Splitting It Up: How the quest to change speeds led to the modern splitter

It’s impossible to know who threw the first pitch that was called a fastball. Most likely, some guy in the 19th century with a name like Tungsten Arm O’Doyle threw a pitch that had a lot of velocity, somebody in the crowd said, “Wow, that was a really fast ball,” and the name stuck.

In those early days of baseball, pitchers had not yet figured out how to impart spin on the ball and still get it over the plate in a consistent manner, and once they did, it took many years before breaking balls were not considered deceitful and unsportsmanlike. As such, pitchers turned to the one tool in their arsenal to make life difficult for the hitter: mixing speeds. Known at the time as “slow balls,” these are likely the first changeups to be thrown in a baseball setting.

Even as the breaking ball came in vogue, pitchers continued to mess with changing speeds, attempting new grips that would lower velocity while still looking like a fastball. One of these attempts would become known as the forkball. Thrown by essentially jamming the baseball into the space between your index and middle fingers, the forkball mostly has found use as an alternative to the curveball due to its tumbling action despite its typical classification as a changeup.

Former Red Sox and Yankees pitcher Leslie Ambrose “Bullet Joe” Bush often gets credited with the invention of the forkball, as he used the pitch to great effect in the years following the First World War, because injuries and arm fatigue prevented him from throwing a more traditional curveball. His claim, however, is a bit tenuous, even if nobody disputes the fact that he find success in the Major Leagues with it. In their 1987 book The Pitcher, John B. Holway and MLB official historian John Thorn instead credit Mike Lynch, a center fielder who played seven games for the Chicago Orphans in 1902. According to them, Lynch didn’t use it himself, but taught it to teammate Bert Hall, who played seven games for the Philadelphia Phillies in 1911.

No matter how it began, the forkball continued to grow in popularity over the decades, peaking in the 1950s thanks to Elroy Leon Face, known as The Bullpen Baron. However, the difficult nature of the pitch — trying to grip it properly when you’re not a large person can border on painful at times — and its high injury risk led to it falling out of favor over time, practically disappearing by the 1970s. But even as its usage declined, the appeal of a forkball-like pitch never left the game.

While in the minor leagues, Fred Martin experimented with a variation of the forkball in which the index and middle fingers simply sat outside the seams when gripping the baseball, rather than on opposite sides. Although he did not find success with it as a Major Leaguer, it helped him revolutionize the game during his coaching career. Working as a minor league pitching coach in the Cubs organization, Martin noticed that Bruce Sutter’s pitches lost their life — particularly his fastball — after undergoing surgery to relieve a pinched nerve in his throwing arm. Martin taught his splitter, which at the time he classified as a changeup, to the pitcher. It transformed Sutter into a pitcher that was just days away from being released to one who would find his way to Cooperstown after a 12-year career.

In many ways, the splitter’s long and complicated evolution is fitting, as it’s a pitch that’s almost impossible to classify. Velocity-wise, it’s unmistakably a changeup. It moves like a 12-6 curveball. And yet, broadcasters often refer to it as a split-fingered fastball, largely because the grip is visually similar to that of a four-seam fastball.

At the end of the day, though, I don’t think any pitcher that throws the splitter really cares what type of pitch it is — so long as it’s strike three.