2018 D-backs vs. 2019 D-backs: Pitchers we kept

tl;dr to the above question. No. While the D-backs got strong improvements from a number of their position players, most notably Ketel Marte, the same cannot be said for the pitching staff. Perhaps this is why the team chose to part ways with Mike Butcher a couple of weeks ago? Even though Arizona was still slightly above the NL median in terms of pitching age (28.6 years vs. 28.4), you’d like to see players, especially the younger ones, trending in the right direction. But the sole significant sources of overall improvement in production were Yoan Lopez, and that was basically entirely due to him throwing 60.2 innings this season, rather than 9.0, plus Matt Andriese going from suckage to replacement level.

Admittedly, some of that was outside of Butcher’s control. Zack Greinke would almost certainly have followed suit, but spend the second half of the season in Houston, rather than Arizona. The slumps of Yoshihisa Hirano and T.J. McFarland can, perhaps, be partly chalked up to reliever volatility, and the team was apparently able to get Archie Bradley back on track, after his early season struggles. But we also saw Butcher unable to fix Zack Godley, in what seemed perilously close to the same way he was unable to fix Shelby Miller. Though I guess the team couldn’t fix Trevor Cahill in the pre-Butcher era, so it’s clearly not just him.

[Irrelevant aside. When you Google “Mike Butcher pitching coach”, this is what you get. I feel we were missing an untapped opportunity for some truly innovative pitching mechanics on the mound at Chase Field...]

Below is the table, comparing production across the pitchers who were with the D-backs organization in 2018 and for at least part of 2019. They are in descending order of 2018 bWAR, so the most productive there are at the top.

Ouch. That’s almost the reverse of the situation with Arizona’s position players, where there was improvement virtually across the board. While McFarland and Hirano were the year’s biggest losers. Jimmie Sherfy and Matt Koch also failed to reproduce their 2018 form, while injury all but entirely robbed the Diamondbacks of the services of Silvino Bracho and Taijuan Walker. But I was also surprised to see Robbie Ray’s value so low, because pitchers that miss so many bats are typically considerably more valuable. There have been 46 seasons where a qualifying pitcher ha posted s a K-rate of 11 or better. The median for those is 5.9 bWAR; only three came in at lower than 3.3. Ray owns two of them, his 2017 (0.8) and 2019 (1.5) - the other is Chris Archer’s 2017 (1.5).

While clearly a factor, it’s not just about the walks Ray allows. Kerry Wood managed to put up 6.1 bWAR in 2003, despite very similar numbers to Ray this season, in both K% and BB%. Kerry was at 30.0% and 11.3% that year, while Ray was at 31.5% and 11.2%. But Robbie gave up six more home-runs, in 36.2 fewer innings of work, leading to a SLG against which was 97 points more, and had a BABIP that was forty points higher. With free agency looming, will 2020 be the year that Robbie Ray puts it all together, and takes it to the next level? Or is the mirage of ace Ray going to remain in the distance - and likely to be reached for another team, if ever?

As for the rest, the good news is. among those who’ll be back next season (thus excluding Greinke and Godley), there’s almost nothing but upside. Though we don’t know for sure who’ll be in that group, with McFarland’s team option remaining to be exercised or not, and Hirano a free-agent. Most of the rest should be around: can Andriese continue his meteoric rise past replacement level, maybe reaching the stratospheric heights of mediocre? Let’s not get our hopes up yet though, Or perhaps Koch can turn it around, though with his low K-rate, I’m not certain of his value. A truly “fixed” Bradley would help, and of course, a full season of a healthy Taijuan Walker is almost certain to be a major improvement.