The Nats Bullpen Gives the Opposite of Shame

The talk of the town for the last week has been the Washington Nationals bullpen and for once, it’s not because they’ve done something wrong. Like Bart Simpson when his dad became an astronaut, fans are feeling less shame when a reliever comes trotting out onto the mound. How did we get here?

As a certified Davey Martinez hater I was really hoping it was because he got fired, with further evidence of how terrible a bullpen manager he was. However, the stats do not back me up as the Nats had a 5.79 ERA and 4.94 FIP before he was fired (last in MLB) and a 4.84 ERA and 4.75 FIP after (24^th). That’s an improvement, but not the big one everyone is noticing now. And the usage rate has not gotten better, since Davey’s firing the Nats have had a reliever pitch on zero days rest 43 times (3^rd most in MLB).

No that seems to have come from the twin callup of Clayton Beeter and PJ Poulin on August 5^th. With the addition of two good relievers that Nats dropped to a 3.97 ERA (13^th in MLB) and have been on a tear lately, including 19 2/3 scoreless innings in a row. Yes, you read that right, the guy the Nats acquired for Amed Rosario and an August waiver pickup from the best team in the American League are the good relievers leading the charge. Beeter has a 2.30 ERA in 17 appearances and Poulin tops him with a 1.50 ERA in 19 (55% of the games he’s been here for).

Of course we’re dealing with some small sample sizes here, so it’s not time to hang the victory banner just yet. However, there are some measures we can turn to when the innings counts are low: StuffPro and PitchPro. Here we see some encouraging signs for future success as Beeter and Poulin manage to do something almost no other Nats reliever has done this year: throw good pitches. Below is a list of every Nats pitcher who has thrown at least 5 innings in relief and have an arsenal value (pitch run value multiplied by percentage of time thrown) below zero (good) by both StuffPro and PitchPro.

No surprise to find the two Nationals closers here, along with one of the pitchers they signed and traded three weeks later. Ferrer has been great lately too, with a 1.08 ERA in 15 games since Kyle Finnegan was traded. I know he had a 6.57 ERA but I’m still surprised López did not get picked up by somebody after the Nationals released him in May to make sure he did not just come down with Nats reliever disease. Instead, he serves with Ribalta as cautionary examples that good stuff in a small sample is not guaranteed success.

Which leads to the natural question of whether Beeter and Poulin can really keep this up. I’m seeing some encouraging signs that the answer is yes.

When Beeter moved to the bullpen full time in 2024 he tightened his arsenal to just two pitches, fastball and slider, and started throwing his slider 46 percent of the time. That’s a good thing because his slider is one of the best in baseball, grading out to the 95^th percentile by Robert Orr’s Pitch Quality which is a combination of its ability to miss bats and suppress damage on contact. His fastball does not grade out as well, but I think he has room for improvement since he averages 96 MPH and gets 18 inches of induced vertical break (IVB), but has a pretty normal vertical approach angle of -4.7 degrees. If Beeter can move his fastball location up in the zone to take better advantage of his IVB he can really make that slider shine.

Poulin on the other hand mixes four pitches, mainly throwing fastball + changeup to righties and fastball + sweeper to lefties. He gets most of his value out of his sidearm throwing motion that keeps hitters on their toes with drastic changes in horizontal movement. With such drastic differences in lefty and righty hitter approaches Poulin is like two different pitchers depending on the batter. For righties the name of the game is weak contact with his fastball and changeup both in the 70^th percentile by damage suppression. For lefties, he’s going for swing-and-miss, with his sweeper having a 46 percent expected whiff rate. Like Beeter, Poulin needs to work on keeping his fastball up in the zone, his sidearm delivery gives him an elite -4.1 degree vertical approach angle, but he throws it mostly in the middle of the strike zone, negating his potential advantage.

While Beeter and Poulin finally give us some relievers that manage to clear the low bars of mildly interesting and maybe worth keeping around next year, there’s one other thing that is probably what’s really behind the sudden bullpen improvement, the game is over by the time they enter.

From the start of the season until Davey was fired the average leverage index when a Nats reliever entered the game was 0.96, essentially average. Since Davey was fired, their average leverage index when entering the game is 0.78, well below FanGraphs’ threshold for a low leverage situation. In other words, since Davey was fired, the Nats starters have been so bad that Nats relievers are almost guaranteed to be pitching in a blowout. It’s a lot easier to be an effective pitcher when the opposing batters don’t feel any pressure to perform.