Adam Eaton Is Up to Something
Pardon me; I don’t mean to interrupt your afternoon. If you’re here, though, you might well be a bit curious about Adam Eaton. Which is good, because I am, too! To get started, you know those player caps we have on most pages? The profiles and quick opinions, I mean, written by various FanGraphs authors. They’re written during the winter, providing brief player analysis, and here’s a link to Adam Eaton’s page. I’m going to pull a little excerpt. This isn’t intended to pick on Chris Cwik. Anyone would’ve written the following.
Since Eaton isn’t going to add any pop, his performance will likely be based on the guys behind him.
Made total sense at the time. Eaton is a little dude, with an extended track record of hitting groundballs. Last year, as an everyday player, Eaton was literally out-homered by Ben Revere. He went deep just the once, and so he was seemingly easy to project. Speed and contact. Decent number of walks. We all knew what Adam Eaton was, up until we didn’t. This season, Eaton’s already knocked nine dingers. Put another way, he’s tied with Adrian Beltre. Chase Headley and Jason Heyward, too. Adam Eaton wasn’t going to add any pop. Adam Eaton added a lot of pop.
The initial Adam Eaton story this year was that he got off to a dreadful start. He’s fully recovered, and that would be something on its own, but now there’s something more. As noted, Eaton has nine home runs, after having previously hit a total of six in the majors. And they haven’t necessarily come out of nowhere. I mean, when you just scan his record, they come out of nowhere, but they’re accompanied by something else. Eaton, before, has been a rather extreme groundball hitter. Eaton, at the start of this year, looked like a rather extreme groundball hitter. Here’s a graph for you.
We’re looking at Eaton’s entire career, in 30-game chunks. I didn’t choose 30 for any particular reason; it just felt good enough. There’s not really any hiding the trend. Throughout, for years, Eaton mostly kept the rolling rate at or above 50%. Only more recently has it started to drop. It’s dropped fast. Over his last 30 games, Eaton’s hit about one-in-three grounders. The Eaton we used to know came in north of one-in-two.
Grounder rate, of course, is one of those things that usually doesn’t change much unless something else has been changed. Grounders are more or less built into a hitter’s identity. The batted-ball profile comes out of the swing, affected only in small part by the opponents. As a neat little example, here’s a table, showing last years’ top 10 highest grounder rates by guys who’ve also played regularly since this year’s All-Star break. The break is an arbitrary cutoff, but it made the analysis really easy. Look at what the table tells you.
| Name | 2014 GB% | 2015 2nd Half GB% |
|---|---|---|
| Ben Revere | 65% | 58% |
| Christian Yelich | 61% | 61% |
| Howie Kendrick | 60% | 59% |
| Adam Eaton | 60% | 31% |
| Jean Segura | 59% | 63% |
| Elvis Andrus | 59% | 48% |
| DJ LeMahieu | 56% | 58% |
| Adeiny Hechavarria | 54% | 53% |
| Gerardo Parra | 54% | 49% |
| Robinson Cano | 53% | 47% |
A lot of groundballs in there. A lot of groundballs, and Adam Eaton. If you take Eaton out of it, the average of the 2014 column is 58%, and the average of the 2015 column is 55%. Just what you’d expect. Eaton, though, has turned himself upside-down. In a way that doesn’t seem explicable by randomness, Adam Eaton is hitting baseballs in the air. He’s never done this before to this extent. I haven’t come across a good explanation, but that doesn’t mean there isn’t one. Eaton might just be maturing, and realizing he has more strength than he’s been given credit for.
Which can come into play when you start getting better about reading opponents and preparing for how they’re going to attack you. Eaton doesn’t have the kind of power that’ll let him hit a home run by accident, but he might opportunistically be able to deploy a stronger swing. There has been pop in there the whole time. According to the ESPN Home Run Tracker, Eaton hit his one home run last year 111 miles per hour. That’s a real one, not a cheapie, and if a guy’s capable of that sort of homer, it suggests he could be a double-digit dinger sort.
If you examine the numbers, you see that Eaton has mostly started putting more balls in the air against right-handed pitchers. Same-handed pitchers are still keeping him on the ground. And, additionally, Eaton has done a lot of his damage against hard pitches; he’s touched them for 71% of his extra-base hits, as opposed to 56% coming into this year. What that suggests is that Eaton might be hunting for hard pitches, looking to drive them instead of slap them. He could be anticipating fastballs, and driving them better than ever before. It would be one definition of selective power.
Or Eaton could instead just be swinging harder all the time. He might have mostly abandoned the swing that would slap grounders toward third base. It’s a swing that gets programmed into every little guy with speed and bat control, but some guys like it and some guys don’t, and perhaps Eaton prefers himself as a line-drive hitter. I don’t know what might’ve prompted the change, but I don’t think Eaton’s going to complain about how things have gone.
The explanation isn’t entirely clear. The reality of what’s happening is a lot more evident. Adam Eaton, who wasn’t going to add any pop, has suddenly started driving baseballs and putting them in the air. He still can’t be described as a power hitter, but he’s a hitter with power, where he used to be a hitter with speed. The old version of Adam Eaton felt very easily predictable. We had a sense of his ability and his ceiling. Or, did we? You always have to question how much you know. It tends to be less than you think. If we misunderstood Adam Eaton’s power ceiling, almost anyone could throw us for a loop.
Jeff made Lookout Landing a thing, but he does not still write there about the Mariners. He does write here, sometimes about the Mariners, but usually not.

Fascinating piece; thank you for “interrupting” my day at the office. Ha. Also interesting is Elvis’ rate dropping by 11%; that’s not to the level of Eaton, but it seems worth keeping an eye on.
He’s also striking out more: 22.9% in the 2nd half of 2015, 15.4% for all of 2014.
Seems like it would lend credence to the swinging harder thing; trading power for Ks.
I watch both Chicago teams frequently and it blows my mind that Dexter Fowler grades better in center than Eaton
I have seen Eaton taking BP. He has real power. Usually hits balls out, some even dead CF
This is probably true of most any ball player, but dude has some guns http://www.gettyimages.com/detail/news-photo/gordon-beckham-of-the-chicago-white-sox-and-adam-eaton-news-photo/480090844
Let’s look at some of Eaton’s minor league track record:
In 2010 Eaton’s isolated slugging in rookieball was .190.
In high-A just one year later his ISO was .160.
In AAA just one more year later his ISO was .158.
So Eaton started his pro career hitting for very good power, then, despite advancing multiple levels each year over the next two years, continued to hit for above average power.
Mystery solved: this is the hitter he was likely going to become all along. And this fact was about as self-evident as could be.
Not sure he was hitting for very good power. Those ISO marks in the minors are barely above average. The point about it being completely out of nowhere holds up though.
He’s never before hit the ball in the air like this. In the minors, he hit grounders too. Which speaks to some sort of change.
He actually did consistently hit more home runs in the minors. Kind of strange since most guys play into their power as they get older in the minors. Very good observation, too bad we don’t have batted ball data on minor leaguers.
Some of Eaton’s minor league power may have been a result of being in the Arizona Diamondbacks system. He spent a good portion of his development out West, including playing AAA ball in the notoriously hitter-friendly P.C.L.
Eaton played most of entire minor league career out West, either in the desert or higher elevations. All but 4 of his 26 career MiLB HR’s were in these locations. Eaton’s power was less prominent at the AA level playing for the Mobile BayBears on the Alabama Gulf coast.
Eaton’s ISO was above league average in each of the three examples cited above.
Collectively in those three seasons, Adam had an ISO that averaged .023 points above his league. He did gain a very modest boost in ISO from his home parks, where his isolated power was on average .010 better than on the road.
So, safe to say his minor league power was, in general, after adjusting for his leagues and parks, slightly better than average.
And now, this year, the MLB isolated slugging is .146, and Eaton’s is .149.
Case. Closed. Maybe it’s a good idea to think twice, or thrice, before correcting people.
No criticism or correction was made in regards to your ISO numbers, only an added thought.
The fact remains, you forwarded those stats for all the levels/leagues out West in which Eaton played but never offered any numbers for his two stints in AA in the Southeast where he produced only 4 HR’s and his lowest SLG% at any minor league level.
What I really want to know is how did you make that awesome 30 day gb% chart on this site?
Interesting article. Adam Eaton flashed some power in the minors. He also stole a lot of bases. Now that Eaton is doing the former in MLB, perhaps he can follow suit with the latter. If not, the White Sox ought to drop Eaton down to the #2 hole in their lineup and consider using Micah Johnson as their future core lead-off hitter next season, provided he can cut it defensively at 2B.
Ironically enough, I stumbled upon this article after coming to Eaton’s profile page to see if his recent power outburst was a result of him hitting less balls on the ground, and it looks like my hunch was correct. It’ll be interesting to see if he can reach some sort of equilibrium between being able to hit for average and get on base with supplying a bit more power. His fantasy prospects would certainly look quite a bit better if he could be a .280/15 guy with some speed instead of a .310/3 guy with some speed. Personally, I think the bigger question related to his future performance is whether or not he will ever be the stolen base threat he was in the minors. If anything, this season’s performance has only made that question more perplexing. Although his overall steal numbers are rather unimpressive, he’s had two stretches this season where he’s stolen bases in bunches, which suggests the speed is still there. Perhaps he simply hasn’t been aggressiveness enough on the base paths to take advantage of said speed or Ventura hasn’t been giving him the green light after often as he could.
However, I do have to disagree with the notion that his power output has come out of nowhere. Undoubtedly it was surprising given the context and the type of hitter he had transformed into last season, but we’ve seen hints of power from him beyond his ISO marks in the minor leagues. Specifically, he posted a 12.5% HR/FB rate in 2012 and a 6.1% HR/FB rate in 2013. Granted, neither rate was based upon largest of sample sizes, in particular his 2012 figure, but his current mark of 9.8% isn’t excessively out of the norm, especially considering that he’s now at his physical peak. This looks to be more a simple case of cause and effect from a change in approach than anything else.