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Arizona Diamondbacks 2017-18 off-season issues #5: Starting pitching

Can the huge improvement in 2017 be sustained?

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Divisional Series - Los Angeles Dodgers v Arizona Diamondbacks - Game Three Photo by Christian Petersen/Getty Images

Absolutely no consensus to be found here, with none of the ten answers getting more than 14% of the vote. You would have to add the top four categories together to reach half the choices. I’m very surprised it ended up as high as 5.55, given how well the D-backs ranked in starting pitching this year. Would like to hear in the from those who voted this 8+.

2017 starters

  • Zack Greinke 32
  • Patrick Corbin 32
  • Robbie Ray 28
  • Taijuan Walker 28
  • Zack Godley 25
  • Randall Delgado 5
  • Anthony Banda 4
  • Shelby Miller 4
  • Braden Shipley 3
  • T.J. McFarland 1


  • 13.9 bWAR above average at the position (2nd in MLB)
  • 66-51, 3.61 ERA, 988:327 K:BB

2018 depth chart

  1. Zack Greinke
  2. Robbie Ray
  3. Zack Godley
  4. Taijuan Walker
  5. Patrick Corbin
  6. Anthony Banda
  7. Braden Shipley
  8. Shelby Miller

It was a startling swing for the Arizona Diamondbacks this year in terms of their rotation. The position was 26 teams better than it was in 2016, when their starting pitching was 28th in the league, at 3.9 bWAR below average. This season, the only team above them by that metric was the Washington Nationals, at +14.3. fWAR largely concurs, rating the D-backs 5th, at 23.2 fWAR above replacement, an improvement of 21 spots and 14.3 wins on the previous season. But can the team repeat their strong showing in 2018?

While the team ERA for 2017 was 3.61, fielding independent measures such as FIP and xFIP both come in a little higher, at 3.71 and 3.77. Those have been shown to be more predictive of future performance than “pure” ERA, so Arizona might be due a little bit of regression next year. Those most at risk are Ray, whose FIP was 0.83 runs higher than his actual ERA, and Walker (+0.55). The biggest improvement should come from Banda, whose FIP was actually fractionally below Ray’s. If we use the FIP of #1-5 on the depth chart, and presume equal innings from each, that would give us an expected ERA next year of 3.72, a little above this year.

However, switching out Corbin for Banda drops the collective figure to 3.61, exactly at this level. With Corbin a very expensive #5, projected to earn $8.3 million this year, and Banda at league minimum, it wouldn’t surprise me to see Patrick dealt this winter. The downside would be a significant reduction in depth; it would be extremely unlikely for the team to go through the year using just five starters. Part of the reason for the success this year was rotation stability: we only needed 17 games from outside the five most-used starters in 2017. Those games produced a collective 3-8 record with a 5.67 ERA, so you can see how our stability was a positive.

The X Factor for 2018 is Archie Bradley, who had a brilliant campaign this year, after his move to the bullpen. The question is, should he be moved back to the rotation? 200 innings of peak Archie would clearly be more valuable than 75. However, would he be as good a starter as he was a reliever? He has made no secret of his desire to return to the rotation, though he also understood how important his role was this year. Speaking at the beginning of this month, GM Mike Hazen said, “he hopes to settle on Bradley’s 2018 role sometime in the next two weeks,” in order to plan out the off-season needs. So we may hear the decision very soon.

There was a possible hint that Bradley may be rotation-bound, with a report over the weekend which said, “One pitcher the club seems to be considering as a relief possibility is right-hander Braden Shipley.” makakilo also noted Shipley’s good performances out of the bullpen, albeit in a small sample size, and he would be a candidate to replace Bradley, with the ability to go more than one inning if necessary. Shipley seemed open to it, saying “At the end of the year, I kind of really figured out how the bullpen works. I figured out my routine, and I felt pretty good. Right now, I just feel like whatever I need to do to help the team.”

For now, I’ve left Bradley off the depth chart. He could end up being just about anywhere on it, since there’s no way to know how effective he would be, if he does return to starting. I’ve also put Shelby Miller right at the bottom. While everything I’ve heard suggests that his rehab is going very well, it seems unlikely he’ll be pitching meaningful innings for the D-backs before the All-Star break next year. I’m going to take any production from him as a bonus - and that presumes Arizona opt to tender Miller a contract for 2018.

There are still some question-marks over the other members of the rotation. Greinke will be a 34-year-old, and no less expensive. Ray needs to keep the walks - and his pitch count - down. Godley will have to prove 2017 is the real deal, and he is not the 2015-16 version, which had a 5.34 ERA. But overall, I think all the pieces are in place for another successful season. At least, providing whatever the cause of the huge improvement this year - coaching, catching or whatever - is still present in Arizona for 2018.