clock menu more-arrow no yes mobile

Filed under:

Curious About Zack Davies

Did he return from the IL as a different and improved pitcher?

Zach Davies
Zach Davies
Photo by Christian Petersen/Getty Images


The Orioles drafted Christian Walker and Zach Davies. The Diamondbacks are their fourth and fifth teams in the Majors per Baseball Reference.

Last season, Zach Davies’ strengths were his 34.5% hard hit percentage and his 87.4 MPH average exit velocity. They were the best of the Diamondback’s starters (minimum 2 starts, data from Baseball Savant). Also, his .315 On-Base-Percent (OBP) ranked as the fourth best starter. In general, his strengths were weak contact and keeping batters off the bases.

Perhaps to avoid rookie pitchers needing to pitch too many games, the Diamondbacks re-signed him. From that point of view, it was a good move because so far he started 15 games. If he had avoided injury it would have been a great move.

“He throws strikes. He takes the ball. He has an idea how to work around situations. He’s a smart pitcher....Adding Zach was obviously a quality starting pitcher for us.” — Mike Hazen, January, 2023

This season, Zach Davies received a lot more run support. FanGraphs’ measure of run support, RS/9, increased from last season’s 3.08 to this season’s 5.93 (15 games).

Zach Davies increased his frequency of his four-seam fastballs from 4.7% last season to 21.0% this season while reducing his sinkers from 49.6% to 33.6%. That change in pitch distribution was one reason behind his continued success.

How was Zach Davies different after being on the IL?

On 20 July, Zach Davies was put on the IL because lower back inflation. During his rehab in AAA, Zach Davies made changes suggested by Brent Strom.

“I hope he pitches like he did his last outing [in AAA rehab]. He pitched very well. He did some of the things I asked. He didn’t do the things I asked in the first [AAA rehab] outing. I wanted him to elevate more, throw cutters in to lefties, not just go fastball away, changeup away, which is his M.O. The last game he pitched six innings, three runs, which I defy anybody in the MLB to go six innings three runs in Reno. It’s hell to pitch there sometimes. He did a nice job and I expect him to be good, I really do.” — Brent Strom, August 2023

I was curious about whether he returned as a different and improved pitcher. Clues follow.

He returned on 26 August. His first two starts were awesome for two reasons:

  • He allowed 2 earned runs in 11 innings pitched.
  • In his two starts, reaching 11 strikeouts were noteworthy. He improved his strikeouts per batter faced from 17.8% (this season prior to his return) to 25% after his return. That was a significant increase. For reference, all Diamondback starters (this season through 7 September) averaged 21.0% strikeouts per batter faced.

For two games, Zac Davies looked like a strikeout outperformer instead of his previously known strengths of weak contact and keeping batters off the bases.

From 1 August to 7 September (three starts for Zac Davies) he continued to demonstrate his strength of weak contact. His .016 homers-per-PA was the best of the Diamondback’s starters. His .079 solid-hits/barrels per PA was the second best of the Diamondbacks starters behind Merrill Kelly.

On 6 September the first two Rockies walked.

Zach Davies spent 15 pitches (an innings worth of pitches) on the first two batters. He walked them both. Predictably, the power part of the lineup (third and fourth batters in the lineup) drove in those runners.

Looking at gameday pitch locations, the first two batters swung at 3 of 6 pitches in the strike zone (plus one pitch outside the strike zone). Perhaps those two batters got on base by swinging at very few pitches.

Without the success of those two batters, instead of 5 earned runs in 3 innings, my view is that Zach Davies would have allowed only 3 earned runs and completed 4 innings (a marginally acceptable start). In other words, it was reasonable to expect that next game he could have a better result.

I am encouraged by the extra strikeouts from the new and improved Zach Davies. I suspect this bump in the road can be fixed while retaining his improved strikeout rate.

What happened when Zach Davies started on 11 September?

First three innings. In the first inning three Mets’ batters did nor swing until the fifth pitch, and one batter did not swing until the fourth pitch. Seeing that strategy did not work, the next two innings most Mets’ batters had swung at the first or second pitch. Through 3 innings Zach Davies had allowed zero runs with 2 hits, 3 strikeouts, and zero walks. I was very encouraged that perhaps Zach Davies made a needed adjustment and retained his improved strikeout rate.

Fourth Inning. The first batter did not swing until the sixth pitch and struck out. Jeff Mc Neil, the second batter, swung at the first pitch for a homer. As homers go, it was marginal with 103.2 MPH exit velocity and only 370 feet distance. Nevertheless, based on how he pitched after the homer, Zach Davies did not quickly recover his winning mindset.

Zach Davies walked the next batter on six pitches, including four pitches far from the strike zone. He walked the next batter on 5 pitches, although they were closer to the strike zone. Those walked runners scored on a hard hit double (107.8 MPH). He walked one more batter before getting two outs to end the inning.

By the eighth inning the Diamondbacks tied the game. Knowing the Diamopndbacks will answer back will hopefully allow Zach Davies to focus on keeping his winning mindset even after allowing a marginal home run. Meaningful September games are emotional and intense - and that’s how Zach Davies wants it!

“It’s fun baseball. I’ve been on teams that were losing down the stretch and I’ve been on teams that are winning down the stretch. So, when you’re playing meaningful September baseball, it’s always fun. Each game is more emotional and a little bit more intense, and that’s how you want it.” — Zach Davies


Although Zach Davies is a number 4/5 starter, his strength of allowing weak contact has often given the Diamondbacks’ offense chances to win games. Upon his return from the IL, he was an improved pitchers with an increased percentage of strikeouts per batter faced. Then he had a setback against the Rockies.

Against the Mets, an adjustment was made and he pitched very well for 3 innings with 3 strikeouts. However, the second batter of the fourth inning hit a home run and Zach Davies did not quickly recover his winning mindset.