I’m going to be honest, I feel a bit dirty writing this post. We’re now on year five of Craig Kimbrel being impossibly good. For four years he’s clearly been the best reliever in baseball and, frankly, it’s one of the better stretches of relief pitching we’ve seen in recent history. Yet, this is the first post on FanGraphs this year where he is the subject, and it’s about him making a mistake. Which, really, just reinforces how good Craig Kimbrel is. He’s so good that when he makes a mistake, it becomes news. On Wednesday, Kimbrel made a new kind of mistake.



Though there hasn’t been a post this season in which Kimbrel was the main subject, that’s not to say he hasn’t been mentioned. His name was invoked in a post by Jeff Sullivan earlier this year on baseball’s most and least homerable pitches. For the purposes of setting up today’s post, I’d like to recreate a table that ol’ Jeff published:

You now know what the mistake is that Kimbrel made. One of those things used to stand out from the others. Now, it’s just another low number. In case you still need help figuring it out, I’ll post the tweet that got the ball rolling on this post:

Just realized — Bryce Harper’s homer against Kimbrel a few days ago was the first EVER homer off a Kimbrel curveball http://t.co/dpSlLOU514 — Dan Rozenson (@SixToolPlayer) September 15, 2014

You can click that link to learn a little more about Kimbrel’s history with the curveball, or you can just keep reading, as I am about to explain it to you.

The pitch Kimbrel throws the most is a fastball. He throws it about 70% of the time. The other 30% of the time, he throws a bendy pitch. From 2010-2012, it was classified as a slider. Now, the classification systems are calling it a knuckle curve. The disagreement on what to call it is fitting, because it is unlike any other pitch in baseball.

Since 2008, when PITCHf/x began collecting pitch data, 157 pitchers have thrown at least 1,000 curveballs. At 87mph, Kimbrel’s is the fastest, by more than 3.5mph. At 53%, Kimbrel’s gets the most whiffs, by more than 6%. And at 9%, Kimbrel’s generates the least amount of fly balls, which leads us to the big point:

Kimbrel has thrown 1,411 bendy pitches in his career. Of those 1,411 pitches, 314 have been swinging strikes. Just 128 have resulted in balls in play. Of those 128 balls in play, Kimbrel has allowed 38 hits. Of those 38 hits, 36 have been singles. One was a double. None were triples. And, as of Wednesday, one is a home run.

In Kimbrel, clearly, you have an extraordinary talent. In Bryce Harper, you have another extraordinary talent. Sometimes, when two extraordinary talents collide, you get an extraordinary result.

History:

My first thought was “I wonder if Kimbrel knew?” The Braves announcers picked up on it pretty quickly. Something tells me Kimbrel knew:

It’s impossible to quantify exactly how good or bad an individual pitch is, but this certainly wasn’t Kimbrel’s best curve. By results, it’s the worst he’s ever thrown. By location, it doesn’t get much better:

But it’s not like Kimbrel throwing a curve middle-middle is a recipe for disaster. He’s thrown a curve right down the pipe like this 71 times in his career and they’ve only resulted in 19 balls in play. Of those 19 balls in play, 18 (!) were either ground balls or popups. Even when hitters get Kimbrel’s breaking ball right down the middle, they don’t even come close to doing damage with it. Oh, and here’s the other “fly ball,” from way back in 2011:

So how did this happen? Perhaps past history between Kimbrel and Harper can clue us in. Being in the same division, this wasn’t the first time Kimbrel and Harper had faced each other. Being a guy who throws a breaking ball 30% of the time, it wasn’t the first time Harper had seen Kimbrel’s breaking ball. It wasn’t even the first time he had seen it in the at-bat. That’s my way of segueing into the pitches leading up to the unprecedented dinger:

Kimbrel starts Harper off with a 96mph fastball, away, and Harper takes it for strike one. Nothing too extraordinary about this, besides maybe the amount of movement on Kimbrel’s fastball and the pinpoint command.

Kimbrel comes back with a breaking ball that’s almost in the dirt. Harper thinks about swinging, but wisely lays off. This pitch barely resembles the pitch he would eventually hit for a dinger, but now he’s seen the curve, and that’s what matters.

Now we see our first clue. Harper is waiting on the breaking ball and he gets it. But as we’ve previously outlined, that usually doesn’t matter against Kimbrel’s curve, so Harper swings through it.

After this pitch, Harper turns to Braves catcher Christian Bethancourt, smiles and says something. The camera only catches the last couple words of the exchange, but on first glance it looks like he says “so far.” I would love to believe that he told him, “Throw me a curve again and I will hit it so far,” but it’s just as likely that he said “Hitting that pitch is so hard,” or, “After my last speeding ticket, I have no car.” We’ll never know.

Now, with two strikes on him, Harper is still thinking curveball. He gets a 98mph fastball away, and does enough to foul it off and keep the at-bat alive. That he appeared to still be waiting on a curve is clue number two.

Still ahead of the hitter, Kimbrel comes back with a low fastball to change eye levels, and Harper lays off, probably still looking for a curve. He got it on the very next pitch, and did something that had never been done before.

I looked back through the rest of the history between Harper and Kimbrel’s curve, hoping to find anything else that might have led to this, but there wasn’t much. I was hoping maybe Harper had hit a deep foul ball that just missed being a homer or maybe hit one straight back. I was hoping maybe Harper was one of the seven people to ever hit Kimbrel’s curve for a fly ball and that it was sent to the warning track. Not the case. The homer can maybe be explained by the fact that Harper appeared to be sitting on a breaking ball for the last few pitches of the at-bat, but for the most part, it’s unexplainable.

The home run doesn’t change much. A streak is over, but Kimbrel is still the most dominant pitcher in baseball and his curveball is still the hardest pitch to take deep. He will go right back to punishing hitters and Harper will go right back to doing Harper things. Baseball is a game of failure, and for more than four years, Kimbrel has been beating the system. Craig Kimbrel might have thought he could fool baseball forever, but this goes to serve as a reminder that baseball always wins.