drill, the next step of this drill will be done similarly:

  1. Set up like the previous drill, you and a partner 30-40 feet apart. But, instead of being down on one knee, you are both going to be standing with your stride leg out in front like you are pitching.
  2. You can start with the ball gripped in your glove this time, with your weight on your back leg, and throw the ball to your partner. For reference, you can have your partner squat like a catcher to simulate throwing on a mound.

Continue to this for a few rounds, alternating between you and your partner throwing curveballs and fastballs.

Advanced Curveball Drills

Once you have completed the first set of drills and repeated them until you have perfected your curveball, there are a few more drills you can do to maintain your pitching motion and make sure you still throw the pitch correctly.

Pad Drill for Curveballs

This is a great drill for warming up in a bullpen or on an off-day for a pitcher because there is no actual throwing involved. It requires a pad or a pillow and a partner to hold it. 

  1. First, have the person with the pad or pillow hold it up where the pitcher’s release point is. 
  2. The pitcher will then grip the baseball like normal and then stride through. As they get to the pad, karate chop the cushion. 

The purpose of this drill is to ensure that the pitcher is turning in their hand and snapping their wrist at the release point. Hitting the pad with the karate chop motion will reinforce this in their mind because the ball should be released at the point of impact. 

Broomstick Curveball Drill

This drill aims to make sure the arm motion when throwing the curveball is consistent in every repetition.

  1. To start, have someone hold out a broomstick at just over shoulder height in front of the pitcher. The pitcher will then begin their throwing motion for their curveball, and when they get to the broomstick, they will release the ball with the snap of their wrist, with the person holding the broomstick dropping it downward. 
  2. The pitcher should have their hand follow the broomstick down to complete the appropriate motion. 

One thing to keep an eye on is to ensure that the ball is released before the hand gets to the broomstick to have the release point be where it should be.

Throw the Bone Drill for Curveballs

This drill involves a little DIY and requires you to attach two baseballs on either end of a rod, stick, dowl, etc. about 12 inches long.

All the pitcher does is grip the bottom ball on the stick and throw it like their normal curveball. If the stick, or “bone,” moves end-over-end, the pitcher threw the pitch correctly and released it at the right time.

If the “bone” has any horizontal movement or flies upwards, your release point is not where it should be.

Alternatively, you can tape two wiffleballs together to get the same effect.

Finishing the Pitch Drill

This final drill is a little complicated, but it is very useful for those pitchers who are having trouble “finishing the pitch.”

Finishing the pitch means the pitcher is not following through with their arm as much as they should be. The follow-through is especially important for a curveball because a pitcher who does not finish will not get the full downward tumbling motion they desire.

  1. To set this up, you will need a catcher and an L-shaped screen. The drill starts with the pitcher on the mound, with the catcher behind the plate; the L-shaped screen should be 20 feet in front of the pitcher, at 10:00 for right-handed pitchers, 2:00 for left-handed pitchers. 
  2. The pitcher starts by throwing a fastball to the catcher. Then, the pitcher follows up with a curveball that is supposed to reach the L-shaped screen. 
  3. Initially, the pitcher might not get to the screen, but as they try and reach the screen, the drill should reinforce their finishing and begin to push their curveball towards it.

Other Simple Curveball Drills

Once you become a good pitcher, you will want to continue to progress and perform drills to maintain and improve your pitching abilities. The following drills are simple ones that require very little effort or material:

Water Bottle Drill for Pitchers

The first drill you can do is the “water bottle drill.” This drill requires only a water bottle, preferably empty. 

It’s another great substitute drill if you don’t have the resources to create the tool for the “throw the bone” exercise. It is also ideal for younger pitchers because it reinforces what the curveball is supposed to look like without the need for repeated arm usage. 

  1. Grip the top of the water bottle like you would a curveball and turn the bottle upside down. 
  2. Then, throw the bottle and snap your wrist like you would throw a baseball. 

The bottle will tumble in an arc-like fashion downwards, mimicking what the curveball should look like. Similarly to the “bone throw” drill, if the bottle has any type of side-to-side movement or flies upward instead, you’ll need to readjust your technique or release. 

Wall Ball Drill for Pitchers

Another simple drill to do would be to play wallball with a tennis ball. Continue to grip the tennis ball like you would a baseball, and toss the ball up against the wall. Really focus on your grip and your release point to ensure they both stay the same every time you throw the pitch.

Final Tips for Mastering the Curveball

To improve your curveball, practice and repetition are required. You’ll need to get the timing and your pitching motion down to produce excellent curveballs every time. However, there are a few more things you can do to continue improving these pitches: 

  • The curveball is a complicated pitch to throw and can have adverse impacts on a pitcher’s shoulder, elbow, and arm. Because of this, be sure you warm up properly before throwing every time to avoid strain.
  • As pitchers get tired, the amount of wrist action they can produce can dramatically change. Stamina affects how well the pitch is actually thrown. With this in mind, make sure you take breaks often between drills and games.
    • Try and find the best rhythm and feel for throwing the curveball. Too much wrist snapping action can hurt a pitcher, while too little can affect the pitch itself. Plus, you want to throw the pitch effectively when you are tired. In general, finding the right balance is important.
  • When a pitcher throws a curveball, they tend to tilt their head over their front shoulder, leading to a more ineffective curveball. If this happens, the curveball does not have the tumbling down effect but rather a side-sweeping motion. Keep your head straight on when throwing the pitch.
  • Perfect the art of making the curveball look like any other pitch to confuse the batter. This can be challenging because pitchers will need their wrist-snapping motion to be consistent throughout a game. However, the easiest way to overcome this is to always think “fastball” until it’s time to release the ball.
    • Keeping the same mentality when you throwing a fastball or a curveball will ensure your throws appear more consistent with one another. Also, throw every pitch – regardless of the type – with as much integrity and force as you can.

In Summary

A curveball is a great pitch to learn as a secondary throw. It can significantly affect how a batter sees the ball coming out of the pitcher’s hand, giving the pitcher a great advantage.

Be sure to practice the numerous curveball drills mentioned in this article for beginners when you first start throwing the pitch. Building up grip, snapping motion, and arm motion required to throw an effective curveball is important in the long run. And remember: always warm up properly and thoroughly to prevent injuries.

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Steve Nelson

I'm the owner of Baseball Training World. I live in Denver, Colorado and I enjoy playing baseball in an adult baseball team in the surrounding area. Read more about Steve Nelson.