Wednesday night, in a game against the A’s, the Mariners started James Paxton and received one of the most dominant starts in the franchise’s whole entire history. A couple innings after Paxton was removed, the Mariners lost, and the conversation deteriorated into an argument over bringing in the closer in a non-save situation. Thursday has brought the additional news that Ichiro Suzuki is transitioning into a non-roster advisory role, so it would be easy for Paxton’s start to get lost in the shuffle. It wasn’t the most important story of the game, and the game is no longer the most important story of the day.

But I won’t turn down many opportunities to write about James Paxton. I have the freedom to write what I want. And Paxton wasn’t only good against the A’s. He wasn’t only overwhelming. He was almost genuinely unhittable, collecting 16 strikeouts over the span of seven innings. Paxton issued one single walk, and he allowed a handful of hits. Nobody scored. Of Paxton’s 105 pitches, an incredible 80 of them were strikes. I know that, through the lens of ERA, this year’s Paxton has been modestly disappointing. That ERA misleads, and Wednesday provided a reminder that Paxton is almost as good as it gets. And as he went about setting down the A’s one by one, Paxton followed a pretty simple game plan. It’s one that could hint at even more to come.

Even after Wednesday, the A’s offense ranks third in baseball in wRC+. Against lefties, they rank sixth, and while the A’s might be somewhat strikeout-prone, they’re not the game’s most whiff-happy lineup. Paxton prevented them from doing just about anything. His 16 strikeouts were backed up by nearly twice as many swinging strikes. Where did all of those swinging strikes come from? Brooks Baseball makes it perfectly clear:

Anything stand out to you? That shows Paxton’s entire big-league career, with his most recent start, of course, being furthest to the right. And, Wednesday, Paxton picked up 25 swinging strikes on just his four-seam fastball alone. Not only is that the highest mark of his career — it’s the highest by double digits. Paxton’s never been even close to that successful with his heat, at least as long as you’re thinking about swings and misses, and for further information, we can consult the locations of Paxton’s whiffs from Baseball Savant:

A few low cutters. One low curveball. And then basically a whole bunch of elevated fastballs. Some are more elevated than others, but the majority of those whiffs are in the upper half. Now, you’ve heard about the high fastballs. You know that some pitchers and teams like to throw their fastballs up, to try to change the eye level and counteract all this movement toward swinging for launch angle. What’s interesting about Paxton, and about this Paxton game, is that he hasn’t flirted with high fastballs very much before. It’s not like he’s been Brad Ziegler out there, but Paxton has often aimed for the knees. This plot, also from Brooks Baseball, shows Paxton’s monthly average fastball height. It’s relative height, with 0 representing the vertical middle of the strike zone. I chose to look at this on a monthly basis because it evens out some noise. Conveniently, on the far right, Paxton has started only the one game this May.

Paxton, mostly, has pitched below the vertical middle. And that’s fine — obviously, he’s made it work. Paxton has been a good pitcher. But has he been missing out on something? On Wednesday, he elevated like he hadn’t before, and the A’s just whiffed and whiffed and whiffed. And when you look at Paxton’s history — well, this heat map probably speaks for itself. This represents Paxton ever since he debuted in the majors. You’re seeing whiff rates, by location, against fastballs and only fastballs.

Historically, Paxton’s fastballs have found most of their misses up. That’s not too terribly uncommon. And yet, Paxton hasn’t exactly embraced the high fastball, anyway. This is what makes Wednesday so interesting. I mean, the game is interesting even in isolation, just because of how dominant Paxton was from the beginning to the end. But there’s a chance this could be a watershed. More than ever, it was demonstrated to Paxton how well the high fastball could work for him. Perhaps he might keep it up moving forward. Perhaps James Paxton will only improve.

He does have a cutter, which he likes to throw low. It’s become a good pitch. And the curveball can be fine, as a change of pace. At this point it isn’t anything special. The bread and butter is the heat, and I feel like I’ve waited too long to show you some clips. Let’s make up for that. Here’s a whiff on a two-strike high fastball:

Here’s another whiff on a two-strike high fastball:

Here’s another whiff on a two-strike high fastball:

And here’s a high fastball for a called strike one:

It’s not like Paxton’s fastball needs to live at the letters. It’s a strong pitch in the zone, even when it’s almost mid-thigh. A high fastball for Paxton doesn’t need to be an ultra-high fastball, because his velocity is so good and easy. Paxton is already hard to square up, as he’s constantly putting hitters on the defensive. This is all just talking about a potential way for him to record a few more swinging strikes. There aren’t so many swinging strikes to be found when throwing fastballs at the knees.

James Paxton was dominant Wednesday. He was dominant because his mechanics were clean and easy, but also, he was dominant because he had control of an upper-half fastball. In the past, he hadn’t thrown all that many upper-half fastballs, even though those were mostly the fastballs that recorded the whiffs. Moving forward, Paxton might return to what he was, with Wednesday looking like a one-off. Maybe the game plan identified that the A’s were uniquely vulnerable. Or maybe Wednesday will be something of a turning point. Paxton was already a very good pitcher. That doesn’t mean he didn’t still have room to grow.