Carter Capps allowed a three-run single on Tuesday. That’s both pretty bad and pretty weird. Three-run singles might be a post topic of their own, but the most interesting thing didn’t have anything to do with the play result. Before Xander Bogaerts ever swung the bat, Capps threw a fastball, and I’ll excerpt conveniently from an MLB.com entry by Ian Browne:

Bogaerts hung in on a pitch that had a perceived velocity of 105.55 mph, the highest number of any pitch in the Major Leagues this season, according to Statcast™. The pitch looked that fast to Bogaerts, thanks to an extension of 9.5 feet by Capps.

This sounds complicated, but it’s simple to understand. Not a whole lot of time passed between Capps releasing the ball and the ball arriving around home plate. That’s all perceived velocity is — a kind of measure of flight time. According to Statcast, this year, no pitch has had a smaller flight time than the one Bogaerts drilled for a hit. That’s remarkable, on Bogaerts’ part, and that’s remarkable, on Capps’ part. Capps’ part, we’re becoming more familiar with.

This is a post about unhittability, and all I’ve talked about so far is a hit. That’s probably bad structure, but the pitch that Bogaerts hit for a single in the first place helps get us to where we’re going. Early on, there would’ve been little reason for Carter Capps to be on your radar. He was an intriguing young middle reliever, but I’m a professional baseball writer, and I’ve never heard of a number of intriguing young middle relievers. Then Capps was dealt for Logan Morrison, and maybe you noticed. Then April happened, and, you noticed.

April brought us the controversy about Capps’ delivery. April made Capps a borderline household name, at least among those households that pay a decent amount of attention to baseball. To refresh your memory:

Here’s a clip from the Braves’ broadcast, drawing arrows to correspond to Capps’ estimated release point:

If you recall, Capps had some issues with his delivery in the minors. A couple times in a row, an umpire declared he was throwing illegal pitches, and Capps and the Marlins sought league clarification. What Capps was told was that he was okay, so long as he dragged his back foot instead of lifting it in the air. As several have noted, there are parallels between Capps’ delivery and Jordan Walden’s. Capps hasn’t been in any trouble since, with the league basically signing off on this. And make no mistake, this is kind of new. Capps always had an exaggerated delivery, in college and with the Mariners, but it didn’t look quite like the above.

Capps jumps. If you look at the second .gif above, not only do you see him jumping off the rubber, but you see a mark on the mound right around where his back foot lands on the dirt. That mark is the result of pressure, suggesting that Capps is pushing off some, after coming back down. It doesn’t seem like a legal pitch, but MLB hasn’t spoken up yet, and it would be weird for them to suddenly start. So if this is ever going to be addressed, it won’t be until at least after this season.

And why would Capps jump forward? It’s deceptive, and it gets him closer to the plate. So it reduces the average flight time of his pitches, because said pitches have less distance to cover between hand and glove, or hand and bat. Think of it as Capps effectively lengthening his stride, or his arm. Not long ago, Ben Lindbergh dug into the Statcast information that was available to him. What Carter Capps doesn’t do is throw his fastball as hard as Aroldis Chapman. But Capps’ fastball spends less time in the air than Chapman’s, because of that delivery. So in terms of perceived fastball velocity, Capps was the king. He threw one of those king-like pitches to Xander Bogaerts. The pitch got hit, but even kings make mistakes.

Little of what’s above is actually new. We’ve known for months that Capps is an odd bird. And we’ve known for at least weeks that he gets a substantial velocity boost from the way that he throws. At least, as far as the hitters are concerned. So, already, Capps was curious. The only thing left was to monitor his results. Now those results are getting out of hand. Tuesday aside, Capps looks like he’s the most unhittable pitcher in baseball. It’s been only a short amount of time, but the case is convincing.

Set a pathetically low minimum of 20 innings pitched. 20 innings are 20 innings, but it’s better than 10 or 0 innings, and we’re just trying to learn, here. The current leaders in strikeout rate:

Cool. Now, relatedly, the current leaders in lowest contact rates allowed:

Carter Capps, 50% contact Andrew Miller, 57% Craig Kimbrel, 61%

What gets me are both the realities of the leads, and the amounts by which Capps is in front of second place. In both categories, it’s Capps by a landslide. Now let’s take it back to 2002. Only 2014 Chapman and 2012 Kimbrel have finished with higher strikeout rates than Capps has at the moment. And no one has finished with a lower contact rate. Capps has generated more swings and misses than he has swings and contacts. Making contact against him has been something worse than a coin flip. That’s a silly statistic, but Capps is a silly pitcher.

Here’s a big table of some pitch data. Baseball-Reference has such information stretching back to 1988, so let’s make use of it. Here are each season’s lowest contact rates allowed, given a minimum of 20 innings. I shouldn’t need to remind you that, of course, Capps’ 2015 season isn’t complete. This is just for some reference. There are slight differences in reported contact rates between Baseball-Reference and FanGraphs, but we can live with that.

Capps has the smallest rate in the table, followed by 2004 Lidge, who’s behind by five percentage points. You find some flukes and some dominant long-term relievers. That’s the way that it goes, because relievers are unreliable, and they can get hurt. But Capps, for now, is healthy. And Capps, unlike some of the pitchers above, throws two-thirds of his pitches for strikes. He’s not just forcing hitters to chase sliders out of the zone. Capps isn’t quite that one-dimensional.

But he does have a breaking ball, and the numbers are stupid. Batters have swung at it 59 times. Batters have missed it 47 times. It’s like a page out of the book on Aroldis Chapman’s changeup, where Capps’ breaking ball is dangerous both because it’s a good breaking ball, and because it isn’t his fastball. Against Capps, hitters have to gear up for 98, which looks like 101. Then he throws this slurvy thing at 84. It’s difficult to protect against them both, and when there are two strikes, Capps throws both pitches in roughly equal amounts.

Unsurprisingly, Capps is a difficult pitcher to pull the ball against. And he’s clearly achieving a new level, having become more comfortable with this exaggerated throwing motion. In three previous years in the majors, Capps’ strikeout rate topped out at 29%. His contact rate was never lower than 72%. He’s trimmed his out-of-zone contact rate by more than half. It doesn’t seem like someone should be able to throw a baseball quickly and accurately with Capps’ motion, but he’s got it mastered, having been helped by the Marlins, and with that motion and two pitches, Capps doesn’t need anything else. Aside, that is, from assurance that this motion won’t soon become illegal.

And that’s something baseball might well have to deal with. It would be one thing if Capps were just good, like Walden has just been good. But to this point, Capps has mostly made a mockery of his opponents, potentially motivating other, fringy relievers to try to mimic the same motion. It would be difficult to argue the delivery isn’t giving Capps an advantage, and baseball needs to think long and hard about whether it wants that advantage to be available to other guys. Not that it’s an easy thing to copy, but it could be copied, and baseball probably doesn’t want all of its pitchers looking like this. How many would it allow? Right now the game is comfortable with two, but it might not be so comfortable with, say, five, or 10, or 100. This is far from a league priority, but right now it’s kind of like a loophole, and there are careers on the line for hundreds of pitchers just looking for a chance.

Carter Capps has turned himself into something absurdly good. It’s interesting to wonder if, as a consequence, Capps is just doing himself future harm. Yet, all that is right now is speculation. Capps’ dominance, meanwhile, is reality. It’s a pretty good way to live in the moment.