Revisiting Chris Davis’ Troubling Trend

Few players can heat up the way Chris Davis can. Baltimore’s left-handed slugger has homered five times in his last six games, and over the last two weeks has ran a .432 ISO and 183 wRC+. It’s a sufficient number of stretches like this one over the course of a season that leave Davis winding up among the league’s best hitters, as he did in 2013 and 2015.

Few players can get lost the way Davis sometimes can too, though, and certainly few are getting paid more. Before Davis’ current two-week hot stretch began, the $161-million man was barely a league-average hitter, posting a 103 wRC+ over his first 451 plate appearances in the first year of the seven-year contract he signed in the offseason. Even when Davis has struggled to make contact, he’s walked enough to maintain a respectable on-base percentage, and he moves well enough for a slugger to accrue base-running value and avoid being a liability in the field. So, the season as a whole hasn’t been a disaster: he’s projected to finish the year with roughly 3.5 WAR. But the bat’s what earns Davis his money, and when Dan Duquette handed out the largest free-agent contract in franchise history this January, he certainly wasn’t hoping to see it look like this so soon.

And just before Duquette handed out that very contract, our own Jeff Sullivan, writing for FOX Sports, pointed out a troubling trend within Davis’ game, regarding that very bat. Sullivan noted that Davis was on a five-year run of increasing his pull rate, pulling air balls more each year, and pulling ground balls more each year. The culmination of that five-year increase was Davis, last year, ranking in the 99th percentile in pull rate. In other words, he’d become the most pull-happy hitter in baseball. The extra pulled grounders resulted in more shifts, and more outs. The extra pulled air balls presented a potentially worrisome indicator, too. To quote directly from that article:

People say that, as hitters age, they try to become more pull-happy, to squeeze out as much power as possible. That’s not the only explanation, but this could be Davis adopting and embracing an old-player skill. Which isn’t what you want to think about a player who’s been offered a seven-year contract.

In the end, I can’t say much of anything with certainty. I don’t love this trend, but Davis obviously made the pull-hitting thing work just last year. He still has the power to hit the ball out the other way, and maybe next year the trend will suddenly reverse.

“Maybe next year the trend will suddenly reverse.” What follows now is a leaderboard, showing the five largest decreases in pull rate, from last year to this one:

Pull% decrease, qualified hitters, 2015-16

1. Chris Davis, -12.7 percentage points
2. Odubel Herrera, -8.9 points
3. Stephen Vogt, -6.7 points
4. Starling Marte, -5.8 points
5. Chase Headley, -5.3 points

No one’s dropped their pull rate more than Davis, who’s gone from pulling 56% of batted balls in 2015 to 43% of batted balls in 2016. Davis’ drop in pull rate is nearly twice as extreme as the third-most extreme decrease in the league. Where last year he ranked in the 99th percentile in pulled balls, he presently ranks in the 71st — his lowest such mark since his first year in Baltimore, in 2012.

So, that could be viewed as a… good thing? With Davis’ extreme pull rate last season, an already one-dimensional hitter became even moreso, and that outlier trait could be viewed as a 30-year-old embracing an old-player skill. Except, that assumes the drop in pull rate is somehow a function of a decision made by Davis himself — as opposed merely to a sort of regression. While pull rate is certainly an expression of a hitter’s tendencies, it’s unreasonable to expect a player to maintain anything in the 99th percentile, pull rate included. That’s one of the risks of Davis’ approach: for him to duplicate his best seasons, he has to remain an outlier. And almost by definition, that’s not something you can expect.

Here’s another way of expressing the same thing:

That’s Davis’ rolling pull rate during his entire time in Baltimore, spanning five years. He’s coming off a stretch with fewer pulled balls than ever, and that stretch coincided with an awful cold streak. Lately, the pull rate’s gotten back up toward his career norm, and that’s coincided with an awesome hot streak. So it’s good that Davis is pulling the ball more often. His success basically depends on it. But, as the graph illustrates, even Davis is prone to variance.

Finally, to make this all confusing as possible, I want to add one more conflicting data point. Despite the recent uptick in pulled balls coinciding with a recent hot streak, Davis’ production to the pull field is well below his career norm, and here’s a potentially worrisome graph:

It probably doesn’t look super worrisome due to the modesty of the slope, but every year since Davis came to Baltimore, fewer and fewer of his pulled air balls have turned into home runs. When Davis pulled a ball in the air during his breakout 2012, it turned into a home run nearly two-thirds of the time. Each year, that number’s fallen, and this year, “just” over 40% of Davis’ pulled air balls have become homers. That’s still a huge number, it’s just lower than before, and getting lower each year. This is, potentially, an indicator that Davis’ raw power could be slipping? Which is precisely what makes guys become more pull-happy in an effort to squeeze out any last bit of power possible — the “old-player skill” to which Sullivan referred in his January piece on Davis. To be clear: this interpretation is speculation, and nothing more.

One more thing I want to show. A sampling of Davis’ five homers over the last week.

A homer from Saturday:

Dinger from Thursday:

Another Thursday tater:

Davis obviously still possesses enough strength to hit the ball out to all fields. And I understand that this can read as a relatively negative article for a player on such a tear. That wasn’t exactly the intention, that’s just how it wound up. What Chris Davis has been doing lately has been working. What Chris Davis was doing before that, wasn’t. Going extreme to the pull side didn’t look like a super promising trend in the offseason, but when Davis reversed that trend this year, things went south. When he reversed it to the extreme, things went extremely south. Davis is probably at his best when he’s hitting the ball with authority to all fields, though that much can be said for just about anyone.

The potential indicator that Davis’ raw strength could be slipping brings us back to that “old-player skill” phrase, but the good news is that even if it is slipping, it’s slipping from an absurdly high starting point. Chris Davis has been getting back to pulling the ball more lately, and maybe that’s for the best. An old-player skill is only a bad thing when it results in old-player production. These last couple weeks, getting back to the extreme pull side, Chris Davis has looked anything but old.