The backend of the ‘pen was as good as any in the game. So why was our bullpen so bad last year?
When a team finishes a tie-breaker shy of the playoffs, the blame can go anywhere. The result of a single ballgame – perhaps hinging on the outcome of a single inning, a single at-bat, a single pitch – going differently than it did would have changed the Diamondbacks 2024 season outcome. It can be maddening that after 162 games, the margin for error would be so small that events as small as a single pitch could be the difference between who plays October baseball and who gets an early start on the offseason. If you dwell on it too long, trying to hyper-analyze every pitch that could have gone differently, you would probably go insane. It’s just too much.
Instead of trying to drill down to an individual moment out of 6 months of moments that occur in a regular season, I want to look at one of the overarching aspects of the Diamondbacks’ season that can be viewed as a prime point of failure: the bullpen.
There was some consternation in the fanbase coming into the 2024 season about Mike Hazen’s lack of additions to the bullpen during the offseason. Personally, of all the places that needed attention, the bullpen was the lowest of priorities to me and I agreed with Hazen’s plan of going after players to bolster the lineup and starting pitching, arguably our weakest and thinnest spots during the playoff run. Without Guggenheim-levels of resources, Hazen will always have to pick and choose what areas he can improve and what areas he just has to let ride. While Hazen’s bet on the bats came through in spades, his starting rotation crumbled, which resulted in a taxed bullpen by the end of September which ultimately cost us a playoff spot.
I tried looking at several different metrics and groupings to see how the Diamondbacks’ bullpen came up short compared to their counterparts, and I stumbled on something that I think can probably be viewed as the root cause of last year’s bullpen failure: The Others.
I’d like to take a tangent into basketball to explain what I mean by Others. In basketball playoff series, TNT’s postgame analysis crew, headlined by Charles Barkley and Shaquille O’Neal, usually falls back on a particular line of analysis to determine who will win a specific series. They expect the stars on both teams to play well and probably cancel each other out. When that happens, they say, the series will come down to which team’s “Others”, or role players, answer the bell. Quite often, the postmortem of a basketball playoff series can be as simple as looking at which team’s 4th-7th best players outplayed their opponent. In that same vein, we can divide MLB bullpens into two groups. Commonly, we call it the A-bullpen and B-bullpen, but I’m going to rename the groups to Stalwarts and Others for this study.
To define who is on the list of a bullpen’s Others, I settled on a mostly arbitrary cutoff line of 50 IP. If a player logged above 50 IP, he was a reliable contributor whose manager was comfortable going to him frequently during the marathon of the season. As I looked at different bullpens around the league, most had between 4-6 pitchers who surpassed that threshold. Having 4-6 pitchers that can go out there for a whole season and contribute may seem like a high percentage as most teams have an 8-man bullpen on any given day, but in reality, nearly all teams will use at least 20 different pitchers as relievers during a season and many will use closer to 30 arms out of the bullpen! What I found was that how teams can fill in those other 15-25 arms (and anywhere from 45-55% of their total relief innings) can be the difference between making the playoffs and not.
The Diamondbacks bullpen finished in the bottom fifth of MLB bullpens in ERA and FIP with marks of 4.41 and 4.19 respectively. Breaking down the difference in the bullpen between the Stalwarts and the Others provides a striking contrast. D-back Stalwarts in 2024 were J-Mart, Ginkel, Thompson, Jarvis, and Mantiply. All five pitched at least 58 innings while none of the 22 other players with at least one appearance in relief tallied more than 40 innings. The Stalwarts pitched to a stellar 3.17 ERA combined on the year. That top end goes toe-to-toe with any other bullpen in baseball. The Brewers, for instance, fielded the 2nd-best bullpen by ERA this past season, and their Stalwarts pitched to a 3.15 ERA. Our competition for runner-up in the NL West, the San Diego Padres, finished the year with a Top-10 bullpen, and their Stalwart ERA was 3.07. The difference in these three teams’ relief pitcher rankings came down to the Others. The Brewers’ Others rocked an outstanding 3.05 ERA. The Padres’ Others had a less remarkable, but not ship sinking, ERA of 4.34. The D-backs Others? They recorded an absolute dumpster fire of a year at a 5.79 ERA.
If we had a top flight backend of the bullpen which accounted for about 55% of our total relief innings, how can I blame the Others for our bullpen’s failure? Without pointing to any specific games, I can spin a yarn on how the typical game went for the Diamondbacks. The offense would jump out to an early lead, and usually a fairly sizable one. The starting pitcher wouldn’t be able to soak up a ton of innings, so Torey would turn to the Others to try and close out the game. Time and again, the Others would let the other team slowly eat away at the lead, turning a sizable lead into a Save Opportunity, requiring Torey to bring in the A-bullpen to close out more games than we’d otherwise hope. By the end of the year, the A-bullpen was so worn out that it wasn’t all that surprising Diamondbacks relievers had the highest ERA of any team in the month of September.
Take a look at the numbers of some of the more notable Others we employed last season:
The first things that jump out to me from the above table are our Trade Deadline acquisitions, which couldn’t have turned out more differently. AJ Puk was a roaring success and will likely be among our Stalwarts for the next two seasons, but as good as Puk was, Dylan Floro was just as bad. It’s inexplicable how he went from having the best season of his career pre-trade to September being the worst month he’s ever pitched. I can’t blame Hazen on that one. The next thing that stuck out was all the veterans, either already on the roster or picked up on minor league deals before the season, that didn’t work out. McGough, Hughes, Allen, and Castro all pitched to no better than a 5.46 ERA. The only ‘flyer’ that worked out according to ERA was Thyago Vieira, but his FIP was 2 runs higher than his ERA and was more the benefit of luck than skill when it came to his final numbers.
In total, the Diamondbacks had only 5 out of 22 Others with an ERA under 4 (including Pavin Smith!). That’s a pretty horrendous mark considering the Brewers had 17 out of 23 Others with an ERA under that line. The Padres only had 20 players pitch in relief this year, with 4 qualifying as Stalwarts, but they had nearly half of their Others (7/16) pitch to better than a 4 ERA.
Alright, so our Others were brutally bad in 2024. What can Mike Hazen do to fix it for 2025? My honest answer is I don’t know. I would have no problem with Hazen spending big at the top of the free-agent reliever market. That lengthens the pool of potential Stalwarts and helps lessen the load expected for the Others, but relievers are a volatile lot and it may be safer to put our finite resources into safer investments. Really, the best way to fix our Others problem would be to have a stream of young relievers ready to fill in from Reno, but that isn’t a single offseason fix.
Between J-Mart, Puk, Ginkel, and Thompson I believe the D-backs have a group of four horses that will be able to carry their water and go toe-to-toe with any other ‘pen in MLB. The big question for how the Diamondbacks bullpen shakes out will be how the Others fare. Who will step up when the injury bug bites? Will Drey Jameson be ready to produce in a meaningful way coming off TJ? Will Bryce Jarvis and Joe Mantiply be able to reprise their roles as Stalwarts? Will the minor leagues produce anything useful in 2025, a la Andrew Saalfrank’s 2023 season? Will the NRIs that Hazen grabs off the lower rungs of the free agent market produce or will they be more fodder on the scrap heap of D-backs bullpen history?
What do you all think? How do you want to address our Others problem in the bullpen? Do you want to go after some bullpen help on the free-agent market? Do any of you have eyes on a particular farmhand who may be able to make an impact next year? Perhaps you believe our starting pitching will bounce back to the mean compared to last year and relieve the burden on the bullpen, allowing everyone to flourish in their roles. Let us know in the comments!