Baseball Curveball (CU)

In baseball, pitchers at the highest level must use a variety of pitches to get hitters out. Simply throwing one pitch repeatedly will not get it done against top competition. One pitch that lots of pitchers like to throw is a curveball. Keep reading to learn what a curveball is, how to throw it, and the different variations of the pitch.

Definition

Officially, a curveball is a pitch that breaks more than any other pitch in baseball and is designed to be much slower than other pitches to throw hitters off balance. Oftentimes, when it is thrown correctly, batters will swing and miss over the top of the curveball as well as be early on their swing timing. A curveball is one of the more unique pitches in baseball. In 2022 in the MLB, around 10% of the pitches that were thrown were curveballs. That ranks fourth behind fastball (49%), slider (22%), and changeups (11%).

How to Throw A Curveball

There are a few different ways to throw a curveball, and each one has a slightly different grip. For the purpose of this piece, the most basic curveball grip will be discussed. The initial step involves holding the ball in your hand so that the two seams on the ball run parallel to your fingers. Next, you place your middle finger on the inside of the right seam (left if you are left-handed) and place your index finger directly next to it. Lastly, your thumb should be directly below your index finger underneath the ball, and your other two fingers are on the other side of the ball. 

After you get the grip down and go through your throwing motion, the final step is the release of the ball. When you release a curveball, you should snap your wrist so that your index and middle fingers end up pointing toward your head. This is how the spin in the curveball is generated. 

Variations

There are a few different variations that have developed off of the basic curveball. One of them is known as the “12-6” curveball. While a basic curveball has more of a diagonal break, “10-4/2-8” in terms of a clock, a “12-6” curveball just breaks straight down, hence from 12 to 6 on a clock. 

Another variation is the “slurve,” which is a close mashup of the curveball and the slider. A slurve has the opposite effect of the 12-6; it breaks more horizontally than a regular curveball. Moreover, some pitchers throw a power curveball. Power curveballs sacrifice some spin and break to be faster than the average curveball.

Lastly, there is the knuckle curveball. Unlike the regular curveball, where the two fingers on top of the ball are straight, pitchers who throw a knuckle curve have their fingers bent a little when they throw the ball. This pitch may be slower than a typical curveball, but it creates more spin and greater movement when thrown properly.

History of the Curveball

Pitchers first came up with the curveball in the mid-late 1800s as a new way to try and get hitters out, as pitchers had just been throwing one pitch up to that point. Since the nature of early baseball was that pitchers were not supposed to deceive the hitter, curveballs were considered a dishonest pitch when they were first used. No rule could be created to outlaw the pitch, however, and over time, the pitch grew in popularity. 

Most historians often credit Candy Cummings, who pitched in the 1870s, for popularizing the pitch. In 1869, the first major documentation of the pitch came about. That year, The New York Clipper described pitcher Phoney Martin as a hard pitcher to hit because his pitchers never came in a straight line but rather in a curve.

Best Curveball Pitchers

• Bert Byleven
• Clayton Kershaw
• Sandy Koufax
• Greg Maddux
• Pedro Martinez
• Satchel Paige
• Nolan Ryan
• Tom Seaver
• Warren Spahn
• Adam Wainwright

FAQ