On March 31st of this year I published an article Breaking Down The Diamondbacks Rotation. In that article I expressed a lot of concern about how badly the rotation projected. Early in the year we had some debates about which part of the pitching staff was trending worse, the rotation or the bullpen, and clearly the bullpen “won out” in those discussions. However the overall concerns turned out to be correct, and in some cases pretty accurate.
We know that at various points in the season, every one of the “original” starters has been either injured (or suspended). Actually, there is a gray area when defining “original” starters. Caleb Smith made the rotation as expected out of spring training, but got sent to the bullpen after only one start in favor of Taylor Widener. When Widener injured his groin, Smith rejoined the rotation, and even after Widener came back continued to receive starts here and there sandwiched around further demotions to the pen. However you want to slice it, the team traded for Smith midseason 2020 and intended for him to be a starting pitcher.
For the purposes of this article, I’ve decided to use “Original 6 Starting Pitchers” and just include both Smith and Widener. Removing Smith and putting him in with replacement starters seems disingenuous to me. Mike Hazen constructed the rotation this way, so that’s how I broke it out. Note I am just using some simple stats, nothing esoteric, as the point is made clearly by keeping it simple.
TEAM TOTAL BEFORE BREAKOUT
The first thing you will notice is the team has been exactly average in the number of innings pitched by starting pitchers. For all the handwringing, they are exactly average in how many innings they give to their starters in total. The team SP ERA is 1.10 runs higher than the average of the other 14 teams. That’s obviously very bad. It’s a major reason the team was so bad this season. The Run Support is well below average, ranking just 12th best in MLB, and the 3 teams behind them in run support all play in pitchers ballparks, (New York, Miami, & Pittsburgh). Tack on the worst or 2nd worst bullpen in the league and poor defense and it’s no wonder they are 48-103. O.K., you say, but all our starters were hurt at some point. That’s true. But let’s look at what they did when they were here.
ORIGINAL 6 Starting Pitchers
So the original 6 have still made 72% of the starts for the D-backs. I didn’t go through every other NL team but one can do so themselves if they like via this report. All teams have injuries, and if one were to go team by team, they are going to find very few teams with over 85% of their starts going to the original intended starting pitchers from their spring training depth charts. And some teams have lost a lot of big name , big dollar pitchers.
Regardless, what is painfully obvious is even you compare our Original 6 to the overall league average, which contains all the replacement pitchers as well, the D-backs top starters have an ERA. .60 runs higher than the league average. With the exception of Smith it’s not ”tire fire” bad. He does indeed bring down the numbers. But the other 5 guys are all between 92-96 ERA+. Nobody is over 100. The team W-L % in games started by the original 6 is .343. That’s still below the .350 W% threshold I used when writing the article on team turnarounds , and it actually looks worse when you take Smith out of the picture as the team was 6-7 in his starts. So any way you slice it, the performance of even our best 6 starters was well below average to begin with and the original concerns stated at the beginning of the year were justified.
A word about Zac Gallen’s 4-17 team WL record: The only starter with lower run support has been Caleb Smith. Also of note Gallen has allowed 7 Un Earned Runs. That’s by far the most among starting pitchers. Bumgarner has allowed 4, no other starter has allowed more than 2. So while Zac’s season has been a disappointment, we can at least be comforted by the fact that he’s pitched into some bad luck. In addition, while I didn’t post the run predictor stats, in fact almost all of Zac’s predictors are about a half run lower than his ERA, and roughly around 4.00. That’s still higher than most expected perhaps, although pre season projections had him at 3.87 ERA. The best way to summarize his season is to say Zac has actually pitched to his projections, but gotten far worse results.
The other obvious question is how much did the injuries themselves impact the above stat lines. We know that in Bumgarner’s case he made at least two or three starts with his shoulder barking at him before he went on the IL. Gallen suffered two distinct injuries, the fractured elbow from spring training BP, and then a sore throwing elbow in a different area. In his case, based on reports and his own comments, he never pitched with any pain in MLB games, but getting ramped up shortened his initial outings back, and he was probably knocking off rust and struggling with command at least in part due to the stop and start nature of his season.
Widener’s ERA looks respectable, but his peripherals have always been 1-2 runs higher and it was predictable he would struggle. He’s healthy. It’s not the groin that’s the issue.
These are all excuses though. All teams have injuries, and all pitchers have aches and pains, and we can’t just hand wave away the poor performance of even these 6 guys due to injuries.
Well, it just doesn’t get any uglier or more disappointing than this. The one pitching prospect we were counting on the most to emerge, Corbin Martin, couldn’t have been any worse, and then he got injured again to boot. Our next best starting pitching prospect, Jon Duplantier , flamed out completely and was released. Out of 10 replacement starters the only ones that have halfway decent numbers in their limited starts are Tyler Gilbert and Humberto Castellanos. But let’s face it, neither have the stuff to truly stick in a decent MLB rotation. I don’t want to bag on either of them, but when your best performing replacement pitcher is a 27 year old rookie with a K rate under 6 and FIP and xFIP more than a run higher than ERA....well....just enjoy the moment he provided in his debut with the no hitter is my best advice.
While we hope the next crop of pitching prospects does better, it’s disturbing that the team couldn’t even gin up one guy that truly impressed, even if just for 4 or 5 starts.
As bad as the Diamondbacks starting pitching has been this year, taking my inspiration from Makikilo I’ll leave this on a positive note. In 2016 Robbie Ray, Zack Greinke, Zack Godley and Patrick Corbin all had sub par years, and each of them improved their ERA by leaps and bounds the very next year.
2016 Starting Pitchers vs. 2017 Starting Pitchers
So maybe Gallen, Madbum, Kelly, and Weaver can all do the same thing and some of the new prospects on the way that are in AA & AAA right now can contribute by filling in the 5th & 6th spots of the rotation competently.