When It Comes to Relievers, the Mets Sure Have a Type

Brad Penner-USA TODAY Sports

Last year’s Mets were a bit of a mess. After entering the season as a projected powerhouse, things fell apart quickly. They jettisoned their two highest-paid pitchers at the deadline for prospects and finished with a lackluster 75 wins. There were multiple reasons for such a disappointing season — their bats stalled and only one starting pitcher reached 130 innings — but perhaps no loss was more devastating than that of closer Edwin Díaz. Before the season, his injury dropped the Mets from second to 19th in projected bullpen WAR; they ended up 29th.

The Mets knew that Díaz would be back in 2024, but they still entered the offseason needing to improve a bullpen that way too often turned to the likes of Trevor Gott, Tommy Hunter, and Jeff Brigham. And in a wave of recent moves, they’ve done just that, signing Adam Ottavino, Jake Diekman, and Shintaro Fujinami to one-year deals.

One of these faces isn’t at all new to Queens. Ottavino initially signed a one-year deal with the Mets before the 2022 season and pitched well enough to re-sign on a two-year contract, with a player option after last season. In November, he opted out of that deal, hit free agency, and then, ultimately, returned on a deal that was worth less than the player option he declined a few months earlier. I wrote about Ottavino’s signing last offseason, and primarily focused on his return to dominance in 2022 after a couple inconsistent years. In that season, he had one of the best year-over-year improvements in K-BB% of any big league pitcher, as Herculean improvements to his sweeper command simultaneously led to more whiffs and fewer free passes. Last year, he was an outlier with his year-over-year K-BB% change again, though this time, he was on the more dubious side of the leaderboard.

Biggest K-BB% Fallers, 2022-23
Name K-BB% Loss
Andrew Heaney 15.2%
Carlos Rodón 13.5%
Collin McHugh 13.1%
Adam Ottavino 11.8%
Alek Manoah 11.6%
Chris Martin 11.6%
Alex Wood 10.7%
Carlos Carrasco 10.5%
Cristian Javier 10.2%
Luis Severino 9.5%
min. 50 innings each season

Ottavino’s walk rates returned to their previously high levels, while he struck out under a quarter of batters for the first time in a decade. Now 38 years old, part of this was just age catching up to him. Last year, his velocity dropped about a tick and a half on each of his pitches, and his sinker, sweeper, and changeup lost considerable horizontal movement. The rest of his woes came from worsening command. Ottavino missed spots more often with each pitch type, and this decline in arsenal synergy made him worse in nearly every plate discipline stat. These changes most prominently impacted the performance of his sweeper, his go-to offering to put hitters away. Its chase rate fell from an excellent 36.7% to a dreadful 23.2%, while its swinging strike rate was more than halved.

A silver lining of never throwing a strike is that your pitches are difficult to square up, and that fact is exactly why Ottavino remained effective despite not being a strikeout machine. For the third consecutive year, he ranked in the 90th percentile or higher in barrel avoidance thanks to his ability to coax so many ground balls and make batters uncomfortable with his cross-bodied delivery. His 3.55 xERA lines up much more nicely with his 3.21 ERA than does his 4.52 FIP, which perhaps unfairly led to his sub-replacement WAR figure for the year.

Ottavino continues to navigate the difficult task of getting outs without throwing strikes, and the same description can be assigned to his new teammate Diekman. The 37-year-old lefty has bounced from team to team, consistently sticking around because of his funky arm slot and solid strikeout rates. Last season got off to a disastrous start for Diekman, who was designated for assignment by the White Sox after a month in which he walked over one-fifth of the batters he faced. But the Rays scooped him up, applied their patented strategy of “See that pitch you have with a good run value? Throw it more!” and let his fastball do the talking. The guy who wasn’t good enough for the 2023 White Sox had a 2.18 ERA and 3.21 FIP the rest of the way, leading to the best season of his 30s.

With Tampa Bay, Diekman threw four-seam fastballs 61% of the time, by far the highest rate of his career. So what did the Rays see in that pitch that his previous employers didn’t? It’s actually less complicated than you might think. First, as a sidearmer, his pitches aren’t coming from a release point that batters are accustomed to seeing, and his fastball’s horizontal approach angle sat in the 91st percentile among left-handed pitchers. More importantly, he simply throws much harder than anyone else with a similar arm angle. Only seven pitchers had a horizontal release point of more than 3.5 feet, and Diekman stands in a league of his own in terms of fastball velocity.

Fastball Velocity Leaders, Sidearm Division
Name Velocity Horizontal Release Point (absolute value)
Jake Diekman 95.5 mph 4.02 feet
Michael Tonkin 93.5 mph 3.66 feet
Jose Cuas 92.7 mph 4.23 feet
Paul Sewald 92.2 mph 3.70 feet
Tim Hill 89.6 mph 3.89 feet
Hoby Milner 88.5 mph 4.32 feet
Tyler Rogers 82.8 mph 3.97 feet
SOURCE: Baseball Savant
min. 500 fastballs

Another change the Rays made to Diekman’s arsenal was the introduction of a changeup, which is not exactly a new pitch for him, but before last year, he had never thrown more than a handful of times in a season. In 2023, changeups comprised a quarter of his pitches thrown to right-handed batters. The pitch has solid characteristics; he throws it hard with considerable horizontal fade. He seldom used it late in counts and recorded just one strikeout with it. Still, it generated excellent results on contact, as hitters slugged below .300 against it. Despite his unique delivery, Diekman has never had significant platoon issues, but he was even better after adding a new weapon to keep righties at bay.

Diekman’s biggest flaw has always been control, and being effective while walking 13.3% of the batters he faces is a tightrope act that he’s so far executed to success. Pitchers who can neither throw strikes nor draw chases almost never stick around, but Diekman ranks in the fourth percentile or worse in both metrics and is entering his 13th season. That’s because when batters put the ball in play against him, it usually goes in one of two directions – straight up or straight down. Last year, he was among the league’s best at avoiding line drives, while his hard-hit rates and average exit velocity were nearly unparalleled.

Unlike Diekman and Ottavino, the last of New York’s new bullpen trio has some contact quality issues to navigate in addition to finding the strike zone. When Fujinami’s stuff is working, it’s easy to see why. His fastball touches triple digits with a good vertical approach angle and elite extension, and even if you catch up to it, good luck laying off his splitter. It is the second fastest pitch of its kind and absolutely falls off the table.

But his struggles with location have been known since his days in NPB, and in his rookie campaign, his effectiveness sometimes would disappear without warning. His inconsistency was on display in his MLB debut, when he had four strikeouts in the first two innings before allowing eight runs in the third, which he was unable to complete. After a few disastrous starts, Fujinami was moved to the bullpen, where he could better let his stuff play in short bursts. While his season ERA of 7.18 is quite alarming, his numbers after being moved out of the rotation cast a more favorable picture, with a 5.48 ERA and 3.99 FIP.

Fujinami’s command troubles often got in the way of his lights-out stuff. His fastball is a whiff machine at the top of the zone, but he was rarely able to land it there. And while his splitter is untouchable below the zone, he allowed three home runs with that pitch because he left those offerings over the middle of the plate. Just throwing strikes isn’t always synonymous with command, but Fujinami often struggled to execute the general plan that should fit his arsenal: fastball up, splitter down, cutter in. Of 179 qualified pitchers in 2023, he threw the 10th fewest percentage of pitches in the shadow and chase areas of the zone, meaning a disproportionate amount of balls out of his hand were headed either right over the plate or nowhere near it. At his best, Fujinami can out-stuff almost any hurler in the majors, but last season it was unclear which version of him you’d see on any given day — or in any given inning.

Mets Top Reliever ZiPS Projections
Name K% BB% FIP
Edwin Díaz 39.2% 8.1% 2.29
Brooks Raley 25.3% 10.1% 4.08
Adam Ottavino 24.3% 11.1% 4.12
Jake Diekman 26.5% 14.9% 4.48
Shintaro Fujinami 23.3% 14.4% 4.70
Drew Smith 24.7% 10.1% 4.56

With these signings, it’s clear the Mets have a type they’ve coveted in their relief acquisitions – pitchers with high walk rates who succeed via other means. After signing a barrage of large contracts over the past couple years, they’ve toned down the spending a bit this offseason. But these guys, along with the previously signed Jorge López and Phil Bickford, constitute a tremendous upgrade over last year’s relief group. Depth Charts now forecasts them with the 12th best bullpen in the majors. The Mets still have a ways to go before they can contend again, but at least for now, they’ve shored up an area of great need.

Kyle is a FanGraphs contributor who likes to write about unique players who aren't superstars. He likes multipositional catchers, dislikes fastballs, and wants to see the return of the 100-inning reliever. He's currently a college student studying math education, and wants to apply that experience to his writing by making sabermetrics more accessible to learn about. Previously, he's written for PitcherList using pitch data to bring analytical insight to pitcher GIFs and on his personal blog about the Angels.

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David Klein
2 months ago

I like the Diekman signing as the Rays seemed to fix him having him throwing the changeup more, but he’s still a walk machine. The Fujinami deal doesn’t have an assignment bonus so they can send him to the minors if he struggles so that’s a decent signing and he had a 3.94 e.r.a his last 40 or so outings. Not a fan of the Ottavino signing as his fip went up a decent amount, his walk rate went way up vs his 2022 numbers and his strike out rate dropped like a stone. and his chase rate vs his sweeper dropped from the mid 30’s in 2022 to the low 20’s in 2023.