Study finds pitch accuracy more important than speed in MLB batting outcomes

With the World Series underway, Major League Baseball clubs with their sights on the offseason might want to turn their attention to a study co-authored by researchers at The Warren Alpert Medical School, which challenges the belief that pitching speed is synonymous with success.

Anthony Napoli, MD, professor of emergency medicine, worked alongside his son Benjamin Napoli, a student at Villanova School of Business, and published their findings in The Sport Journal earlier this year. The pair and their fellow researchers randomly selected 17 games during the 2022 MLB season and analyzed 1,000 at bats, focused on pitcher handedness, speed, intended location, pitch type, and outcome. Benjamin, a pitcher himself while playing at North Kingstown High School, had long been curious about the correlation between accuracy and strike outs.

“I felt I always was an accurate pitcher,” Benjamin says. “I found that I would throw a little bit better than some of the other pitchers who threw harder than me. It had me thinking in terms of if there might be something at work other than pure speed.”

Anthony says it wasn’t just his experience working in emergency medicine that helped the study take shape, but the 20 years of time spent in academic research and the associated skills he honed during that time.

“I paired the idea he had with my experience designing studies and the statisticians and methodologists I have worked with to help put together the study,” he says.

Benjamin emphasized that games were selected as randomly as possible, including all 30 teams and game states from the 2022 season. Their findings showed that at bats in which the final pitch hit its intended spot over the plate reduced batting averages and slugging percentages by more than 50 percent. Higher pitching speed, however, was not associated with such success rates, as such pitching was more associated with lower accuracy. 

“We have pitchers that are throwing over 100 mph down the center, but that doesn’t matter as much anymore,” Anthony says. “Players have caught up to those types of velocities, so I think this study shows the pendulum may be swinging back to accuracy alongside the higher velocities.”

Benjamin enjoyed working with his father on the study, and says he would love to see a study like this expanded with the MLB in an official capacity, perhaps with a particular team or the league itself.

“Some of my favorite aspects of this study were some of the smaller things we found,” he says. “We discovered that pitches higher up in the strike zone were more successful than lower pitches. You’re always taught growing up to keep the ball down. I see some of this in the playoffs—pitchers having success with high fastballs, the importance of getting outs with off-speed pitches, or pitchers who miss their spot paying for it regardless of how fast they pitch.  

In terms of expanding such a study with help from Brown, Anthony says the door is open for further exploration.

“We had talked before about working with other colleagues around Brown to automate this or perhaps utilize machine learning," he says. “It’s a huge, manual workload looking at 1,000 pitches, but it’s interesting data that can translate to the highest level of the game.”