When baseball fans watch a batter strike out with runners in scoring position, the reaction is often immediate.
Shorten the swing. Put the ball in play. Stop swinging for the fences, they lament.
But new research suggests the answer may not be that simple.
A newly published study co-authored by Scott Powers, assistant professor of sport analytics and statistics at Rice, and Ron Yurko, assistant teaching professor and director of the Carnegie Mellon Sports Analytics Center, analyzed newly released Major League Baseball swing-tracking data to examine one of baseball’s most debated questions: Should hitters change their swing with two strikes?
For Powers, the question isn’t just theoretical.
Before joining Rice, Powers spent five seasons with the Los Angeles Dodgers, including three as the club’s director of analytics, before serving as assistant general manager for the Houston Astros. He earned a World Series ring with the Dodgers in 2020 and another with the Astros in 2022.
The paper, “Swinging Fast and Slow,” was recently published in The American Statistician. Using MLB swing-tracking data released publicly in 2024, Powers and Yurko analyzed bat speed and swing length to better understand how hitters adjust their approach as the count changes.
“What we found is that there’s really a tradeoff,” Powers said. “When players slow down their swings, they do make more contact, but they also sacrifice power.”
That tradeoff largely balanced out in the data.
“The takeaway from this is that it’s not clear batters get better results by slowing down their swing speed as the number of strikes increases,” Powers said.
Yurko said one of the study’s biggest surprises was how closely the findings aligned with traditional baseball wisdom.
“Batters can reduce their strikeout rate by changing their swing length based on the count, such as choking up on the bat with two strikes,” Yurko said. “As statisticians working in sports, we usually do not see such clean results.”
During Powers’ time in MLB front offices, debates about two-strike approaches happened constantly, especially after high-profile strikeouts in critical moments.
“When I was working for the Dodgers, every time one of our batters would strike out in a big situation, I would get texts from my friends complaining about the approach of the batter,” Powers said. “But I never understood. Is the batter actually trying to swing for the fences?”
The newly available swing-tracking data finally allowed researchers to explore that question in greater detail.
“We know the speed and the length of every swing,” Powers said.
One of the study’s biggest findings involved how researchers interpret sports data itself.
At first glance, the data appears to show hitters swinging harder are actually more likely to make contact, a result that didn’t make intuitive sense. Powers said the challenge was recognizing that swing speed is influenced by the pitch itself and by how hitters adapt in real time.
Yurko said the researchers initially saw a similar pattern when they first explored the data.
“When we first glanced at the data from a high level, we observed that faster, longer swings appeared to have higher quality contact,” Yurko said. “But this ignored the context of how MLB records the swing length and bat speed measurements, along with various confounding factors such as a batter’s ability to recognize pitches and timing.”
Their findings underscore a lesson that extends well beyond baseball.
“Our study ultimately illustrates how statistical thinking is still highly relevant in today’s age of massive datasets and AI tools,” Yurko said.
The researchers also found that some hitters appeared more effective than others at adjusting their swings with two strikes. Powers pointed to Seattle Mariners center fielder Julio Rodríguez as one standout example.
“The best type of two-strike approach is to shorten your swing without slowing it down,” Powers said. “Julio Rodríguez stood out as somebody who does that particularly well.”
While MLB teams have access to far more sophisticated internal tracking systems than the public data used in the study, Powers said he hopes the research helps students and analysts think more carefully about how baseball data is interpreted.
“The thing I hope students doing baseball analytics research in the future will take away from this study is that you can’t just take swing-tracking metrics at face value,” Powers said. “You have to think carefully about how these things are being measured and what they mean.”
The growing demand for analytics talent has also created opportunities for Rice students. Powers said four students from the university’s sport analytics program are heading to work for Major League Baseball organizations this year.
Powers said the project was also meaningful as a collaboration with Yurko, whose expertise helped shape the study’s statistical modeling.
“Through working with Ron, I learned a lot about how to conduct analysis that could answer an interesting question and present it in a way people could understand,” Powers said.