The Miami Marlins were looking to depend on Steve Cishek during the 2015 season as a closer, but his struggles left them scrambling for replacements to move up the chain of command. A.J. Ramos filled the closer role smoothly, but someone had to take over his setup role spot. That landed squarely in the hands of Carter Capps, a right-handed hard-throwing guy of reasonable interest before the 2015 season. By the time the 2015 season ended for Capps due to a strained right elbow, he became a far more interesting player.
Capps was actually demoted to Triple-A to begin the year despite a strong end-of-season performance last year and consistently decent peripherals throughout his time in Miami. His issues from when he was a member of the Seattle Mariners came down to giving up more home runs than expected, which did not figure to be as much of a problem in the confines of Marlins Park. Capps always missed bats, as he got whiffs on 12.8 percent of all pitches in 2013 with the Mariners and on 13.8 percent of them in his brief stint in 2014.
However, in 2015, something definitely changed, and it was this motion that made all the difference.
That little jump-slide, a move that was ruled legal by MLB early in the season, has turned Capps from a hard-throwing right hander to one of the most unhittable pitchers in baseball. Capps already throws ridiculous gas as it is, as he averaged nearly 99 mph on his fastball based on Brooks Baseball's classifications and exit velocity from hand. But the movement of Capps forward on the mound, even as he is jump/dragging his back foot off of the rubber, allowed him to release that monster fastball at a higher perceived velocity than anyone else in baseball. Grantland's Ben Lindbergh points out that Capps threw a perceived velocity to hitters of 101.1 mph, about 3.5 mph more than the actual velocity measured by MLB's StatCast data. Aroldis Chapman, the Cuban Missile, clocked in at second place at just over 100 mph.
That kind of perceived velocity made Capps's fastball an untouchable weapon. In 2014, Capps was throwing the pitch about 0.4 mph less than he did last season and got nearly a 20 percent whiff rate on it. In 2015, that whiff rate skyrocketed to 35 percent, the kind of whiff rate you might expect from an average or mediocre slider! That still did not beat out Chapman's 41 percent mark on fastballs, but it was darn close. When hitters did make contact, they did square up the ball better overall, with a hard-hit ball rate of 41 percent versus 35 percent last year. It is telling, however, that hitters had to go the opposite way a lot more often than they once did against Capps; this season, only 25 percent of pitches hit off of Capps were pulled this year, which was the second-lowest rate among relievers with 30 or more innings. Hitters simply had a hard time gearing up for that 101+ mph perceived heat.
But it was not just the heater that turned Capps into a potential relief star. He also has a seemingly untouchable slider against right-handers that looked even more untouchable this year. The pitch has a ton of break away from righties, on par with Steve Cishek's slider. However, it gets a lot more swings and misses, perhaps in part because of the fear of the fastball. Last year, it was at a 63 percent whiff rate among pitches swung at. In 2015, it hit a 76 percent whiff rate.
The combination of the two pitches merged to make Capps unstoppable on the mound. Capps had the lowest overall contact rate among relievers with at least 30 innings, down at 53 percent. Only two more relievers, Chapman and Andrew Miller, managed contact rates in the 50 percents. Since Pitch F/X made data fully available at all parks in 2008, Capps has the lowest contact rate and is one of only five player seasons with a rate below 60 percent. If we go back to 2002 using BIS data, Capps trails only Brad Lidge in 2004 in terms of lowest contact rate in our modern times. His contact rate was better than some of the best relief seasons in the history of baseball!
Capps is still relatively new to the majors, especially with his new style. Batters will eventually adjust and bring those numbers back down to earth. Given his delivery and his most recent bout of elbow problems, he could potentially be a ticking time bomb for Tommy John surgery in the future. But for now, he appears to have a complete stranglehold on hitters with his combination of borderline unfair delivery and hard velocity and movement on his normal pitches. He could be the real deal, at least for now.