The D-backs’ collapse seemed rather sudden in the moment. A team that had been above .500 for three consecutive years and fairly aggressive in free agency (by their standards) somehow found themselves with a 77-145 record from 2020-2021. In hindsight, it seems a bit more predictable. The impoverished farm system that GM Mike Hazen inherited left him with few high-quality young replacements for aging veterans, so with a lack of resources at his disposal, the team extended their core group of position players. If their production could last until the farm system was fully operational again, the team would have bridged the gap smoothly between two windows of competition. But it didn’t. A combination of aging, regression, and bad luck spiraled the organization to the worst record in baseball.

That’s the story in a nutshell on the offensive side of the ball. For the pitching, however, the collapse looks quite different, and it’s also far more important. If we glance back at 2017, the D-backs were led by their starting pitching. The unit was the 3rd best group in MLB by fWAR. In 2018, the group regressed somewhat, but still finished 11th. Meanwhile, the offense has never been higher than 13th in the Hazen era. The recent competitive seasons were fueled by the starting pitchers, and while the team’s recent struggles were shared by every subgroup of the club, the decline of the starting pitchers was particularly painful. The following chart shows the group’s fWAR by year, along with their rank among MLB:

So what happened? The front office couldn’t simply choose to extend its pitching staff like it did its offense. They were too talented. Patrick Corbin went on to sign a six-year, $140MM deal with Washington, Zack Greinke’s contract was already worth over $30MM a year, and Robbie Ray wouldn’t have been cheap to extend at the time. Keeping that trio together wasn’t in the budget.

Nor would such a move have been wise. While the trio put up a combined 11.2 fWAR in 2017, they only put up 5.4 fWAR this season, despite Robbie Ray winning the AL Cy Young. Decline was inevitable. The question wasn’t about how to avoid it, but how to replace their star-studded group with another. 

This was clearly the focus of the front office’s concern. Most of their resources have been spent trying to infuse new talent into the rotation. Since Hazen arrived, the team has added Taijuan Walker, Luke Weaver, Zac Gallen, Merrill Kelly, and Madison Bumgarner. The club has paid some notable prices for these pitchers. Walker arrived with Ketel Marte in exchange for Mitch Haniger and Jean Segura, Gallen was acquired for their top prospect (at the time) Jazz Chisholm, and Madison Bumgarner’s contract is by far the team’s largest.

All of these acquisitions flashed incredible potential. Weaver, Kelly, and Gallen all have shown moments of brilliance on the field, Bumgarner is a respected former ace in his own right, and Walker posted arguably his career’s best season in 2017. But ultimately, much of that potential has not actualized in the desert. As things stand, Gallen belongs near the top of a rotation, and Kelly and Bumgarner are respectable mid-rotation options. Injuries, however, hampered those three this year. Walker’s elbow went under the knife twice before departing the desert, and Weaver—after his own Tommy John Surgery—hasn’t been able to reestablish himself as a starter.

The D-backs also expected some production from their farm system. Jon Duplantier showed potential as a mid-rotation starter, and both Taylor Clarke and Taylor Widener were seen as back-end options. Since then, Duplantier and Clarke haven’t been able to hold down spots with the D-backs and have landed deals with other teams. Widener was able to survive 13 starts this year but will compete for a long-term home in the bullpen.

The club didn’t need all of these options to work out, but the production the team has received is not proportional to the amount of resources they’ve invested. What does it actually take to be one of the better rotations in the league? An ace and four respectable arms behind him. That alone will put you in the top ten. Of course, every team should expect an injury or two, but teams can often find a breakout arm to fill a hole. Having a second ace helps cover for any major injury and boosts the rotation’s upside. 

For the D-backs, arriving at this level would require any two pitchers among Weaver, Duplantier, Clarke, Widener, and Walker to provide league average production and for any pitcher not named Gallen to also post significantly more impressive results. Given the promise, that expectation wasn’t particularly unreasonable. Perhaps it would be more realistic to come up an arm short, but that’s a fixable problem. Coming up this short shows a clear failure to execute with the resources the team had, and one that has to raise questions about the team’s pitching development.

These concerns aren’t merely a prism to view the past; their pitching development is crucial for the club’s future. The arm-portion of the D-backs’ farm made major leaps this year and added much needed balance to a hitter-heavy system. A flurry of prospects with chances to stick in the middle or back of the rotation will debut over the next two seasons. The promise of Luke Weaver is also still around, but he’s already in his second year of arbitration. The clock is ticking. The D-backs can win with only modest success from their upcoming young arms, but such a failure would require excellent investments in free agency and trades. With 29 other teams (theoretically) trying to do the same, that won’t be easy.

This makes the hiring of pitching coach Brent Strom so important. Strom spent the past eight years as the pitching coach with the Astros organization, a club that is known for its ability to improve and develop arms. It’s difficult to ascertain the effect he can bring to a franchise by himself, but his hiring at least provides optimism that the starters will find their footing.

The D-backs’ rotation, once a crown jewel on the postseason club’s crown, fell swiftly. The club focused on accumulating promising talent to fill the rotation, but the project came up incomplete. In 2020 and 2021, the starters were rated one of the five worst such groups. As the organization enters its accidental rebuild, pitching development is going to be a focus. Fortunately, the hiring of Brent Strom as pitching coach gives hope for a revamped rotation once again leading the Snakes, but whether that potential will actually blossom remains to be seen.