Clowns in the Bullpen

I admit this one got away from me. I started doing the research for this post last week in anticipation of posting it last Friday and then I dug deeper and dug deeper and next thing I know it’s another week later and I finally have a post. Luckily (?) the Nationals bullpen did not take advantage of my delay by suddenly being good.

There are a lot of factors at play here but the first is obviously the personnel. If you are like me, you did not pay a huge amount of attention to who was in and out of the bullpen over the offseason. All I tracked was that it was a lot of names of guys I didn’t know, but the Nationals rode that formula to decent success last year with their best bullpen since 2016 by FanGraphs WAR. There were some rumblings from the folks who followed spring training games that something was wrong, but probably like most of you, I didn’t see how bad things were until the season started.

So, let’s revisit those offseason moves. To start, here are the five best relief pitchers by fWAR for the 2024 Nationals and their fate:

College football writer Bill Connelly tracks a concept called “returning production” in an attempt to help spot teams that could overperform previous seasons through the magic of experienced players. In this case, while the Nationals have five relievers who pitched for them in both 2024 and 2025, they only represent 22 percent of the total innings pitched in 2024. That’s not a great start.

To make matters worse, the pitchers the Nats brought in this offseason are even worse than the guys who hung around. Lucas Sims, Jorge López and Colin Poche all have a negative fWAR and the three worse ERAs in the bullpen. That bad news is made worse by the fact that there’s nothing really in their history that suggests they should be playing better. For example, let’s compare this trio to the trio of departed relievers from 2024 Garcia, Floro and Harvey by good (>= 1 win) and bad (< 0 wins) seasons.

So, Rizzo managed to take an unknown but effective group and almost perfectly mirror it into an unknown but terrible group. Sims, López and Poche are so bad they make Garcia, Floro and Harvey look like they’re the law firm of Kintzler, Madson and Doolittle.

You might remember though that there were four relievers from 2024 that are not in the bullpen this year, not three, so what of Derek Law? Well as his stunning 90 innings pitched in 75 appearances (2^nd and 1^st most for the Nats since 2018) show, he is just the latest in a line of relief pitchers ruined by the management stylings of Davey Martinez.

When Kyle Finnegan pitched on zero days rest in two consecutive games in early April as Davey pushed to get some morale-boosting wins against the Los Angeles Dodgers it inspired a question: who lead the league in relief pitcher appearances on zero days rest since Davey Martinez has been the Nats manager?

Yes, it’s your Washington Nationals, by a whopping 42 appearances more than second place. The gap between the Nationals and Giants is exactly equal to the gap from the Nationals to the Rays. It should be no surprise that on a year-to-year basis the Nationals have been top 5 in MLB in appearances on zero days rest every season since 2018 except 2022 (7^th) and 2023 (22^nd).

But all appearances are not equal, what if we look at appearances on zero days rest where the pitcher also threw at least 20 pitches, a level which leads to an amplified dip in velocity in subsequent games according to Kyle Burris and Jacob Coleman?

Yes, the Nationals are still the leaders, and this time the gap between them and second place is about equal to the gap from second to the 11^th place Chicago Cubs (148). Concerningly the “smart” teams that showed up in the previous table (Dodgers, Rays) have also disappeared here. This leaderboard is a murder’s row of some of the worst front offices in baseball.

However, that is still a measure based on zero days rest so what about other ways to try to measure overuse? I came up with another simple metric to attempt to capture inefficient bullpen use, innings pitched by relievers divided by total number of appearances. By this metric teams with a lower number are more inefficient because they use more pitchers to get an out. I’ve dubbed it Reliever Usage Efficiency or RUE because a team will rue using their pitchers inefficiently.

Yes, yet again the winners are your Washington Nationals. At least this time the gap between them and the next worst teams is not as large as the previous tables. Going by individual seasons, the news gets worse as the Nationals are the only team with three seasons with a RUE below 1, that is they had more reliver appearances than innings pitched, in 2018, 2019 and 2021.

And after nearly a thousand words we get to the part of the article that has delayed me for a week. Because while it seems like common sense that having too many appearances on zero days rest, too many of those with 20+ pitches and overall inefficient use of pitchers is bad, I don’t like to deal with common sense, I want to show actual negative effects with data. And that is surprisingly hard to do.

First, I looked at the correlation between appearances with zero days rest and bullpen ERA, FIP, fWAR, and win probability added (WPA) by team and year and found nothing of significance. Then I checked the same metrics against RUE and also found nothing of significance.

When I struck out there, I pivoted from comparing effectiveness to comparing exhaustion as measured by their velocity and spin rate on their fastball on zero days rest, one day rest and two days rest. The table below shows the average and median decrease in fastball velocity and spin rate by a relief pitcher on zero days rest versus the same pitcher on one, two and three days rest. The pool of relief pitchers was limited to those who threw at least 450 pitches.

While there is a small difference here it is not a lot. That does make some sense, the pitchers that are most likely to be overused are the best ones on the team. The negative impact of overuse might not be effectiveness as much as it is availability, as illustrated by Law and other Davey favorites like Sean Doolittle, Tanner Rainey, Harvey, and Wander Suero quickly going from overuse to long term injury.

I used FanGraphs’ injury tracker to look at relief pitcher IL stints from 2022-2024 but again came up empty with little correlation at the team level. While it’s certainly possible if you look at the individual level to determine whether overuse as measured by appearances on zero days rest and RUE lead to a higher chance of injury, that will have to be research for another day.

I think while appearances on zero days rest and RUE are easy to understand they are unfortunately not sufficiently complex to accurately capture relief pitcher overuse and its impact on performance. I will leave it up to you to decide whether that let’s Davey off the hook or not and how mad you are that I just wasted your time reading all that (don’t worry I wasted way more of my own). To me they still look like flashing red warning signs that require further inspection. All this to say that by many measures the 2025 Nationals bullpen is a bare cupboard operated by an incompetent chef which would look a little something like this.