Had you heard of Carter Capps a year ago? It's OK if you hadn't. Capps had a 5.04 ERA in parts of two seasons for Seattle when he was sent to Miami for Logan Morrison in December 2013, and given the recent presence of former All-Star closer Matt, Carter may not yet be the most famous relieving Capps in pro baseball. Even now, the entirety of the "Miami" section of his Wikipedia page is a single line noting the Morrison trade. He has four career wins and zero career saves, if you care about such things.
So if you weren't following Capps closely last season, that's completely understandable. But if so, you probably didn't notice that he just put up one of the most impressive relief seasons in baseball history -- because he did.
Usually, we're going to want to offer explanations and not just blow you away with numbers, and we'll get to that. But in Capps' case, well, the numbers are so ridiculous that it's difficult not to simply begin there. Capps is…
The hardest pitcher to make contact against, on record.
A big caveat here is that the "record" in this case goes only back to the beginning of the PITCHf/x era in 2008, though considering how the modern game has more strikeouts than ever, it's a decent bet that this could be extended to literally "of all time." Capps struck out 58 of the 118 hitters he faced this year, and while the resulting 49.2 percent strikeout rate is stellar -- third best of the more than 26,000 pitcher seasons of more than 30 innings in baseball history -- we can do better than that.
We'll grant that 30 innings isn't a huge sample. Even so, Capps isn't just first, he's first by a lot. He's the closest thing to unhittable we know of. Capps is also one of just two relievers over the past eight seasons to have a swinging strike rate over 20 percent, and again, he's in first by a lot (25.4 percent to Chapman's 20.2 percent in 2014). When you put those numbers on a chart, you see Capps is basically in his own stratosphere.
How did he manage that? Well, Capps is also...
The only pitcher to look like he's throwing harder than Chapman.
Perceived velocity is a measure of how fast the pitch appears to the hitter, measured by where the ball actually comes out of the pitcher's hand. Though everyone knows the rubber is 60 feet, 6 inches from the plate, we also know that pitchers release the ball from somewhere closer than that. The average is around six feet, meaning the ball only travels approximately 54 feet. For Capps, it's an average of 8.3 feet, thanks to, well, if you've ever seen his nontraditional (but legal!) delivery, you know why:
Capps' average perceived velocity of 101.7 mph was the only one to top Chapman's 100.8 mph, and that actually made his curveball better too, since off-balance hitters collected just four hits on it in 2015.
FIP, measured on the same scale as ERA, judges a pitcher based on what he can control: Strikeouts, walks, and home runs. Since the birth of the American League in 1901, there have been 26,263 pitcher seasons of 30 innings.
Obviously this is skewed towards recent one-inning relievers, but that's the nature of the game today. Just about no one has done what Capps did last season. Now obviously, 31 innings in 2015, and just over 130 for his career, is hardly enough to say with certainty that Capps belongs in the upper echelon of relievers, particularly when he needs to prove he's over the sore elbow that cost him the end of his season. All the same, you don't get numbers like this by accident.
Whether that turns him into a key piece of a young Marlins 'pen, or a trade candidate waiting to happen -- and we all saw what the Phillies just got for Ken Giles, another 25-year-old flamethrower who came out of seemingly nowhere -- Capps is at least a name you'll remember from now on. A year ago, even that would have been considered a big success.
Mike Petriello is an analyst for MLB.com and the host of the Statcast podcast. He has previously written for ESPN Insider and FanGraphs. This story was not subject to the approval of Major League Baseball or its clubs.