Evaluating The Big League Ascension of Eloy Jimenez

Written by: Zach Hayes (@PineTarKeyboard)

Follow us on Twitter! @Prospects365

It’s a weird time to be thinking and writing about sports.

But even in their absence, they can still do their best to give us some respite from a world that throws a lot of curveballs at us. Like millions of others, I found myself very suddenly out of work earlier this month, and I’ve hardly had time to process the fact that I won’t be watching the White Sox play the Red Sox at Fenway Park on Opening Day. Though it’s been two weeks since a Spring Training game was played, getting lost in baseball has been just one of many ways of taking shelter in this cloud of uncertainty. That’s how this article got written, and I hope it can be a reminder of the awesome things we’re going to see this summer, whenever it comes.

Anyhow. Before it all went pear-shaped, I was surprised there wasn’t a little more buzz around Eloy Jimenez earlier this preseason as Spring Training got underway. It should be hard for a smiling, bouncing, 6-foot-4, 205-pound youngster with a $75 million contract to get lost in the shuffle, but it genuinely seems like that’s what’s happened.

To be fair, he didn’t set the world on fire as a rookie. His less-than-prodigious speed and awkwardness in the outfield kept him to a pedestrian 1.9 fWAR, along with a respectable 116 wRC+ that was somewhat suppressed by his disinclination to walk. Given how raw the majority of his skillset still is, the fact that he posted essentially a league-average season can certainly be taken as a positive, independent of anything else.

Jimenez and fellow top prospect debutant Vladdy Jr. may have been outstripped in 2019 by Yordan Alvarez and Pete Alonso, but despite not emerging as a world-crushing star from Day 1, there’s plenty of evidence that Jimenez could get there sooner rather than later.

His overall production last year was weighted down by a slow start, as one might expect for a 22-year old seeing the majors for the first time. I’m inclined to believe that the Yordans, Judges, and Alonsos of the world shouldn’t be the bar for every top prospect; Jimenez wasn’t a superstar from the jump, but there’s plenty to get excited about. Even at the most basic level, it’s clear that he generally improved over the course of the year. Behold, a tale of two seasons:

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Or rather, three. The tape essentially tells a story in three parts. After spending just 55 games in Triple-A during the 2018 season, the start of Eloy’s big-league career was a little rough, turning in a below average April and abysmal May sandwiched around three weeks missed with a high ankle sprain. After turning the lights on in June, an elbow injury cratered his July. And of course, there’s the reason to be excited for next year: a 189/184 OPS+/wRC+ in any month is worth noting. He was a true tour-de-force from the middle of August on.

So, how did this happen, and does it mean that the Eloy Jimenez of the season’s last couple months is what we can expect heading into the future? Let’s open the hood and see what we can tell about his habits over the course of his rookie year. Here’s the story of his 2019 as told by plate discipline splits:

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These numbers, while imperfect for measuring whether a hitter’s plate discipline is actually “good” or “bad,” do tell us something about Eloy’s approach. For rookies who are seeing major league pitching for the first extended stretch of their careers, this can give us a window into their ability to make adjustments on the fly and figure out what works and what doesn’t work for them in the batter’s box. Baseball is a game of adjustments; it’s rare for even the most elite to go year to year without tweaks to their mechanics or approach. It’s an under-appreciated skill that’s absolutely necessary to survive at the big league level.

Anyway, that’s a lot of percentages and abbreviations, so here are the main takeaways. We see where the lack of walks comes from; Eloy is a little more swing-happy than the average hitter, and when he swings, he makes a little less contact than the average hitter. For him, this isn’t much a problem, as we’ll see in a moment. The column that raises an eyebrow is his out-of-zone swing percentage.

This is the part where I acknowledge that I am a White Sox fan who probably has some psychological investment in Jimenez playing well. There may be reasons for concern that are equally valid as my optimistic take here. Regardless, it’s also to my analytical advantage that I watched a lot of his at bats in 2019. The gradual high-low-high arch of his O-Swing% catches my eye because it partially affirms my anecdotal observations. Early in the season, pitchers attacked Jimenez by busting him inside with fastballs and baiting him with breaking balls off the outer corner. It seemed to me that after a few weeks and a little time back after injury, his production took off when he stopped biting at sliders in the lefty batter’s box.

Let’s see if there’s any evidence to back this up. Here’s a pitch type breakdown along with heat maps of fastballs (left) and breaking balls (right) thrown to Jimenez through the first two months of 2019 (All Heatmaps courtesy of Baseball Savant):

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Use of the inside fastball in tandem with the low and away breaking ball tracks here. For the most part, Jimenez took the bait, and struggled accordingly. See how far off the corner that big dark blob of breaking balls goes? Hitting the right spot out there was almost a guaranteed whiff for the first part of the season. While Jimenez actually swung at those low and away pitches at a slightly below league average rate (29% vs. 35%), he totally missed a frightening 82% of the time he did give it a shot, well above the 62% league average. Combined with his overall aggressive approach, the result was a lot of swings at a lot of bad pitches. Not ideal, and a perfect recipe for an offensive line about 30% below league average.

We saw above that for the first two months of the year, pitchers primarily went at Jimenez with hard stuff in and spinning stuff away. June’s offensive explosion tells us that whatever pitchers were doing before then, it stopped working in a big way.

Why might that be? Check out the 5% drop in out-of-zone swing rate from April to June. It’s still just a hair above league average and may not seem super meaningful, but finding out where specifically those improvements happened can tell us a lot about what changed for Eloy at the game level.

Remember that Jimenez swung at those pitches out of the zone low and away (Zone 14 on the Gameday chart) about 29% of the time. In June, that number dropped to 19%. Similarly, while he swung at inside fastballs on the hands up and down (Gameday zones 11 & 13) at a 51% clip through the end of the May, he did so just 41% of the time in June. He didn’t just start swinging at pitches out of the zone less—he started swinging a lot less at the pitches he wasn’t doing any damage on. Whether consciously or not, it appears that he picked up on the opposing game plan, improved his pitch recognition, or some combination of the two.

In theory, it’s pretty linear logic. If a hitter suddenly stops swinging at balls with little chance of impact contact, the pitcher is faced with a dilemma: start working closer to the zone and risk getting pieced up, or keep throwing those balls and risk allowing more walks. It’s easy to see if this is what actually played out. To see how pitchers adjusted to Eloy’s adjustments, lets bring back those fastball (left) and breaking ball (right) heatmaps, but for June and July:

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Bingo! Those dark red patches are in much more hittable locations than they were in April and May. Perhaps Jimenez understood that he was essentially getting himself out by swinging at bad pitches. Regardless, when he stopped swinging at them and made the pitcher come to him, he reaped the rewards of his elite power. Jimenez’s in and out of zone contact quality along with his walk rate shows a hitter who over the course of a half-season or so simply started putting a better swing on pretty much everything:

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All of this lines up wonderfully for the first half. Pitchers took advantage of a rookie slugger’s inexperience by hammering him with pitches in spots he didn’t yet have the experience to simply lay off. After a while, he figured out how to recognize and take those pitches, and he started mashing. Problem solved, right?

Ha, no. If you’ve been paying attention, you’ll notice that in pretty much every one of these charts, this whole hypothesis goes straight out the window for the last couple months of the season. Eloy had a tremendous June, dealt with a minor slump and injuries and July, and when he came back, all that newfound plate discipline was gone, with his swing rates reaching season highs across the board in September. Which was also far and away his most productive month. So what are we missing here?

Truth be told, not a whole lot, as far as I can tell. After his return from injury in late July, he resumed his free-swinging ways, only this time, it didn’t matter where the pitcher put it: he absolutely raked.

If I were of the mindset that Eloy is not all that and is more likely to settle into something resembling prime Pedro Alvarez than anything akin JD Martinez or Giancarlo Stanton, I would point out that in September, he actually swung at those low-and-away breaking balls at an above average rate while whiffing on almost 9 out of 10 of them. And I would be right. But it didn’t matter that he went back to swinging on a ton of balls out of the zone, because he hit the hell out of anything he made contact with. That month, his average exit velo of 95.1 MPH tied for the third-highest in baseball, all without any significant deviation from his season-long whiff and strikeout rates. Whatever he was doing well in June, he was doing a different thing even better by the end of the season.

Ultimately, the point of all this analysis isn’t to say that Eloy Jimenez’s success is predicated now, forever and always on being able to resist swinging at junk low and away. Beyond the box score, though, we now know something about Jimenez’s makeup, an as-yet unquantifiable trait that can play as much of a part in success or failure as any physical attribute. It’s good to know something about it if you’re making an assessment of a player’s future.

So think of it like this.

Here we have a 22-year old who stepped into a major league batter’s box for the first time having utterly crushed every level of professional pitching he’s ever faced. He’s dealing with the pressure of a bad ballclub, top prospect status, and signing far and away the biggest contract ever commensurate to his experience.

The majors ain’t the minors: the fastballs are harder, the breaking balls sharper, the command better. Advance scouting is more sophisticated. Pitchers have a plan of attack, and they’re executing to perfection. For quite possibly the first time in his life, Eloy Jimenez is a below average hitter.

In professional sports, and especially a game with as tiny margins as baseball, the ability to make adjustments shouldn’t be taken for granted. I thought Gordon Beckham was the second coming of Ian Kinsler after his rookie year. Pitchers figured out you didn’t have to throw strikes to get him out, and for years, frustrated White Sox fans could nearly dictate his ABs in real time. One high fastball and two low sliders later, he’d be walking back to the dugout.

All that being the case, it only took about 6 weeks for Eloy Jimenez to address a weakness that had never stopped him from succeeding before. That’s a lot harder than you’re probably giving credit for. Once he showed the ability to resist swinging at noncompetitive pitches, he found better pitches to hit, and he took off. Just like you draw it up!

So how did he maintain and even improve upon that June level of production while his plate discipline slid in the wrong direction? Sometimes, hitting is about feel as much as anything else. How good is the hand/eye coordination, the bat control, the pitch recognition? These are things that can ebb and flow even as physical characteristics remain stable, especially for young players. While I wish there was a more scientific way of saying it, I’m inclined to believe that it was simply a combination of health and increased feel that allowed Jimenez to take flight in September without the plate discipline he needed to get himself going in June.

To top things off, here are two more heatmaps. On the left, we have where Jimenez was swinging over the first two months of the season, and on the right, we have his swing locations in September:

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You know what that is? That’s the difference between a rookie who doesn’t know what he’s getting, and a locked-in hitter who knows not just what he’s looking for but is ready to roll when he gets it. If you return to the plate discipline chart way up at the top, this tells us that big September jump in contact rate on pitches in the zone was a more than reasonable tradeoff with the out-of-zone whiffs that came along with it. When a hitter with Jimenez’s strength is able to hone in on a sweet spot like we see on that chart to the right, the results are going to be through the roof.

We might not have actually learned anything about what specific kind of hitter Eloy Jimenez is going to be in 2020 or beyond. But we do know that he doesn’t let things snowball. When everything is going right for him, like it did in September, he’s going to eat the American League for breakfast, lunch, and dinner. But few hitters are lucky enough to have everything go right for more than a few at-bats or series at a time. Over the course of the 2019 season, Jimenez showed that everything does not necessarily need to go right in order for him to be a highly dangerous hitter, and when more things are going wrong than right, he has the makeup to steady the ship and make the necessary adjustments. If only we were all that good at what we do. I look forward to watching him mash whenever this season should get underway.

Follow P365 staff writer Zach Hayes on Twitter! @PineTarKeyboard

Follow us on Twitter! @Prospects365

Featured image courtesy of photographer Jonathan Daniel and Getty Images

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