Craig Kimbrel has a nasty curveball, too

Sometimes, it’s easy to forget just how good of a pitcher the Red Sox acquired when they traded all those prospects to San Diego for Craig Kimbrel. Put aside your thoughts on the deal for a second; this is a generational talent we’re talking about. Obviously, it’s something we all know. However, I spent a good chunk of last night watching highlight videos of his on Youtube, and I came away thinking he’s the type of player you need to watch regularly to really appreciate how good he is. With that being said, just looking at the numbers do tell a pretty good story.

Exactly how he is so effective is relatively straight forward. Tim Britton had an interesting look at how he became the pitcher we know today. Specifically, it shows how he was able to develop his overpowering fastball that he uses to muscle past every hitter in his path. Most of the attention throughout his career has been paid to his fastball, which makes sense because he regularly pumps it close to 100 mph. Kimbrel’s not a one-pitch pitcher, though. Very few pitchers not named Mariano Rivera can survive like that.

To go with that overpowering, near-triple-digit fastball is a dominant breaking ball. It’s not entirely clear what he’s throwing, and it’s been called many things over the years. Whether it’s a slider, a knuckle curve or just a straight-up curveball, it’s been a perfect compliment to his fastball. For the rest of this post, we’ll be referring to it as a curveball just to make things easier.

Looking at the numbers, it’s clear that the curveball is purely a complimentary pitch for Kimbrel, as there’s a roughly 70/30 split between his fastball and breaking ball. One way to know that this has been a successful combination for a long time is the fact that he hasn’t significantly changed that distribution in any year of his career. In fact, that split is essentially the same for any count, excepting three-ball counts. It also doesn’t change based on the handedness of the batter at the plate. It’s an 87 mph pitch with sick movement, which is basically impossible to make good contact with if you’re sitting on a 100 mph fastball.

That’s easy to say, of course, so let’s look at a few numbers to illustrate how effective this pitch has been over the years. The most important thing for any part of Kimbrel’s game is getting swings and misses, and his curveball does that in saves. To wit, 54 percent of the swings against the pitch over his career have resulted in a whiff, per Brooks Baseball. That number climbed to a career-high 58 percent last season, showing that he could still be improving at this stage of his career. As you can see in the following zone plot, the majority of the whiffs come on pitches down and out of the zone to Kimbrel’s glove side.

Beyond the whiff-rates, Fangraphs has numbers that put a value on every individual pitch for every pitcher. It’s not my favorite stat, especially over single seasons, but it’s useful for quick-and-easy research and is generally telling at the extremes. They’ve counted this pitch as a curveball every year since 2012. Since that season began, Kimbrel’s curveball has accrued the sixth most value of any curveball in baseball. No relievers rank higher on that leaderboard, with David Robertson in 15th place as the second-best curveball out of the bullpen.

Numbers are great, but as I said before he’s the kind of pitcher who can be better appreciated from watching him do his thing. So, let’s do that with a few gifs of his curveballs making major-league players look silly.

This one is from way back in 2012, in Kimbrel’s second appearance in the All-Star game. For context, he started this at bat against Asdrubal Cabrera with two straight fastballs before completely freezing him with a curveball on the black. As I said above, it’s really hard to adjust to that pitch when you’re looking for the heat, so get used to batters looking like Cabrera on that pitch.

This next one comes from 2014 and pins him against one of the best hitters in the league in Troy Tulowitzki, in Coors no less. None of that mattered, as once again he made his opponent look silly. This time, we see what we’re talking about with those whiffs shown in the zone plot above. The curveball drops down and out of the zone, but not before Tulo decides to swing. At that point, it’s too late for him to do anything.

Finally, we have what might be my favorite gif of this series. In practice, it’s not much different front his face-off with Tulowitzki. This time, however, there’s a little more break on the pitch. More importantly, it happened last season, which is perceived as something of a down-year for Kimbrel. This one is mostly for people who think there’s some kind of decline here. One pitch will never tell a story, but it can show that he can still clearly command his nasty curveball.

Over the season, Kimbrel is going to get a lot of attention for his fastball, which he should. He’ll throw it about 70 percent of the time in the high-90’s and get countless strikeouts with it. The curveball is what really makes him go, though. The numbers show it keeps hitters off-balance and results in a lot of strikeouts, and the gifs show how aesthetically pleasing it is. I am so excited to watch Craig Kimbrel this year.

Gifs were taken from Kimbrel highlight videos from 2012, 2014 and 2015.