We’ve had fun, but this might be the last post I ever write about opposing pitchers trying to work Mike Trout upstairs with good heat. It’s not that I’m tired of it. I didn’t think I could ever grow tired of it. For me, it might’ve been the most interesting single thing in baseball, the game’s greatest player having such an obvious vulnerability. How often do we really get to talk about that kind of stuff? No, I’m not saying this because I’m tired of the subject. I’m saying this because it might not be a subject anymore.

I can’t imagine you need background. Everyone knows what was going on. Everyone saw what the Royals did to Mike Trout in last year’s ALDS. Trout’s strikeouts went up because teams realized they could throw him fastballs upstairs. OK, this, we’re all familiar with. It was probably unrealistic to expect Trout to make an adjustment last year on the fly. He’d need an offseason to work out how he wanted to respond. I think we’ve now seen his response. That glaring, obvious weakness? It’s completely disappeared.

Trout, of course, was asked about this from time to time. It only made sense; there were no other weaknesses to address. People had to ask him about something. When asked what he was going to do about the strikeouts, and about the fastballs, Trout usually said that the goal was to lay off of the pitches. Trout would explain most of those fastballs were balls out of the zone, so he’d just have to be patient. Reasonable enough, but, interestingly, we don’t see much in the data. At this point, Trout’s swing rates haven’t meaningfully budged:

As a regular, he’s gone after roughly two of every five high fastballs. He’s gone after roughly two of every five high, inside fastballs. There’s no change between Trout’s 2014 numbers and his 2015 numbers. No change here, I mean.

But swing rate is only one measure. It’s far more interesting to look at what the swings have accomplished. You want to see differences? Here are some differences.

This time, we’re looking at contact rate, or contact divided by swings. You see how the numbers were low last season. You see how, this season, they’ve shot up. Against high fastballs, Trout’s contact rate has improved by 15 percentage points. Against high, inside fastballs, it’s improved by 15 percentage points. Last season, Trout swung through about 120 high fastballs. This season, through Monday’s numbers, he’s swung through nine. Because it’s early, you don’t want to take these numbers to reflect Trout’s true talent, but because this is contact rate, which normalizes itself pretty fast, you take notice. It’s a pretty huge step forward.

And, naturally, there’s contact, and there’s good contact. A very rough measure:

That’s a difficult graph to argue with. Looking at slugging percentage by pitch type and location isn’t the cleanest thing to do in the world, but it can be useful, especially when it shows differences this enormous. A year ago, Trout bottomed out when dealing with high heat. He did worse than he’d done before, as his game continued to evolve. It’s still evolving. Right now, Trout ranks tied for ninth in the league in slugging percentage against high fastballs. The samples are fairly small, but Trout didn’t do anything close to this in 2014.

We could use some game visuals. Trout fighting off a high, inside fastball:

Trout hitting a high, inside fastball better than that:

Trout clobbering a high, inside fastball, albeit for a long out:

And here’s a dinger against a high, not-inside fastball. It’s almost exactly what the catcher signaled for:

Mike Trout knew what the problem was. Everyone knew what the problem was, and since everyone knew, that meant the competition knew, and that meant the competition would keep on trying to exploit Trout’s weakness until or unless he forced them to stop. Trout needed to do something, and since a good number of those high fastballs are actually potential called strikes, he couldn’t just make a habit of letting them go by. He had to adjust, so that he could do some damage. It would certainly appear the adjustment’s been made. If there’s still an opening up there, it’s tiny. Trout’s prepared for the pitch that so frustrated him for all of a season.

As the theory goes, you can’t fix one weakness without creating another. In more baseball-specific terms, if Trout is more focused on punishing high fastballs, he might’ve become increasingly vulnerable somewhere else. That much seems fairly intuitive. It’s worth noting that, while Trout is running a career-best slugging percentage against inside pitches, he’s at a four-year low against outside pitches. Maybe he’s concentrating so hard on the inner half that he can be exposed on the other edge. But that much still has to be proven. For the moment, I don’t know where Mike Trout is vulnerable. I did, we all did, Trout did, and it was fascinating, but now it seems the hole’s been closed, and I don’t see another hole. I don’t have the damnedest idea of how you’re supposed to pitch to Mike Trout these days. Having to do that probably sucks.

Mike Trout and the high fastball. What a chapter it was. Now it’s time for the next one. This is already one hell of a story.