Zack Cozart Probably Won’t Keep Scorching the Ball

Last week, August Fagerstrom handed Cincinnati fans an ice-cold Gatorade after we’d spent the better part of three months wandering through the Sahara that is the 2016 Reds baseball season.

After quickly touching on the wide range of sadness, of which there is no shortage—the historically bad bullpen, the woeful luck of one Joseph Votto, and oh, the losses—he rationally pointed to a reason for optimism: “[The Reds’] two most encouraging comeback stories, Zack Cozart and Jay Bruce, just so happen to be their two most sensible trade chips.”

Of Cozart, he wrote:

He leads the Reds in WAR. He enters his final year of arbitration next season. He’s always been a gifted defensive shortstop, something every team loves to have, but this year, he’s hitting at career-best levels…He’s become more aggressive at the plate, he’s hitting way more balls in the air than he did early in his career, and he’s hitting them with authority (emphasis mine).

This last piece is what’s so interesting. Watch any Reds game this year—or just stay through the leadoff hitter! I swear, that’s all I’m asking!—and you’ll hear announcers remark that Cozart is just hitting the ball differently this year.

As shocking as it may seem given recent broadcaster rankings, they’re right.

Cozart’s 2016 hard-hit rate of 33% is very good, if not earth-shattering. It ranks seventh amongst shortstops, and league-wide places him in the company of (slightly) more celebrated offensive names like Bogaerts, Kinsler, and Beltre.

But there’s a caveat to Cozart’s great contact. The number isn’t just a career high; it’s a massive outlier, sitting 8.5% above his career average. How many other hitters this year are enjoying similar spikes? I pulled all “jumps” above six points for 2016 qualified hitters, with a minimum of four seasons to ensure a stable career average:

Name	Team	Age	2016 Hard Hit %	Career Hard Hit %	“Jump”
Jose Altuve	Astros	26	34.2%	24.5%	9.7%
Daniel Murphy	Nationals	31	38.2%	28.7%	9.5%
Victor Martinez	Tigers	37	41.5%	32.3%	9.2%
Matt Carpenter	Cardinals	30	43.6%	34.7%	8.9%
Zack Cozart	Reds	30	33.0%	24.5%	8.5%
Buster Posey	Giants	29	40.8%	33.1%	7.7%
Joey Votto	Reds	32	44.4%	37.0%	7.4%
Curtis Granderson	Mets	35	40.2%	33.1%	7.1%
Salvador Perez	Royals	26	35.6%	28.5%	7.1%
Chase Utley	Dodgers	37	41.9%	35.3%	6.6%
Ben Zobrist	Cubs	35	36.0%	29.4%	6.6%
David Ortiz	Red Sox	40	46.9%	40.3%	6.6%
Josh Donaldson	Blue Jays	30	40.5%	34.0%	6.5%
Yoenis Cespedes	Mets	30	39.5%	33.2%	6.3%
Evan Longoria	Rays	30	40.7%	34.6%	6.1%

This list shouldn’t be too surprising. While not a perfect indicator, we know that hitting balls hard is generally better than the alternative—and these guys, with one giant, Vottoian exception, are all in the midst of stellar years by more traditional metrics. Altuve owns baseball’s third-best WAR; Murphy remains one of baseball’s best bargains; Martinez and Ortiz continue to defy Father Time to the tunes of wRC+ of 142 and 194(!), respectively. Even Votto, recovering from a BABIP 60 points below his career average, is rapidly coming around.

The group presents club evaluators, though, with a very tough question: How “real” are these spikes in hard-hit rate, and by extension the jumps in offensive performance? For Cozart, the question for the Reds front office basically translates to: How likely is he to keep the hard contact up, and how quickly should we trade him?

Let’s start with what we know about hard-hit rate. It’s generally a repeatable skill, as a FanGraphs study from last year puts hitters’ YoY correlation at 0.69. We can also say that there’s no real drop in age to adjust for; I found the r-squared correlation between age and hard-hit rate to be 0.02.

It’s not crazy, then, to think that a career-high spike in hard-hit rate could be the start of long-lasting improvement. And if it is, we should see it in the years around the spike: an increase the year before that hinted at a breakout, or retaining/coming close to the same rate in the next few seasons.

But is that the case?

I pulled all hitters with a hard-hit-rate YoY “jump” above 9% since we began tracking the stat in 2002 to see how they fared in the years immediately before and after. In this chart, “Year Before” is the hard-hit rate versus career average for the season prior to the jump, with Y+1/Y+2 representing the two years following it:

Year	Name	Team	Age	Year Before	“Jump” Year	Y+1	Y+2
2007	Edgar Renteria	ATL	30	2.2%	12.8%	-3.7%	-2.4%
2007	Derek Jeter	NYY	33	5.1%	12.5%	0.7%	-0.6%
2007	Ryan Howard	PHI	27	2.0%	12.4%	3.5%	2.8%
2007	Jimmy Rollins	PHI	28	3.5%	11.5%	3.7%	-1.1%
2007	Carl Crawford	TB	25	-1.8%	11.4%	-3.6%	3.0%
2007	Coco Crisp	BOS	27	2.5%	11.4%	-0.4%	-1.5%
2013	Marlon Byrd	NYM/PIT	35	3.6%	11.1%	6.9%	1.3%
2007	Chone Figgins	LAA	29	2.1%	10.9%	-1.9%	-0.5%
2007	Mark Teixiera	TEX/ATL	27	-1.8%	10.7%	3.5%	1.0%
2009	Carlos Pena	TB	31	-0.3%	10.3%	1.6%	6.4%
2007	Aaron Rowand	PHI	29	-2.0%	9.7%	-0.7%	-2.5%
2010	Nick Swisher	NYY	29	-0.8%	9.6%	-3.4%	1.4%
2007	Michael Young	TEX	30	0.4%	9.5%	0.2%	4.0%
2009	Raul Ibanez	PHI	37	2.1%	9.5%	4.4%	-4.0%
2007	Grady Sizemore	CLE	24	0.5%	9.3%	1.4%	-1.5%
2007	Ichiro Suzuki	SEA	33	2.4%	9.2%	0.5%	-1.4%

If you’re looking for a pattern, don’t bother: none really exist, aside from the observation that 2007 was, apparently, The Year of Hitting Baseballs Hard (a poorly anticipated sequel to The Year of Living Dangerously).

The “Jump” years make up a few of the better hitting seasons in modern history: Jimmy Rollins’ MVP campaign of 2007, Teixiera’s famous Rangers/Braves split season in which he posted a wRC+ of 146, even a Raul Ibanez “I’m Not Dead Yet” season with Philadelphia at age 37.

More importantly, though, surrounding these seasons on either side is case after case of regression—and not even particularly close regression at that. There doesn’t seem to be any ability to carry over a hard-hit-rate jump into the next year or beyond.

These seasons aren’t necessarily the same as those supported by BABIP-fueled mirages…but they are propped up by a contact rate that just doesn’t seem to hold up in any type of long run. It’s something that makes sense on an intuitive level: no one, even someone as skilled as a big-league hitter, wakes up and says, “Oh, yeah—that’s how I can hit the ball hard from now on,” then keeps it up for the rest of their career.

A 162-game baseball season may seem long, but it’s subject to many forms of chance, including the odds that some years you’ll strike the ball harder than others. For the purposes of evaluating our 2016 list, it’s info that is more “useful” than immediately actionable: every player on the list except Cozart is signed through at least 2018, while Ortiz, in a Breaking Bad-level identity switch, will hang up his spikes to try his skills as a masseur in Minneapolis.

But it’s a worthy piece of evidence that our protagonist will spend next year likely reverting to average or even worse at the plate—and that the Reds, by extension, should pursue every possible trading avenue for Cozart this summer while the hitting is hard.