It’s not so bad in the bigger picture. Since the start of last season, Chris Davis has been worth more than seven wins, equal on our pages to the contribution from Jayson Werth. That’s not quite superstar-level, but that’s pretty damned good, and you’d think just based on that that the Orioles are pleased with their slugging first baseman. But since the start of this season, of course, Davis has looked like a different player. Or, Davis has looked like an identical player, but he’s performed like a different player. He’s basically tied in WAR with Garrett Jones, and Mike Petriello tells me he recently heard an Orioles fan complaining about Davis pinch-hitting for Delmon Young. Things are weird.

The Orioles, as a whole, are weird. They’re right where they want to be, in first place, but they’re in first having gotten very little out of Davis. They’re in first having gotten very little out of the injured Matt Wieters. They’re in first having only recently started to get production out of Manny Machado. They’re in first having gotten very little out of Ubaldo Jimenez. In order to hang on, the Orioles are probably going to need their most talented players to step up down the stretch. You can count Davis among them, but he’ll have to shake off a season-long slump, a slump we can isolate to one particular part of his game.

Last year was Davis’ breakthrough, when he had a year that ordinarily would’ve put him higher in the running for the league MVP. It wouldn’t be fair to say he closed up all the holes in his swing. His 69% contact rate was right on his career average. But while he didn’t cut his strikeouts, he did increase his walks, and he made a lot more of the balls he made contact with. Davis hit more pitches into the air, and he hit more of those pitches over the fence. He also ripped off a high BABIP, which is a credit to his ability to hit the crap out of the ball when he hits the ball. Davis is a player who’s historically blended good BABIP with good power, and last season everything came together for him.

Naturally, there were adjustments, and Davis did worse in the second half than he did in the first. Naturally, there were more adjustments, and Davis today is slugging .390. His strikeouts look more or less normal. The walks are still there. Davis has been a little more selective. But his quality of contact has eroded. More of his contact has yielded foul balls, and less of his contact has yielded hits. His rate of fastballs seen has dipped, to 2012 levels, but you get the sense that Davis is just caught in between. And if you dig deeper, you can see that it’s Davis’ greatest strength from 2013 that’s betraying him now.

Probably, you’re familiar with our pitch values, available on player pages and the leaderboards. For hitters, it’s a measure of productivity against pitch types. It’s all based on linear weights, and here’s what Davis is showing. But let’s put some numbers together. Let’s combine fastballs and cutters into fast pitches, and let’s combine everything else into offspeed pitches. Now let’s put the resulting values over a 100-pitch denominator. I’ll explain more after this table, but, here’s a table:

Season wFast/C wOff/C 2008-2011 -0.3 0.4 2012 1.0 0.2 2013 1.7 3.1 2014 1.4 -1.8

How to read that: in 2013, Davis was 1.7 runs better than average per 100 fast pitches. He was 3.1 runs better than average per 100 offspeed pitches. Those are extraordinary marks, if you consider how many pitches a guy tends to see each season. You can see how Davis took a step forward in 2012 — he shortened up his swing a bit and made himself better able to handle the heat. The next year, Davis carried over his improvements, and also beat the living crap out of offspeed pitches. He was never bad against the slower stuff, but last season he feasted. This year, it’s half of a completely different story. Davis has been just about the same guy against fastballs. Yet against non-fastballs, he’s had all kinds of problems, to the tune of a decline of about five runs per 100 pitches.

Quick and easy: Davis can still handle a fastball. He’s seeing fewer of them, though, as he’s getting pitched more carefully, and he’s been a mess against the rest of everyone’s repertoire.

Here’s a table of slugging percentage on contact, which tells an identical story:

Season SLG on Contact, Fast SLG on Contact, Off 2008-2011 0.642 0.729 2012 0.739 0.752 2013 0.812 1.154 2014 0.762 0.495

When Davis put offspeed pitches in play a year ago, he hit 34% of them on the ground. This year, he’s hit 44% of them on the ground. His actual contact rate isn’t any different, but where last year 50% of his contact yielded foul balls, this year he’s at 56%. Davis, in short, hasn’t been putting good swings on slower pitches, and while you’re free to theorize on why that might be, I’m just here to show you the data. This is what’s been happening. This is what Davis and the Orioles need to not happen.

Here’s an extended quote from April, before anyone knew how deep this slump would go:

“I think a lot of it is patience which, as aggressive as I am in the box, it’s hard,” Davis said. “But I think it’s going to pay off towards the end of the season. Last year, after the All-Star break, guys really made an adjustment and started to be a lot more careful in how they pitched me, and that’s continued this year. Guys go up there and throw me four straight change-ups or four straight split-fingers. It’s kind of a coin flip. So, that’s good. See as many pitches as I can early, and hopefully once it starts to heat up, the balls start flying again. “I think they are locating a little better in. I think, last year, a lot of times, it was just for show to try to get me off the pitch away and try to move my feet a little bit. This year, they are locating a little better. They have the advantage, man. When it’s cold, you are trying to get the head out. I’ve rolled over a few pitches that were inside that I couldn’t quite stay through. It’s coming along. I said last year I wish I could bottle up the feeling I had, I’d be a really rich man if I could sell that. But, it’s part of it.”

On May 23, Davis’ OPS topped out at .892. He wasn’t slumping at all! Since then, he’s hit .157 and slugged .323 over more than 200 trips to the plate. Pitchers have shifted away — where for two months they threw 39% of pitches to Davis inside, that’s dropped to 23%. Earlier in the year, Davis wasn’t hitting offspeed pitches. More recently in the year, Davis hasn’t hit offspeed pitches. Granted, for the last little stretch he hasn’t hit fastballs either, but that skill’s mostly been with him. It’s been about the mid-swing adjustment to a different type of pitch. That’s where Davis hasn’t been his most recent old self, or even his less recent old self.

It’s not about a specific type of offspeed pitch, or about a specific location. There aren’t dramatic differences in how Davis has been pitched overall. But he feels like he’s been pitched differently in each individual plate appearance, and when you’re looking at the overall picture you don’t really get much of an idea of the sequencing. Obviously, Davis is badly off-balance. Obviously, opposing pitchers are keeping him way off their slower stuff, generating missed swings or bad contact. Obviously, Davis is facing a different challenge. With a season like Davis’ 2013, the easy thing to say is it was a career year, driven by noise and a small sample. I prefer to think it was driven also by talent, but now pitchers are working Davis differently and forcing him to repeat his performance differently, in turn. Chris Davis adjusted to make himself good once. The best players never stop adjusting.