Scott Powers knew the question intimately. During his five seasons with the Los Angeles Dodgers—where he won a World Series ring in 2020 as director of analytics—he would get text messages from friends every time a batter struck out in a crucial moment, all of them insisting the same thing: the hitter needed to shorten their swing with two strikes. Those debates followed him to the Houston Astros, where he earned another championship ring in 2022. Now, as assistant professor of sport analytics at Rice University, Powers finally has data to settle the argument.
The newly published study "Swinging Fast and Slow," co-authored by Powers and Ron Yurko, director of the Carnegie Mellon Sports Analytics Center, uses Major League Baseball swing-tracking data released publicly in 2024 to examine one of baseball's most enduring questions: should hitters fundamentally change their approach when facing two strikes? The answer, it turns out, is more nuanced than generations of baseball fans—and front-office texters—have assumed.
Using detailed measurements of bat speed and swing length across thousands of plate appearances, Powers and Yurko discovered what Powers calls "a real tradeoff." When batters slow down their swings, they do make more contact, reducing strikeouts. But slowing down also sacrifices power. These benefits and costs largely balance each other out statistically, meaning batters don't necessarily get better overall results simply by easing up with two strikes.
What surprised Yurko most was how closely the findings aligned with traditional baseball wisdom, even if that wisdom points in a different direction. "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 explained. "As statisticians working in sports, we usually do not see such clean results." The data validated one piece of conventional baseball thinking—shortening your swing does help you make contact—while complicating another: whether that adjustment actually improves your chances of success.
The research revealed something even more important: how easy it is to misinterpret sports data entirely. When the researchers first examined the swing-tracking measurements, the raw numbers appeared to show that hitters who swung harder were more likely to make contact. That counterintuitive result made Powers and Yurko dig deeper. They realized that swing speed is heavily influenced by the pitch itself and by how batters react in real time. Faster swings often come on pitches easier to hit. Ignoring that context created a statistical illusion.
"You have to think carefully about how these things are being measured and what they mean," Powers said, offering a lesson that extends far beyond baseball diamonds. The study demonstrates that statistical thinking remains essential even in an era of massive datasets and artificial intelligence.
The researchers did identify individual excellence within their findings. Seattle Mariners center fielder Julio Rodríguez emerged as a standout example of someone who excels at the ideal two-strike approach: shortening his swing without sacrificing speed. His ability to execute what Powers calls "the best type of two-strike approach" suggests that while the broad statistics show tradeoffs, elite hitters can thread that needle.
While MLB teams access far more sophisticated internal tracking systems than the public data used in this study, Powers hopes the research changes how future analysts think about baseball statistics. The message is simple but profound: the numbers only tell you what they measure, never the whole truth.