Universal DH and The Defensive Spectrum

Among the rule changes implemented for the abbreviated 2020 MLB season, the introduction of a universal DH is a particularly polarizing one. For now, the universal DH will take effect for 2020 alone, but that temporary status hasn’t done much to quell speculation that it is in fact here for the foreseeable future. For some purists, spurning the DH in the NL is about maintaining a key strategic element to baseball. For some of those in the Pro-Universal DH Camp, it’s simply a matter of taking the bat out of the hands of players who collectively hit .131 last year.

This piece doesn’t wade into that debate. Instead, the aim here will be to consider one particular downstream effect of a universal DH: creating opportunities for players who otherwise might have been passed over. While it is exciting to consider the addition of Yoenis Céspedes, Kyle Schwarber, or Wil Myers to lineups that might otherwise have gone without their established bats in some games, this rule also benefits players who are not yet household names, and might not have had so clear a chance to become so otherwise.

It is tough to discuss the impact of the universal DH without first considering players through the lens of the position(s) they play. To be a designated hitter is to be, by definition, position-less; a presence in the lineup and an absence in the field. Given this, DHs have come to fit a particular mold. They are less effective in the field, on average, than other position players. They are older on average too. In short, they have either started at the bottom of, or otherwise slid down, the defensive spectrum.

Simply put, the defensive spectrum is the concept that defensive positions are valued and ranked in an ordinal manner, given how difficult they are to play relative to one another. Playing shortstop requires a more diverse skillset than playing first base, for instance. As such, finding a viable shortstop is a tougher ask than finding a viable first basemen. Certain positions, particularly those up the middle of the diamond, require more skills and feature more fielding opportunities in an average game. Those up-the-middle positions occupy the top echelons of the defensive spectrum, while the designated hitter “position” occupies the bottom-most tier, should it even be considered.

Each position on the defensive spectrum may be weighted, in terms of runs/WAR, based on the relative value of that position. In their book “Future Value”, Eric Longenhagen and Kiley McDaniel provide an informative summary of the defensive spectrum and how it is shifting. Below is a brief excerpt from their book (italics added here):

As compensation for defensive limitations, players lower on the defensive spectrum must play outsized roles offensively to earn their opportunities. That is changing some, in the present era of offensive-minded middle infielders among other factors (shifts, for one), but players at the corners nonetheless generally hit slightly above league average.

As part of these phenomena, the bottom of the defensive spectrum becomes crowded, first with bat-first young players like Vladimir Guerrero Jr. or Franmil Reyes. Perhaps more importantly though, lower defensive spectrum traffic is compounded by defensively limited veteran players like the aforementioned Cespedes or Myers. Longenhagen and McDaniel outline what this means for some players quite succinctly, stating that, “This is how 4A hitters get squeezed out of big league jobs: downward pressure on their profile from big league mashers tumbling down the spectrum and into their positional bucket.”

This is a key repercussion of the universal DH; In 2020, those 4A players are getting opportunities that hitherto have never existed in the National League.Even just a few games into 2020, it is increasingly clear that opportunities are arising for the NLs designated hitters that might not have been available otherwise.

Filtering for NL DHs on FanGraphs presents an interesting array of players. Jesús Aguilar, a waiver pickup by the Marlins, has the most DH plate appearances in the NL at the time of this writing. 4A players like Kevin Cron, Josh Naylor, Matt Davidson, Ty France and more are likely to get a healthier share of PAs given the extra rung on the defensive spectrum ladder. The extra rung also means DH homes for NL players like Jay Bruce, Marcell Ozuna and Howie Kendrick, leaving space for younger player on the bubble.

There is no counterfactual for 2020; no one can say whether those players mentioned above would have been carried on a 26 man roster in a regular 162 game season. It’s also tough to quantify at-bats young hitters might in turn lose out on as pinch-hitter roles dry up with the absence of pitchers in the lineup. Still, the point remains that this rule change means more plate appearances for position players by way of the DH. While that positive impact for 4A players will inevitably be diluted by veterans and the defensive spectrum crunch, it provides unprecedented opportunities nonetheless.