Uncovering the Origin of the Curveball: A Look Back in Baseball History

The curveball is one of the most iconic pitches in baseball. Countless pitchers have used it, and it's a staple of the game. But it wasn't always part of baseball. Here's a look at its history, from its earliest days to how it's measured now.

The origins of the curveball

The Baseball Hall of Fame credits Candy Cummings with the first curveball. His plaque says he "pitched first curve ball in baseball history" and "invented curve as amateur ace of Brooklyn Stars in 1867."

The story goes that Cummings got the idea as a teenager in 1863, throwing clamshells at a Brooklyn beach and watching them curve. He spent years trying to make a baseball do the same. The Society for American Baseball Research dates his first curve in a game to October 7, 1867, pitching for the Brooklyn Excelsiors against Harvard. He pitched in the National League's first season, 1876, for Hartford.

Others have claimed to have thrown curves around the same time, and nobody can prove who threw the very first one. Either way, the pitch spread quickly. It added a new dimension to a pitcher's arsenal against hitters who were used to straight pitches.

The early days

Not every pitcher mastered it, and some people doubted a ball could really curve at all. Over time, pitchers experimented with different arm angles, grips and amounts of spin.

One of the most famous early masters of breaking balls was Christy Mathewson, who pitched for the New York Giants in the early 1900s. He's considered one of the greatest pitchers of all time and was known for great control and his "fadeaway" (similar to a modern screwball) along with his curve.

The modern curveball

Today's curveballs are thrown with tighter, faster spin, and many pitchers throw harder breaking balls than pitchers of the past did. The pitch has also split into a family: the 12-to-6 curve, the slurve, the knuckle curve, the slider and the sweeper.

Clayton Kershaw, the longtime Dodgers ace, made his big, looping curveball one of the most famous pitches of his era.

Spin, sticky stuff and the rules

The spitball and other doctored pitches were banned in 1920 (a few existing spitballers were allowed to keep throwing it). More recently, some pitchers used sticky substances to increase spin. In 2021 MLB began stricter enforcement, with umpires checking pitchers during games.

How technology changed the curveball

Pitchers now have tracking systems that measure speed, spin rate and movement. In MLB, that's Statcast. Coaches and players use portable tools like Rapsodo, and a few radar guns, such as Stalker's Pro series, add spin rate to velocity. This has led to more pitch design: pitchers tweak grips and release to get the spin and shape they want. Read more in how to increase the spin on your pitches.

Using a radar gun on your curveball

A regular radar gun measures speed, not movement. That's still useful: the speed difference between your fastball and curveball is a big part of what makes the curve work. Track both and look for a consistent gap.

For young pitchers, remember the order MLB's Pitch Smart guidelines and sports medicine experts recommend: fastball and changeup first, breaking balls after those are consistent. See is throwing hard linked to Tommy John?

See our guide to the best baseball radar guns at every budget →