According to a report from the New York Post’s Jon Heyman, the Diamondbacks are bringing back right-handed pitcher Zach Davies on a one year, $5 million deal with $3 million in incentives. Some outlets have also reported a $5.5 million mutual option for 2024.

Given that Davies just had a 4.09 ERA and 98 ERA+ in his age-29 season, the contract looks like a steal for the D-backs. Heck, Corey Kluber is seven years older and had a 4.34 ERA last year, but reportedly got $10 million guaranteed from the Boston Red Sox with an $11 million club option for 2024. (Granted, Kluber has a pair of Cy Young awards in his past, and his peripherals in recent years are a step above Davies’.)

In a sense, Davies is a well-known commodity. He throws an unassuming high-80s sinker, one of the best changeups in baseball — more on that later — and an occasional curveball or cutter that help keep hitters off balance. Despite the fact that Davies’ pitch arsenal has essentially remained unchanged for a number of years, his results have oscillated dramatically.

In 2021, the right-hander had the worst season of his career, tallying a 5.78 ERA, 1.60 WHIP and a league-leading 75 walks. In 2022, he rebounded with the aforementioned 4.09 ERA and a respectable 1.30 WHIP. Given that his pitch usage rates were almost identical from 2021 to 2022, the reason for that difference is not immediately apparent. Did the mere presence of Diamondbacks pitching coach Brent Strom supernaturally swing batted ball outcomes in Davies’ favor?

A fun and simple way to compare Davies’ 2021 and 2022 seasons is to compare his percentile rankings on Baseball Savant. To be clear, the number on each scale represents the percentage of other pitchers Davies outperformed in that particular metric. For example, the 16 in the BB% category for 2021 means Davies’ walk rate was better than 16 percent of his peers in 2021 (not that his walk rate was 16 percent).

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A couple of things stand out. First, Davies actually had a couple of bright red categories in 2022, both of which were related to quality of contact. One of them was average exit velocity, which improved dramatically from the lower quartile in 2021 to the upper quartile in 2022. Along those same lines, Davies’ hard-hit rate was better than 76 percent of other pitchers in 2022, compared to just 16 percent in 2021.

The other takeaway is that most categories saw only modest improvement from 2021 — probably less than you’d expect for a pitcher whose ERA plummeted from 5.78 to 4.09. Davies’ strikeout and walk rates, in particular, did not change much. His 17.9 percent strikeout rate in 2022 was still well below-average. His 9.1 percent walk rate in 2022 was both higher than the league average and higher than his career mark of 7.9 percent. Frankly, Davies’ 98 ERA+ appears to have been propped up by good batted ball luck, as indicated by an unsustainable .257 BABIP (batting average on balls in play).

That is not to say that Davies’ improvement in 2022 was just an illusion. Exit velocities against all four of Davies’ pitches dropped noticeably from the year prior. In particular, Davies’ changeup returned to its elite level from past years. It was the best changeup on the Diamondbacks, and arguably one of the best in baseball.

Zach Davies, Nasty 79mph Changeup. 👌 pic.twitter.com/vpUCkuEuSN

— Rob Friedman (@PitchingNinja) April 21, 2022

Davies generated whiffs on 32.2 percent of swings against his changeup in 2022. That was actually a slight drop from 2021, when he got whiffs on 36.5 percent of swings. What really changed about Davies’ changeup in 2022 was what happened when it was put in play. Opposing hitters batted just .187 against it with a .325 slugging percentage. Those numbers are backed up by an impressive average exit velocity of just 84.3 MPH.

On the season, Davies’ changeup had a run value of minus-14 runs (lower is better), which was tied for second among all changeups in baseball. The only pitcher in baseball whose changeup graded out better in 2022 was unanimous NL Cy Young Award winner Sandy Alcantara. Davies having an elite changeup is not a new development. He had similarly elite run values on the pitch in 2019 and 2020.

Unfortunately for Davies, his sinker grades out well below-average, essentially cancelling out the positive impact of the change. In 2022, opposing hitters hit .268 with a .485 slugging percentage when they put the sinker in play, and the expected batting average and slugging percentage against the pitch came in even higher at .279 and .515, respectively. As long as Davies is throwing a pitch of that caliber more than 50 percent of the time, his ceiling as a pitcher is severely capped. For what it’s worth, Davies’ sinker did grade out better in 2022 than it did the year prior, though not by much.

It’s also worth noting that Davies’ cutter saw improved in 2022. The hard-hit rate on the pitch decreased from 32.4 percent in 2021 to 16.7 percent in 2022. Granted, the sample there is quite small, as Davies only used the pitch 5.8 percent of the time in 2022. Nonetheless, it was effective for what it was. Davies used it almost exclusively to lefties, often trying to jam hitters high and inside. His average vertical location on the cutter was about six inches higher in 2022 than it has ever been.

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Throwing the cutter higher in the zone was probably not an accident. Davies’ cutter is a bit of an anomaly, with good vertical ride but very little horizontal movement. He has used the pitch more frequently in the past, topping out at a 14 percent usage rate in his very successful 2020 campaign with the San Diego Padres. Davies has since cut back his usage against lefties and has gone from little to no use of the pitch against righties.

Davies probably won’t ever be a big velocity guy, but it’s worth mentioning that his velocity was up a tick across the board in 2022. His sinker saw the biggest gain, going from 88 MPH in 2021 to 89.6 MPH. It was his highest average velocity on the sinker since 2018. Granted, it’s hard to to say how much of a difference that uptick made.

Ultimately, Davies is a 29-year-old starter who relies heavily on two pitches, in which the negative impact of one essentially cancels out the positive impact of the other. He was better in 2022 than the season prior, but he probably wasn’t as good as his 4.09 ERA indicated. Moving forward, Davies’ 4.83 FIP and 4.57 xFIP are probably more accurate predictors of his ERA.

Nonetheless, given the state of the free-agent pitching market and the lack of stable options in the Diamondbacks’ starting rotation, re-signing Davies for $5 million makes a lot of sense. As long as his changeup stays elite, the righty has a good chance to be a steady presence in the rotation for a second straight year.

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Top photo: D. Ross Cameron/USA TODAY Sports