Sometimes, I feel like I have to set these things up. This isn’t one of those times. The other day, Bryce Harper batted against Aroldis Chapman. Who wouldn’t want to examine that plate appearance in detail? We’re talking about the game’s premier one-inning pitcher, a guy who does something that might never have been done before, and then you’ve got the hottest hitter on the planet, a guy whose at-bats are worth setting alerts for if you’re not already tuned the hell in. Yeah, they’ve matched up before. Yeah, Chapman struck Harper out all three times, on a combined 10 pitches. That was that Bryce Harper. This is this Bryce Harper. Or, as you might know him, Bryce Harper.

The evening: Friday, May 29. The setting: nobody cares. This is about the individuals, not the circumstance, and while the leverage could’ve been higher, the game was close enough everyone was trying their hardest. This was about something other than deciding the score. This was arguably the game’s most watchable hitter and arguably the game’s most watchable pitcher. So you know they had to combine for a watchable matchup.

Pitch No. 1

Just your standard triple-digit fastball at the letters. Hell of a way to introduce yourself to someone. But it wasn’t just a fastball at the letters — it was a fastball at the letters, that Harper swung at. Now, Harper does swing at the first pitch fairly often. And Chapman doesn’t have an unusually low first-pitch-swing rate, himself. But I can’t imagine putting myself in that situation. You’re a left-handed batter, and you’re standing in against someone you see once a year, and he throws 100 with the flu. Who has the balls to try to hit the first pitch? And Harper took a good and mighty cut. At least, that’s what they said, because he didn’t embarrass himself flailing. And he didn’t make no contact. Some guys get their timing by watching. Harper gets his timing by swinging.

The previous batter, incidentally, struck out swinging at consecutive high fastballs. That’s what Chapman does. Maybe Harper thought he could get ahead of the at-bat. Also, I want to point something out. From earlier in the game, against Anthony DeSclafani, who has a pretty good fastball himself:

Look at Harper’s right leg. It’s up, like normal. You know about his aggressive leg kick. Now look at the same leg as Harper sees the first pitch from Chapman:

The kick’s not totally gone, but it’s nearly eliminated, with Harper instead putting his toe down and keeping his heel up. It’s all in the interest of trying to simplify and be quicker to the ball. With his regular swing mechanics, Harper might not be able to connect. This way, he might buy himself milliseconds. For a hitter, few things are more precious than extra milliseconds.

Harper, in the playoffs, used his regular swing mechanics against the flame-throwing Hunter Strickland.

Pitch No. 2

Here we have a not-very-good elevated slider, but it’s too elevated to really do anything with, and plus, with Chapman and his margin of error, there might not be any such thing as a bad slider. There are just better sliders and worse sliders. Harper ends up sort of fighting the pitch off. He uses the same muted right-leg mechanics. If you break it down frame by frame, you see evidence that Harper got his foot down a split-second earlier than on the first pitch, which would’ve just been a response to finding timing, having seen a pitch go by. This is the danger of those other pitches. With Chapman, hitters get so geared up for the impossible velocity, they can end up in front of ordinary velocity. After 101, 91 looks like 71. (This is an exaggeration.)

Pitch No. 3

And, why not go back to the well? Harper swung at one high fastball he was never going to hit. Then he swung at a high slider he was never going to hit. So why not go for the letters again? Harper recognized this one — it’s like he was expecting the high fastball. Which, granted, isn’t the toughest thing to see coming given the circumstances. The slider had just missed badly. Wouldn’t want to risk a miss again at 0-and-2. The heat’s there; Chapman trusts the heat. On the other hand, bases empty, three-run game. Lots of wiggle room. The argument for a slider here is, what’s the harm, really? The argument for a fastball is, this is Bryce Harper, and testosterone comes into play. As a pitcher, you want to get rid of him. Chapman had lots of count to play with. Just had to put one high enough the only downside would be a ball. Based on the catcher’s body language, he knew exactly where this pitch was going to go. Imagine looking that casual, catching Aroldis Chapman.

Pitch No. 4

By showing the pitches right away, it kind of ruins the surprise, but this was a fastball that didn’t get up enough, or that didn’t hug the outside edge enough. You pick. Whatever the case, Harper hit the ball back up the middle, and maybe that’s when you notice the little “102” reading. That’s why you don’t want to be too critical about the pitch location — this was a fastball at 102 miles per hour. Actually, a few tenths above that, even. Over Chapman’s career, when hitters have swung at fastballs at least 102 miles per hour, they’ve whiffed more than 40% of the time. At that speed, any fastball is a good fastball. Harper just caught up to it, enough. He didn’t even hit it the other way.

Chapman thought the heat would suffice. The first signal was for a changeup.

We don’t know why he shook it off. We could come up with a million reasons. Maybe it was about ego. Maybe it was about trying to think two steps ahead. Maybe it’s just that, when you’re Aroldis Chapman, and you have your fastball, sometimes you wonder why you even bother with anything else. It’s as close to unhittable as any pitch in the game. For all I know, it’s the most famous pitch in the world.

Tweeted the creator of Baseball Savant:

Bryce Harper’s base hit last night vs Aroldis Chapman’s 102.2 MPH fastball was the hardest pitch in PITCHfx era anyone has gotten a hit on. — Daren Willman (@darenw) May 30, 2015

That’s not a totally true fact. It’s true for the regular season, but in October 2010, this happened:

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PITCHf/x put that one at 103.5. Without question, a faster pitch than the one hit by Harper. But there’s no point in dwelling on that. Even the 50th-fastest pitch struck for a hit is a blessing. At those velocities, the primary goal for any hitter is to survive long enough to see another sleep. And also, Carlos Ruiz’s double looks almost accidental. It’s like he put that bat out there, and the ball did the rest of the work. Harper went back through the box. It’s something. His advice for hitting Chapman, after the game:

How do you hit a 102-mph fastball? “Close your eyes and swing,” Nationals outfielder Bryce Harper said.

It’s funny Harper should say that. His eyes were wide open.

And he missed squaring the ball up by that much. Not that Harper isn’t more than happy to take the single. But you look at that image, and then you can mentally move the baseball or the bat just a matter of millimeters. Suddenly, instead of a grounder through the middle, you have a line drive. You have a fly ball. You might have a home run.

All because Harper found his timing, and didn’t try to match power with power. This is a very much non-Harper-like follow-through:

You can picture how Harper usually finishes. That’s not it. You can build a maturity narrative around this if you want. Or you can stop short of that and just recognize that Harper made an adjustment because he didn’t want to humiliate himself. Avoiding humiliation is a powerful motivator.

Ultimately, Chapman got a taste of his own medicine — 102 out, 103 back. And Chapman, like many of the hitters he pitches to, couldn’t catch up to the speed.

Noted the Reds’ broadcast as Harper removed his batting gloves at first:

Jeff Brantley: I think if you’re a left-handed batter facing Chapman in this kind of situation, you gotta reach down deep in your belly to hang in there. Thom Brennaman: No doubt about it. That’s pretty impressive.

What you can’t get from the text is Brennaman’s tone. He didn’t sound awestruck. He didn’t even sound just matter-of-fact. There was resignation in his voice. Surrender. A very much reluctant admission that Harper had faced the best, and Harper was better. In that moment, Brennaman conceded that maybe Bryce Harper just can’t be stopped. He’s not the only one who’s thinking it. He’s not the only one surrendering.