How Good Is Zack Cozart?

As usual, Mike Trout is at the top of our WAR leaderboard. That will only be true for a little while longer, however, as Trout’s lead is down to just one tenth of one win, and he’s unfortunately on the shelf for the next couple of months. Based on the current trajectory, at some point in the next week or so, Zack Cozart will usurp Trout at the top of that list. For all the great performances we’ve seen in the first half of 2017, it’s the Reds 31 year old shortstop who is currently stealing the show.

While the Reds are currently fringe Wild Card contenders, sitting at 28-30, the reality remains that they are very likely to be sellers instead of buyers over the next two months. The team is clearly prioritizing the future over the present, and with a league-worst pitching staff, it is unlikely that the Reds will manage to stay close enough to the win-now teams in the NL to incentivize the front office to dramatically shift course in an effort to take advantage of a stronger-than-expected first half. And as a team looking towards the future, the most obvious trade chips are impending free agents, which is a class Cozart also falls into. When you’re a rebuilding team with a player headed towards free agency who is nearly leading everyone in WAR, a trade seems inevitable.

So as the Reds and the rest of baseball head towards the July 31st trade deadline, perhaps no question will loom larger than this one: how good is Zack Cozart now?

Pretty clearly, we can say with some confidence that he’s not actually the best player in baseball. While Cozart has had 225 fantastic plate appearances this season, he’s ran 2,500 far more mediocre plate appearances before this year, and the weight of his career should not be outweighed by two strong months. The fact that Cozart is already about a win ahead of his next best full-season total tells you something about how out of line this performance is from his own track record.

But we also seem to be living in an age where track records may not be as predictive of future performance as they once were. Players are making dramatic and sudden changes to their core skillsets, and it seems like every day we’re publishing a story about Ryan Zimmerman, Yonder Alonso, Aaron Hicks, or Justin Smoak, dramatically altering what we’ve known about them as hitters for a good while. So while Cozart’s track record remains an important part of projecting his future, we also have to acknowledge that guys like Daniel Murphy have shown that players can and do make dramatic changes in their career trajectories, and those changes don’t happen solely to young “breakout” players.

Sometimes, guys we think we have figured out just change overnight. Sometimes, guys we think have dramatically overhauled their core skills go right back to being what they were previously. Projecting the future of guys who have massive outlier performances like this is not easy, nor has anyone really figured out how to tell the truly changed from the just-on-a-good-run types. But we can still take our best shot at it, and try to discern the legitimacy of the performance as best as we can.

Often, I encourage people to look to the projections as a baseline. In this case, that isn’t particularly helpful, as there isn’t much agreement among the forecasts about what Cozart’s season means.

Heading into the season, ZIPS and Steamer basically had Cozart pegged for the same batting line, with nearly identical forecasts in each of the major categories that drive offensive performance. However, the two systems have dramatically diverged on their rest-of-season forecasts, with ZIPS far more aggressively adjusting its forecast to account for the 2017 performance, and concluding that Cozart is now an above-average big league hitter, moving the wRC+ forecast up by 26 points. Steamer is far more reserved in how it is incorporating 2017 data, moving up only 12 points of wRC+.

The difference relies almost entirely on what the systems believe about contact quality. While part of the Cozart’s strong start is a huge spike in his walk rate — with 31 walks, he’s six off his career high, set last year — neither system sees his current walk rates continuing, nor is there any real disagreement over how much his new walk rates should be incorporated into the projection. And since his strikeout rate is in line with career norms, that obviously isn’t moving much either.

But ZIPS looks at his current .272 ISO and .400 BABIP and believes that those are signs that Cozart has corrected the flaws that made him a career low-BABIP/moderate power guy, and is significantly more confident that those improvements signal a change in his overall abilities. Steamer still sees a guy with a career .283 BABIP and expects that he’ll regress back almost entirely to that number, while thinking that his power remains decent but unspectacular.

One of the nice things about 2017 is that, when it comes to contact quality, we now have more tools than we used to, so let’s look under the hood a bit. First, let’s look at what Tony Blengino wrote about Cozart over the winter, when looking at his batted ball quality.

Until 2016, Zack Cozart had never posted anywhere near league-average offensive numbers over a full season. To do so, he had to experience very good fortune on fly balls (75 Unadjusted vs. 48 Adjusted Fly Ball Contact Score). He’s always been a pop-up machine, he hits his grounders very weakly, and his 2016 liner rate was very high compared to past seasons. Lot of warning signs for a fairly significant backslide in the near term. Potential trade partners, be forewarned.

That warning was based on Cozart posting an average exit velocity of 86.6 mph last year, well below the 88.7 mph average for NL shortstops. This year, with his ISO and BABIP sky high, his average exit velocity is… 84.8 mph. Cozart is actually hitting the ball with less authority, on average, than he did a year ago. That’s perplexing.

As we’ve noted, though, average isn’t necessarily the right way to look at Statcast data. Having two balls hit at 75 mph is not the same thing as hitting one ball at 100 mph and one ball at 50 mph. Production is less about the aggregate of all of your batted balls, but more about the distribution of them, and how frequently a player can hit balls in an area where you can expect good results. To help illustrate this, MLB is tracking percentage of balls hit 95 mph or harder, since that is around the point at which batted balls become productive.

This year, 28% of Cozart’s batted balls have been hit 95+ mph. Last year, 27.8% of his batted balls were hit at 95+ mph. There’s just no big change there.

What about focusing just on balls in the air, which is where most of the damage is done? This year, he’s hit 27 balls in the air at 95+ mph, putting him on pace for 72 such batted balls per 600 plate appearances. Last year, he hit 69 balls in the air at 95+ mph in 508 PAs, which translates to 81 batted balls per 600 PAs. His average EV on FB/LDs is 89.7, basically unchanged from the 89.5 mph mark he put up a year ago.

So, Cozart isn’t really hitting the ball any harder this year than he has previously. He hasn’t cut down on his infield fly problem, which is one of the primary reasons he’s run low BABIPs throughout his career. There’s no big change to his pull rates or his launch angles, like Daniel Murphy’s breakout included. But on nearly every batted ball type, Cozart’s results have just been dramatically better this year than in the past.

That’s a career-best wOBA in every batted ball category, with the flyball wOBA being especially notable. As a guy who doesn’t hit his fly balls very hard, and hits a lot of infield flies, Cozart has consistently been among the least productive hitters in baseball when he’s hit a non-line-drive airball, but this year, his flyball wOBA puts him in the same range as guys like Edwin Encarnacion, Nelson Cruz, and Kendrys Morales. It’s hard to describe that as anything besides good luck.

As you might expect, based on this, the gap between Cozart’s actual wOBA and his expected wOBA based on exit velocity and launch angle is the largest in baseball, at 104 points. Because he plays in a park with a short porch in left field, he’s always outperformed his xwOBA by a little bit, running 20 to 30 point differences the last two years, but this is far beyond just a park factor. Cozart has simply had more balls get productive results that we wouldn’t have expected to be hits than most any other hitter in baseball.

Obviously, no one is going to trade for Cozart expecting him to keep this up, and it’s not any kind of great insight to say that a guy with a career 88 wRC+ won’t keep running a 174 mark, better even than Trout’s career average. Everyone would know regression is coming even without any Statcast data. But in looking under the hood, I think I’m probably more inclined to go with Steamer’s less-optimistic forecast for his batted ball results than I am to side with ZIPS, as there just isn’t much here to support the idea that he’s a significantly changed hitter. It just looks like Cozart has, for a couple of months, gotten really good results out of mediocre batted balls.

That doesn’t mean Cozart isn’t a useful player. Even Steamer’s more pessimistic forecast has him putting up +1.6 WAR over the rest of the season, as he’s a quality defensive shortstop who won’t kill you at the plate. And if you go back to the start of the 2015 season, Cozart has now run a 114 wRC+ in nearly 1,000 plate appearances covering his last three years, so it’s pretty clear that he’s not the offensive black hole that he was earlier in his career.

But he’s nearly 32, his power and BABIP spikes don’t look to be based on any substantial change in contact quality, and he still hits way too many infield flies. If you’re a contender looking for an offensive upgrade, you’ll want to align your expectations accordingly. Cozart can absolutely help a contender down the stretch, but the expectation should be closer to an average bat with a solid glove than any kind of impact offensive upgrade.

For the Reds, this hot streak couldn’t be any better timed, but they also should recognize this for what it is, and cash in while the cashing is still good. Zack Cozart is a quality big leaguer, but he’s not a great fit for the Reds in their long-term rebuild, and this doesn’t look like some Murphy-esque transformation that should convince them to keep re-sign him instead of moving him to a win-now team.