Why the Marlins bullpen is among the best in baseball

Going into the season, the Miami Marlins bullpen was seen as one of the strengths of the ball club. Through 72 games, that has proven to be the case, even though injuries have taken their toll and some pitchers are taken on different roles than originally planned.

Following the team's fourth straight series win, this time against the Pittsburgh Pirates, the Marlins bullpen has a 3.49 ERA (eighth in MLB), 3.67 FIP (fourth), 9.73 K/9 (fourth) and 4.49 BB/9 (23rd). In the month of June, where they are 10-2, the bullpen has a 2.81 ERA, 2.99 FIP, 11.25 K/9 and 4.50 BB/9. Their win streak was snapped at six games on Saturday against the Pirates.

"They throw really, really good stuff," said bullpen coach Brandon Mann. "They have stuff that they can compete in the zone with, and I think you see that we get a lot of swing-and-miss out of our guys. We attack guys early and we try to get punchies when we have advantage counts."

One of the most lethal individual pitches this year has been Anthony Bender's sweeper (plus-9 run value). It currently grades out as the second-best sweeper in baseball, behind Shohei Ohtani (plus-11), and easily the best amongst all relief pitchers.

Bender's sweeper has 19.9 inches of horizontal break on average. Last year, it had 16.8 inches of horizontal break. The Major League Baseball average for sweepers in 2026 is 14.6 inches, per FanGraphs.

It wasn't all sunshine a rainbows for Bender in 2026, as in his first 10 appearances of the season were rough. Along with a 7.56 ERA, he blew two games, walked eight hitters and surrendered seven runs. The only positive was that he had a 3.83 FIP in that span, meaning he was running into some bad luck.

In his next 20 games, he has a 1.29 ERA, 2.01 FIP and has struck out 24 hitters and only walked three. Overall, Bender now has a 3.07 ERA, 2.53 FIP, 11.05 K/9 (career-high) and 3.38 BB/9 in 30 appearances.

Lake Bachar, who the Marlins claimed off waivers from the San Diego Padres in the midst of the 2024 season, has been one of the most crucial pieces of the bullpen. With injuries in the starting rotation, Bachar has had to start three of the Marlins bullpen games. In his first two starts, he has been perfect, going 5 ⅔ innings, striking out six in the process. On Saturday against the Pittsburgh Pirates, Bachar went two innings, allowing one run on one hit, walked one and struck out four.

"It’s not out of the realm possibility to see someone like Lake continue to get stretched out because he has shown he’s got a lot of weapons that can go through a lineup a couple of times," Marlins manager Clayton McCullough told reporters in Pittsburgh about Bachar.

Bachar's pitch mix isn't typical of a reliever, as he has six pitches in his arsenal, but all of them have been either at league average, or above that in terms of run value. His two best pitches thus far have been the slider and sweeper, both sporting Run Values of three.

The slider has generated a 45.5% whiff rate and 45.7% PutAway rate, the highest of all his pitches and in his career. It is his also second most used pitched this season (24%).

One incorporation into his already extensive arsenal is a curveball, which he has thrown 12.6% of the time. In his start against the Pirates, Bachar threw it 21% of the time, generating two whiffs, but did not strike anyone out with that pitch. Overall, the curveball has a 38.7% whiff rate rate and 27.6% PutAway rate. It has a Run Value of one.

Bachar also added a two-seamer, which is also known as a sinker to his arsenal. The first time he threw it in game was in his second start of the season, which came against the Tampa Bay Rays. He threw it 13% of the time in that start, only using it against right-handed hitters. In three appearances (two starts) using the sinker, he's only thrown is 11 times (1.8%), his least used pitch, but has a 20% whiff rate, but hasn't struck anyone out with it yet.

"It graded out as his best pitch (on Saturday)," Mann said the day after his start against Tampa. "Being able to bring something new into the mix, now he has more of an east-west profile and a north-south that profile really opens up more opportunities for Bachar to face lefties and righties."

In 22 appearances (three starts), Bachar has a 3.05 ERA, 3.70 FIP, 10.57 K/9 and 3.05 BB/9. It is uncertain wether Bachar will continue to be the Marlins starter when they have a bullpen game, but he certainly has given the team quality innings and length to save the overall bullpen a little bit more.

When the Marlins signed lefty John King to a one-year deal, they expected him to be used in certain pockets that they didn't have the luxury of using a left-handed pitcher in last season because they only had one. Early in the season, King was exactly that. In his first 10 appearances, King posted a 1.04 ERA, but 4.61 FIP. Since then, he has a 3.10 ERA and 3.99 FIP.

In the bullpen games, King has already had to make one start, which came in Queens against the New York Mets. For the most part, King continues to be used in certain pockets, but his usage has gone up, leading the Marlins with 31 games pitched this season.

King's secondaries weren't very good in 2025, so he is throwing them less and relying more on his sinker (plus-3 RV) and slider (plus-1 RV). The sinker (32.3% usage rate) has generated a 22.4% whiff rate and 27.6% PutAway rate.

Although it is his third most used pitch, King's changeup is getting the most whiff (33.3%) and his sweeper, the fourth most used pitch and new to his arsenal, is putting hitters way the most (25%).

After struggling against right-handed hitters in 2025, he is now dominating them, as they are slashing .152/.250/.239/.489 with one home run in 52 plate appearances.

Fish On First spoke to King early in the season and after meetings with the pitching staff in the organization, they cut down his sinker usage (now at 32.3%) and bumped up his slider and sweeper usage.

In 31 appearances, King has a 2.48 ERA, 4.17 FIP, 6.83 K/9 and 2.48 BB/9. His high FIP is due to his hard-hit% ranking in the 85th percentile, barrel percentage going up from 5.1% in 2025 to 8.1% Hitters overall are just able to attack King more, but his high ground ball rate and strong defense behind him have allowed him to find success in 2026.

The final name we will dive into is closer Pete Fairbanks. It's been mixed results so far for the $13M man. The Marlins have made it clear that they will avoid using the flamethrower in any situation where the team is down. If they are tied or leading in a game that falls under a save situation (winning by three or less), Fairbanks will go out there. He has been used in the ninth inning in all but one situation this season.

Fairbanks has a 6.75 ERA, 4.75 FIP, 13.05 K/9, 4.95 BB/9 and nine saves in 22 appearances this season. He did land on the injured list just one time this season, but the overall lower usage rate has been because of the situations Miami is looking to use him in. In his most recent appearance, which came in a save situation against the Pirates, Fairbanks surrendered one home run, but struck out two in the process.

"I think he's trending," Mann said. "I think the the numbers don't necessarily match up with with how I think he's personally pitched. I know his ERA versus his xERA is very, very different. He's punching out guys at a very high clip...He goes the next 17 innings and givea up one run, we're talking about how great Pete's been. I think he is trending in that that way."

The cutter which showed good results towards the end of the 2025 season and throughout all of spring training, it has a negative Run Value. The pitch has generated a 31.4% whiff rate and 17.4% PutAway rate. The slider, which he is throwing 18.6% of the time in 2026, has been his best PutAway pitch (34.6%).

After plenty of doubts on a low strikeout rate the previous two seasons, his 13.05 K/9 is the highest its been since the 2023 season (13.50).

Other names who have made an impact is Michael Petersen, who in 27 appearances has a 3.07 ERA, 2.76 FIP, 10.43 K/9 and 3.99 BB/9. The recently called up William Kempner has a 0.00 ERA, 1.60 FIP, 10.80 K/9 and 2.70 BB/9 in five appearances. Kempner has been used in more lower-leverage situations, but has thrived thus far.

Overall, the bullpen has some nasty stuff, proving to be strikeout machines, but their sustainability is in question if the Marlins continue to rely on bullpen games every fifth day. Also, the group's high walk rate will eventually come back to bite them if it is not addressed. For now, it is worth admiring how good they have been.