At 26, the third-year big leaguer is becoming a poster boy for reverse-split specialists.
"I've always liked facing lefties," Boxberger said, "just because I've been able to use what I want to use against them."
This season, Boxberger has essentially been a two-pitch pitcher: fastball and changeup. His cutter has become obsolete, while his changeup has been nasty.
"It's not unlike [Mariners closer] Fernando Rodney," said Rays manager Joe Maddon. "It's very similar to that. I don't think the hitter sees him well. Because of where the ball ends up and how it moves, it can even be more difficult for a left-handed hitter. The changeup really is that good."
Boxberger can't pinpoint the reason behind his splits, but the movement on his changeup coupled with his cross-body throwing motion have certainly helped.
"From what I've heard guys telling me, it's harder to pick up, I guess," he said. "I'm not really sure. It's been working."
Boxberger has been pretty darn good against righties, too. His .142 opponent average ranks third among American League relievers, and he had not allowed a run in 15 straight appearances.
"The way the game's going and how it's changing, it's a different evolution of the lefty specialist," Boxberger said. "You can be either a lefty or a righty. It could be trending that way."
"That's another thing that fans have to get used to," said Maddon. "There's this whole group of pitchers out there that are better to the opposite side for different reasons."
Aaron Leibowitz is an associate reporter for MLB.com.