Designated Hitter

Should the DH be universal?

Pro: Three points:

• Reduced pitcher injuries. “...we can cite the career-altering injuries of players such as Jake Peavy, Mark Prior, and Chien-Ming Wang, or even the serious but less severe injuries of the likes of Josh Beckett, Clay Buchholz, A.J. Burnett and Randy Johnson that could have been prevented with the adoption of a DH.” —Jay Jaffe
• Injuries might be reduced for more-rested position players. The DH in 2020 may have reduced position player injuries for the Diamondbacks. This will be looked at in more detail as we explore whether the Diamondbacks benefitted from the DH.
• It gives aging power-hitters a possible path to play more years in the Majors.

Con: Two points:

• Pitcher at-bats are a great part of baseball. The Diamondbacks’ experiences with Zack Greinke and Madison Bumgarner showed great fan excitement was generated by pitchers who rake. And in the wildcard game, Archie Bradley’s triple was “a defining moment for our club” said Torey Lovullo. Even when an average pitcher got a hit or a productive out, it was cause for a small celebration.
• In 2020, the Diamondbacks used 16 players at DH. The main strategy was to give players half-rest days. In 2020, Diamondback overall team performance at DH was .289 wOBA, including 2 homers. This performance added very little excitement compared to the loss of pitcher at-bats.

How well did the Diamondbacks bat at DH?

The Diamondbacks’ negative 0.8 Wins Above Average (WAA) ranked 22^nd in the Majors (data from Baseball Reference). Let’s look at more detail. The following table has hits, homers, and wOBA of the Diamondbacks at DH.

2020 Season. Data from Baseball Savant.

Observations from the table follow:

• Eight batters had 17+ plate appearances. The other batters had 9 or less.
• Christian Walker’s 62 DH plate appearance was the highest of the Diamondbacks.
• Four players had wOBA above league average: Mathisen, Peralta, Walker, and Calhoun. The first three had wOBAs that were better than their regular plate appearances.

What are possible benefits from the DH in 2020?

Give players partial rest days by playing at DH instead of a position in the field.

• “...Hazen envisions the designated hitter spot being rotated among a series of players rather than going to one player full time.” — Zach Buchanan, Jun 24, 2020
• “The “new-school” model is a whirring mass of position players getting rest while still playing.” — Ben Clemens.

Do rest days lower injuries of position players? Although I can’t prove that the DH was responsible, in 2020 the Diamondbacks reduced the value of lost playing days by more than 86%. Injuries by position players fell from $6.49 M in lost playing days (average for 2018 and 2019, excluding Souza’s pre-season injury), to $0.33 M (extrapolated to $0.89 M for a full season). For details see table.

Diamondback position players, 2020 season. Data from Spotrac.

In September 2020, two players lost playing days due to injury:

• Ketel Marte had no PAs as DH prior to his wrist injury (and 5 after recovery). However, he played two complete games at center field on 9/4 and 9/7, which preceded his injury on 9/8. It is unclear whether playing at DH might have helped prevent his injury.
• Josh Rojas, who had 22 PAs as DH. All 22 of Rojas DHs were prior to his back injury, so playing DH did not prevent his injury.

Reduced pitcher injuries while batting and on the bases.

It appears that in 2020 with the DH, no Diamondbacks pitcher was seriously injured either at-bat or on the bases. Was that because of the DH?

Faster pace when pitchers bat.

“The time between pitches was 20.1 seconds [in the 2018 season] when NL pitchers hit but 24.2 seconds when all other NL hitters were at bat.” — Travis Sawchik

Give players recently promoted to bench positions experience batting in the Majors. The added experience will pay off next season.

The Diamondbacks gave 46 PAs (out of 242 PAs) to players who were in their first season in the Majors. They were Andy Young, Pavin Smith, Daulton Varsho, and Wyatt Mathisen.

Get the most value out of the DH by giving the lion share to a single player, such as an aging power-hitter, who would not be playing otherwise.

This did not happen in the NL. “How many NL teams started the same DH in even half the games they played in 2020? Only three. And how many NL teams started the same DH in two-thirds of their games? That would be none.” —Jason Stark