The Yankees might be betting on DJ LeMahieu and the Coors Field hangover

The Yankees signed DJ LeMahieu last week to shore up their infield. That, of course, has caused some consternation. The move was met with, shall we say, a polarizing reaction, with much of the fanbase up in arms about the team’s apparent disinterest in Manny Machado. Others heralded the move as rock-solid, with the Yankees importing a well-rounded player that suits their needs.

Indeed, LeMahieu does bring some welcome defensive aptitude to an infield where good defense is in short supply. Conversely, LeMahieu hasn’t been much of a hitter outside of his star-caliber 2016, though his offensive profile does contain upside, as he makes contact and strikes the ball with authority.

In fact, LeMahieu may have hidden offensive potential beyond his batted ball profile. LeMahieu’s poor triple slash line away from home with the Rockies (.264/.311/.362) has often been cited as proof that he’s doomed to struggle away from the friendly confines of Coors Field. Yet evidence of a “Coors Field hangover” effect provides more reason to be optimistic regarding LeMahieu’s chances of hitting in New York.

The idea behind the Coors Field hangover pertains to Rockies hitters tendency to hit significantly worse on the road than at home, even from a context-neutral perspective. Colorado’s batters obviously will hit much better at home in an absolute sense, with Coors Field’s mile-high altitudes and wide-open outfields leading to a hitter’s haven, but even after adjusting for that context, Rockies hitters have consistently fallen far short on the road during the franchise’s entire existence.

Neil Paine of FiveThirtyEight examined the gap between Rockies hitters on the road and at home back in 2017. He found that between 1995 and 2017, the Rockies posted a 102 OPS+ at home, above average even after accounting for the fact that Coors Field is extremely hitter-friendly, and an 87 OPS+ on the road. That 15-point gap was easily the largest in the majors.

For over two decades, the Rockies as a whole have hit decently at home and horribly on the road. The extent to which they struggle so much worse than the rest of the league suggests that something about hitting at Coors Field makes it more difficult to hit elsewhere.

Theories have abounded regarding the exact reason why hitters struggle so much on the road when they call Coors Field home. The high altitude in Colorado tends to flatten out pitches, so maybe the Rockies struggle to adjust to the movement of normal pitches once they hit the road. Another theory wonders if the Rockies simply engineer their lineup to take advantage of Coors Field with a bunch of line-drive contact hitters, hitters whose tactics fail to produce away from Coors.

Regardless of the precise cause, there appears to be a systematic reason for LeMahieu’s dreadful away splits. Getting away from Coors Field, then, could boost LeMahieu’s batting line. If there is something inherent in hitting in Colorado that hampers batters’ ability to hit anywhere else, that effect very well may be left behind as LeMahieu moves to New York.

Just how much LeMahieu could improve with more stable home/road environments is anyone’s guess, though research last year from the FanGraphs community suggested that the Coors effect could rob Colorado hitters of several points of OPS+ or wRC+, and subsequently a half-WAR worth of value, perhaps even more. If LeMahieu’s splits even out and he ends up basically as an average hitter, that, along with his plus defensive contributions, would make him essentially a first-division starter, something between an average regular and an All-Star.

The fact that the Yankees even pursued LeMahieu suggests that they see him as a quality starter. Ken Rosenthal of The Athletic (subscription required) did report yesterday that the team saw him as the second-best free-agent infielder this winter, and that their internal metrics indicate LeMahieu has been systematically undervalued offensively. The Yankees have been at the forefront of analytical thought for years, and it would not be surprising if they had good reason to believe that LeMahieu could produce better with the bat going forward.

At the end of all this, I want to circle back to the matter of Machado and make one thing clear; LeMahieu still probably isn’t the infielder the Yankees should be looking for. They ducked under the luxury tax last year with the intention of pursuing the generational free agents on the market, and instead have targeted merely pretty good players. There’s nothing wrong exceeding the luxury tax to sign fine players, provided it’s accompanied with an actual splash to sign exceedingly rare young star free agents.

An offseason that saw the Yankees import both Machado and LeMahieu would be excellent. One in which they signed just LeMahieu and took a flyer on Troy Tulowitzki would profile as underwhelming, or even borderline negligent. This isn’t LeMahieu’s fault, and after examining him more closely, he stands to help the Yankees. At a price of two years and $24 million, the team is probably actually underpaying him. LeMahieu’s hidden upside will be little solace if the Yankees scrimp out on the big free agents, but at least there’s reason to hope for more from LeMahieu.