Major League Baseball (MLB) has integrated sophisticated pitch-tracking technology into its broadcast and analytical infrastructure, allowing for the precise measurement of individual pitch characteristics. According to Statcast data, a typical splitter—a high-velocity off-speed pitch—is often evaluated by its speed, spin rate, and the resulting contact quality when put in play. These metrics provide a standardized way to assess how specific pitches, such as those thrown to batters like Philadelphia Phillies infielder Alec Bohm, perform in high-leverage situations.
How MLB Measures Pitch Performance
MLB uses the Statcast system, powered by Hawk-Eye, to track every pitch delivered in a game. For a splitter, the system records the velocity at the point of release and the spin rate, which measures how many times the ball rotates per minute. A lower spin rate on a splitter is generally desired by pitchers, as it allows the ball to tumble and "drop" as it approaches the plate.
When a ball is hit, Statcast captures the exit velocity—the speed of the ball off the bat—and the launch angle, which dictates the trajectory of the batted ball. These figures are then used to calculate the expected outcome of the hit, providing context for how effective a specific pitch was in preventing a high-quality contact event.
Understanding Splitter Mechanics
The splitter is designed to mimic the arm speed and trajectory of a fastball while inducing a downward movement that causes the batter to swing over the ball or hit it into the ground.
- Velocity: Splitters typically travel slower than four-seam fastballs, often in the low-to-mid 80-mph range.
- Spin Rate: By minimizing spin, pitchers reduce the Magnus effect, which normally keeps a ball aloft, allowing gravity to pull the pitch downward more sharply.
- Launch Angle: A low launch angle, such as 1°, indicates a ball hit into the ground, which is often the intended result for a pitcher throwing a splitter to a contact hitter like Bohm.
Why Exit Velocity and Launch Angle Matter
Exit velocity and launch angle are the two primary components used to determine the quality of contact. According to MLB’s analytical definitions, a high exit velocity combined with a launch angle between 25 and 35 degrees typically results in a home run or an extra-base hit. Conversely, a low launch angle—regardless of exit velocity—frequently results in a ground ball, which is statistically less likely to result in a hit.
By analyzing these metrics, teams can determine if a pitcher’s secondary offerings are effectively suppressing offense. If a hitter consistently produces low launch angles against a specific pitch type, it suggests that the pitcher is successfully executing their game plan to induce weak contact.
Frequently Asked Questions
What is the average spin rate for a professional splitter?
While spin rates vary by individual pitcher, splitters generally feature lower spin rates than fastballs or curveballs, often falling between 1,200 and 1,600 rpm.
How does a 1° launch angle affect a play?
A launch angle of 1° indicates a "worm burner" or a sharp ground ball. These are difficult for hitters to turn into base hits because they are often hit directly at infielders.
Does exit velocity always predict a hit?
No. While higher exit velocities are correlated with higher batting averages, the outcome of a ball in play is also dependent on the launch angle and the positioning of the defensive players.