Comparing D-backs Preseason Projections to Current Results

The position players have outperformed projections while the pitching has underperformed. But by how much and how can we best measure it is answered here

D-Backs manager, Torey Lovullo, right, talks with pitching coach, Brent Strom, while Humberto Castellanos, left, walks past at Salt River Fields at Talking Stick on March 11, 2022 in Scottsdale, Arizona. Mlb Baseball Returns / Mark Henle/The Republic / USA TODAY NETWORK

The Arizona Diamondbacks have ridden a high octane offense coupled with solid defense to a winning record and playoff contention in 2024. That offense has also had to overcome a pitching staff that has performed well below expectations as whole.

We can see this in simple stats such as runs scored per game and runs allowed and ERA. The Diamondbacks lead MLB with 5.38 runs scored per game. But they rank 27th in both runs allowed and ERA, 4.83 and 4.60 respectively.

I thought it would be interesting to see how good a job WAR was doing at tracking and recording the relative performance of the team.

On December 8th, 2023 I posted an article with a chart detailing the projected WAR and payroll for the Diamondbacks. That was a snapshot in time, and was before the Joc Pederson and Jordan Montgomery signings.

The position player total was 22.1 WAR and the Pitcher total was 13.9, adding up to 36 WAR. Once you add in 48 replacement wins, the projected win total at that moment was 84.

Subsequently the team signed Pederson and Montgomery, adding at least one WAR to each part of the projection, so roughly 23 position player WAR and 15 pitcher WAR. That totaled a solid 86 win projection. At that point the split between position player WAR AND Pitchers WAR was projected to be roughly 60/40

As of this moment the Diamondbacks have a 79-64 record. Their .552 Win % is a pace for 89 wins. The total WAR produced to date comes out to 37 aWAR, which is the average of Baseball Reference and Fangraphs. The Prorated replacement for 143 games played is 42. Adding 37 to 42 totals 79, wins, which is the exact same total as the actual number of wins.

So far so good. WAR has done an accurate job of measuring team and individual performance. What we can also see in the table below is the spread between the batting and pitching tracks with the top line runs scored and runs allowed numbers presented at the beginning of the article. Instead of a 60/40 split in value, that has become a yawning gap of 77/23. Once again, this passes the "smell test"

D-backs WAR Breakdown / Jack Sommers

The reasons for the underperformance in the pitching staff have been discussed frequently on the pages of this website and elsewhere. Two veteran starters, Merrill Kelly and Eduardo Rodriguez, missed four months of the season. Their innings went to mostly replacment level pitchers that didn't perform well such as Tommy Henry and Slade Cecconi. The exception to that was Ryne Nelson, who has had a spectacular second half.

At the same time Jordan Montgomery never found his footing after missing spring training, and pitched so poorly he ended up in the bullpen as a mop up reliever. He has an ERA of 6.43. Rodriguez has an ERA of 5.83 in six starts since coming back and has not provided the boost the team was hoping for. Kelly has a 4.08 ERA and appears to have turned the corner.

Zac Gallen has not performed up to his past standards perhaps, but it's notable that his current 3.69 ERA exactly matches his pre season projection of 3.70 according to Fangraphs Depth Charts. The team's underperformance relative to pitching projections has little to do with Gallen.

In the bullpen, the primary cause of the problems has been Paul Sewalds collapse. He showed decreased velocity in spring training, then suffered an oblique injury, causing him to miss the first six weeks of the season. He was excellent through the end of June however, recording 11 saves and a 0.54 ERA.

Then it all fell apart, with three straight blown saves to begin July. He managed to shakily right his ship for a spell, but inability to locate his fastball caught up to him. He's posted a 6.95 ERA since July 2nd, and ended up losing his closer's job to Justin Martinez.

The cascade effect here has been to make it much more difficult for Torey Lovullo to manage workloads in the bullpen. With Sewald and Montgomery both relegated to mop up or low leverage roles, the wear and tear on the other relievers is starting to show. They are being asked to throw too many innings, and it's simply catching up.

The Arizona Diamondbacks are still clinging tenuously to a playoff spot by the slimmest of margins, 1.5 games over the Atlanta Braves for the final Wild Card position. The Braves hold the tie-breaker however, so the D-backs must finish one game ahead.

The team ERA through the end of August was 4.49. Over their last seven games they've posted a 6.90 ERA. They're fortunate to have a 3-4 record for the month.

Brent Strom and Torey Lovullo will need to figure out a way to manage the staff over the final 19 games and get the most out of them if the team is to remain in the Postseason picture.