JB's Bullpen Method Strategy for 2025: Making FrankenAces Out of Relief Pitchers

March 13, 2025

Nick explains how to win 2025 fantasy baseball leagues using relief pitchers to build pitching aces. He uses JB’s bullpen method to recommend relievers to draft.

Five years ago, the inimitable JB Branson published an article breaking down his favorite fantasy baseball strategy that he’s deployed for over a decade. In his words, the Bullpen Method is a lifestyle that reflects the importance of balance on a fantasy team. That turned into an annual Bullpen Method article, with the 2023 version nominated for the FSWA's Baseball Article Of The Year award. I'm here to carry the torch forward, with this being my second year coming out of the 'pen.

You need a steady and consistent balance, which means deviating from the traditional over-reliance on starting pitchers. One winds up relying on pure volume for wins and strikeouts while often yielding ERA and WHIP, unless you go SP-SP early and struggle offensively. There are a precious few SPs beyond the first five rounds to trust with one's ERA and WHIP, and most are clamoring for their services.

The opportunity cost of a roster spot on RPs is worth it, especially when most of these picks come late! We encourage you to give the bullpen method a shot before your 2025 fantasy baseball draft. Given our track record discussing this, I am going to link last year's article that dives deep into historical use cases while focusing more on the 2025 approach here.

Breaking Down JB's Bullpen Method

In a standard league, one will roster 11-13 pitchers. Of those, five or six will be starters. This leaves seven or eight relief pitchers, and one shouldn’t care if they are preseason “closers.” For years, Dellin Betances and Andrew Miller were anchors, then Josh Hader emerged before taking the closer role, and every year, a new crop of setup studs emerges. Devin Williams in 2020, Jonathan Loaisiga (2021), Jhoan Duran (2022), Bryan Abreu (2023), and Cade Smith (2024).

This is the Bullpen mentality, realizing that starting pitchers are heavily overrated in fantasy and, subsequently, relief pitchers (especially setup men) are heavily underrated. Once you come to this epiphany, you can immediately take advantage of this blind spot and zoom ahead.

*Disclaimer - Please do not attempt this method in Points Leagues. Points leagues are made for heavy-volume starters and elite closers. This method crushes Roto leagues, where balance is king, and in H2H leagues, where you can easily beat your opponent in three of the five pitching categories (all five if you are a talented SP streamer).

Building FrankenAce Relievers

The first question most people ask when they see my drafts is, "How can you win without drafting aces?" Well, there are two answers. First, draft the sleepers that become aces. Easy, right? The second and most important answer is that YOU BUILD THEM WITH RELIEVERS.

Like Frankenstein, you can put together a stud ace with unwanted scraps you find on the waiver wire or late in the draft. This is the heart of the Bullpen Method. (Aaron Bummer and Drew Pomeranz will always have a place in our hearts and on the FrankenAce logo.)

Past FrankenAces

Yours truly crushed the RotoBaller Expert League in 2020 thanks to the "Willianthal" FrankenAce built by two undrafted relievers: Devin Williams and Trevor Rosenthal. They produced a line of Five W, 91 K, 1.07 ERA, and a 0.73 WHIP.

Now, let's compare the stats of 2020 fantasy golden boy Lucas Giolito: Four W, 97 K, 3.48 ERA, and a 1.04 WHIP. Thanks to Rosenthal's 11 saves, undrafted Willianthal FrankenAce just beat Gioltio in four of five categories, losing strikeouts by only six.

The 2021 FrankenAce Award went to JB for combining his 432rd overall pick in TGFBI with a waiver wire add in Chad Green and Tyler Rogers...Greegers? Their combined 2021 stats were 17 W, 19 SV, 154 K, 2.68 ERA, and a 0.97 WHIP. The first SP off the boards, Gerrit Cole, finished with 16 W, 0 SV, 243 K, 3.23 ERA, and a 1.06 WHIP. 

In 2022's TGFBI, he ran it back using just five percent of his FAAB to create the "Helmes Deep" combo of Ryan Helsley and Clay Holmes. They combined for 16 W, 39 SV, 159 K, 1.90 ERA, and a 0.88 WHIP. The AL Cy Young Award winner Justin Verlander balled out with 18 W, 0 SV, 185 K, 1.75 ERA, and a 0.83 WHIP. He had "Helmes Deep" barely beat but still fell 39 saves short and cost a seventh-round draft pick versus a minimal FAAB investment.

Last season saw Mason Miller (ADP: ~250) and a waiver-add Cade Smith vault JB into the top three of our staff league. Here’s their line: 140 1/3 IP, 8 W, 29 SV, 207 Ks, 2.18 ERA, 0.89 WHIP. Tarik Skubal had 228 Ks with a 2.39 ERA and 0.92 WHIP in 52 more innings, getting 10 more wins in the process. But the superior ratios, saves, and over 50 IP to play around with for minimal draft investment are beautiful. Pocket the innings to preserve ratios or attack streaming.

Pretty simple, no? So we are not only making FrankenAces out of late-round picks/free-agent pickups, but at the same time, our offense is STACKED because while the rest of the league was wasting picks on their starting pitchers in the early rounds, we were grabbing the elite bats. That is the soul of the Bullpen Method and why it is so deadly. You are stacking your offensive categories and then winning/catching up on pitching categories on the back end without breaking a sweat.

Bullpen Method Drafting Strategy

As we've said numerous times already in this article, and will probably say a few more times, this is not a black-and-white strategy. You can't say, "I drafted Edwin Uceta because JB and Nick said relievers were better than starters, and he stunk, so I lost." That's why it is more of a state of mind, where names and roles don't matter. All you care about is numbers. If one guy isn't getting it done, move on, even if he is getting saves.

I have noticed over the years that the drafting strategy, specifically how you handle starting pitchers and closers, really doesn't matter with the Bullpen Method, which is what makes it so cool. You can get five true aces as your starting pitchers, you can get one ace and four mid-late round starters, or you can wait until Round 10 to get your first starter. Names don't matter. Those ~five arms are there to get you IP, W, and K to keep you afloat in those categories while your bullpen does the rest.

I ran a mock draft (using the fantasy baseball mock draft simulator) with my most common draft technique to show how little you need to focus on pitching early, especially starting pitchers.

I set up the mock with 12 teams, 5x5 Roto categories, and 27 roster spots: 1C, 1B, 2B, 3B, SS, CIF, MIF, OF x 5, UTIL, P x 9, Bench x 5. Picking from the 12th spot.

HITTERS (1 x SP, 1 x RP in first 10 Rounds) I randomized myself into the 12th spot. (Click to enlarge):

This draft technique is most common with the Bullpen Method. Look at that incredible hitting foundation through seven rounds! Snagging Spencer Schwellenbach at the 7/8 turn gives me ace upside, while Spencer Strider in Round 11 can be stashed away for a streamer slot or closer speculation.

But other than that, the first half of the draft is all about the bats. We’re looking to blow the league away offensively. Then, hit the pitching fast and furious in the second half. Schwellenbach, Strider, and Robbie Ray will only enhance my K/9 output. You can mix in starters as the board allows, of course.

The final bullpen was Jeff Hoffman, Trevor Megill, A.J. Puk, Jason Adam, Cade Smith, and Orion Kerkering. Let's see how the projections look:

This is the prototypical league Roto rankings layout for these teams. The offense is competing for the top spot in all categories because of the number of first-half picks on the stud hitters. Saves, ERA, and WHIP are GRAVY- despite only having two pitchers after Round 10.

That is the power of the 'pen. Some successful SP streaming throughout the season can vastly improve the K totals for some extra first-place padding, especially in daily-roster move leagues. Wins will take care of themselves, as all great RP tend to beat conservative win projections.

Okay, let's get down to business.

2025 Relief Pitcher Draft Targets

This season, once we cross into the second half of the draft and start filling my rotation and bullpen, these are some late-round relievers I'm targeting to build some FrankenAces (with consensus ADP):

A.J. Puk, ARI - 290 ADP

Puk is overlooked due to being overshadowed by Justin Martinez’s stretch run, the failed starter experiment, and being left-handed. His foray into Miami’s rotation displayed minimal command (12:17 K:BB in 13 ⅔ IP) and led to shoulder fatigue after a seven-run meltdown.

He missed a month and then returned as a reliever, though he still didn’t look like himself with just one strikeout in his first six appearances. Puk’s first 18 games yielded a 6.91 ERA (5.43 FIP) and a horrid 20:20 K:BB in 27 ⅓ IP. He still avoided barrels (4.3 percent), but he wasn’t right.

Well, his final 44 games brought an insane 0.82 ERA (1.28 FIP) with a 68:8 K:BB over 44 IP. Only Emmanuel Clase had a better ERA among 179 qualified RPs in that window. No one bested the 42.5 percent strikeout rate. Puk may be forced into the game wherever the high-leverage lefty is needed, leading to a smattering of wins and saves to go with elite form.

Griffin Jax, MIN - 295 ADP

Assuming you're a bullpen lover, considering your click on this article, there's little to explain about Jax. The 34.4 percent strikeout rate with a 2.03 ERA (2.15 SIERA) and 0.87 WHIP were epic. Securing 10 saves with Jhoan Duran out and scuffling certainly was endearing.

He did so well that Minnesota was kicking around the idea of Jax joining the rotation. Luckily for us, that is not happening. The 30-year-old has logged over 65 innings in all four of his big-league seasons thus far and can never be overlooked.

Jason Adam, SD - 320 ADP
Jeremiah Estrada, SD - 425 ADP

Adam grew into a stud RP after joining the Rays in 2022, his fourth team in five years, logging 24 saves with 10 wins, a 2.30 ERA, 0.88 WHIP, 2.98 SIERA, and a 30.4 percent strikeout rate over two and a half seasons with them.

Business is business, though, as the Rays shipped him to San Diego at last year’s deadline. He took to SoCal just fine, allowing a mere three runs over 26 ⅔ IP for them (1.01 ERA), even securing the win in three of his first five appearances.

But he didn’t get any saves as the Padres were more structured than Tampa, having also brought in Tanner Scott from Miami. But Scott is now a Dodger, and Robert Suarez is having a terrible spring.

For the spring Robert Suarez has a 19.64 era and 3.82 whip over 5 appearances. Time to push up Jason Adam and Jeremiah Estrada in your @TheReal_NFC Main Event rankings

— The Wardog (@IAmTheWardog) March 12, 2025

Consider Estrada if Adam’s price is too rich. The 26-year-old broke out with six wins, a save, 16 holds, and a beautiful 37.3 percent strikeout rate. He made headlines by setting an MLB record with 13 consecutive punchouts, but a midseason bout with the flu caused him to lose 15 pounds and stumble at times. Even so, a 2.95 ERA (2.39 SIERA) and 1.07 WHIP overall look incredible. Just know it could’ve been better!

Cade Smith, CLE - 330 ADP

Cleveland has proven willing to lean on its bullpen more than any other ballclub. We saw 11 relievers pitch in 74 or more games in 2024 and the Guardians supplied four of them. Smith always had big whiffs but historically logged double-digit walk rates in the minors, struggling to top a 50 percent first-strike rate.

But that jumped to 63.3 percent in the bigs as his walk rate nearly halved (5.9 percent), while the elite 35.6 percent K rate propelled savvy teams. He’s only 25 so durability concerns are low despite the high usage last year. He may not slide into the ninth if Clase’s volume catches up with him if Paul Sewald rebounds, but the trends cannot be overlooked.

Orion Kerkering, PHI - 335 ADP
Jose Alvarado, PHI - 600 ADP

Alvarado had a poor 2024 campaign that saw his strikeouts and grounders dwindle, but his early spring form is promising. He dropped some weight and is already hitting triple digits again, striking out seven of 13 batters faced over three scoreless frames.

Impressive day for Jose Alvarado. The Phillies LHP was up in velo across the board, especially his cutter (+2.8 mph) and 4-seamer (+2.5 mph)…topped out at 100.4!

— Sam Fosberg (@discussbaseball) March 9, 2025

Jeff Hoffman and Jordan Romano have swapped places, with the latter now bringing the most closing experience to Philly. Matt Strahm became the more reliable southpaw last year but rarely sees save opps. He’s had a tough opening to spring but the track record is undeniable. FrankenAce his 2023 and ‘24 years for 15 wins, 187 Ks, a 2.69 ERA, and 0.90 WHIP.

Kerkering has some ADP steam, but being the young right-hander behind Romano is a precarious position. But Romano is no bastion of health, taking this one-year deal to prove his health to the market for 2026, so don’t write off Kerkering.

Edwin Uceta, TB - 350 ADP
Mason Montgomery, TB - 500 ADP

Uceta is one of the most exciting non-closers after finding a home in Tampa, where 2024 saw him post the third-lowest ERA (min. 40 IP) behind Clase and Kirby Yates. An improved fastball-changeup combo carried the mail as he introduced a cutter and sweeper.

Montgomery is the latest left-handed marvel with a devastating fastball-slider combo who overwhelmed hitters in a 9 ⅔ IP window last year. He struck out 17 of 37 batters faced, giving up two runs on six hits and five walks.

He began the year as a starter at Triple-A but struggled to a 7.04 ERA with 19 HRs allowed and an 85:31 K:BB over 78 IP. The bullpen transition began on August 8 and led to a 20:5 K:BB across 9 ⅔ scoreless frames. So all told, Montgomery, the reliever, logged 37 strikeouts in 19 ⅓ IP of two-run ball.

Shoutout to Hunter Bigge for whenever he gets in the majors again, as well.

Camilo Doval, SF - 355 ADP

Doval fell off in 2024, losing the closer’s role thanks to a BB rate rising from 9.3 percent in ‘23 to 14.4 percent. He caught a lot of heat but one must point out his .187 xBA was actually the best mark of his career.

His 3.44 xERA was rosier beneath the 4.88 ERA, providing hope for the 27-year-old hurler. It’s Ryan Walker’s show, but a Doval bounceback is not a multi-step process, and we don't need the ninth for this to pay off.

Justin Slaten, BOS - 400 ADP

Slaten went 6-2 with a 2.93 ERA (2.76 SIERA) with a wicked 25.9 percent strikeout rate and a measly four percent walk rate as a rookie. He’s dealing with a sickness going around, which may be the same bug that caused Roman Anthony to lose 10 pounds.

It's poor timing given the spring struggles of Liam Hendriks and Aroldis Chapman. Still, talent wins in the long run and we won’t be thrown off course by a speed bump.

Robert Garcia, TEX - 405 ADP

Robert Garcia looks like the late-action lefty after a stellar 2024 campaign with a 2.38 FIP and 2.71 SIERA behind the 4.22 ERA. He held a tight 6.4 percent walk rate and isn’t a split specialist either, holding lefties to a .592 OPS and righties to a .624 OPS. Oh, and he finished the year with a pristine 18:0 K:BB over his final 17 contests- we'll take it!

Ryan Zeferjahn, LAA - 545 ADP

Zeferjahn, who finally got a chance on the Angels after several years in Boston’s system. At 26, the 6-foot-5 righty had a 2.12 ERA/0.76 WHIP and 18 strikeouts over 17 innings but didn’t get a hold and rode a .184 BABIP and 0 percent HR/FB.

Of course, he was also one of six pitchers with at least 35 batted-ball events and zero barrels surrendered. He might not be that good, but the Halos have little behind Kenley Jansen and Ben Joyce. Let's see what's cooking here.

Yimi Garcia, TOR - 699 ADP

This writer loves him some Jeff Hoffman but recognizes that there’s a notable element of risk for anyone with multiple hang-ups due to their physical. Garcia is our target behind him due to strong peripherals (under a 3.00 SIERA in two straight years) after tossing a career-best 32 percent strikeout rate last year.

The 34-year-old snagged five saves with a clean 3-0 record over 39 innings, holding a robust 3.46 ERA/0.90 WHIP. You point to the .202 BABIP with certainty that he’ll heavily regress, but a career mark of .261 isn’t terribly far. Plus, no one is projecting a replicated sub-1.00 WHIP.

That said, allow me to point out his pre-injury splits. He missed over a month after ulnar neuritis cropped up on June 16 (he was tagged for two runs) and never looked the same, eventually being shut down in August.

Before that game, Garcia had all three wins and the five saves with a 37:7 K:BB and 1.98 ERA/0.66 WHIP (2.37 SIERA) in 27 ⅓ IP. He’s thrown four scoreless spring frames with a 5:0 K:BB, so I’m back in until he gives me a reason to doubt.

Jose Leclerc, ATH - 700 ADP

Behind the star of last year’s piece, Miller, Leclerc looks to re-establish himself after an ugly 4.32 ERA led to his losing the closer job in Texas.

But the 3.48 FIP and 3.26 SIERA tell us there's still plenty in the tank. After early problems, he had a 62:14 K:BB in 45 ⅔ IP (3.55 ERA, 2.93 FIP). Those who are fearful of Miller's health should circle Leclerc on the board.

Abner Uribe, MIL - 710 ADP
Craig Yoho, MIL - 750 ADP

Yoho’s first full professional season was electrifying with a 0.94 ERA/0.94 WHIP (1.43 FIP) and 101 strikeouts with a grounder-heavy approach in 57 ⅔ IP. His changeup and sinker carry the mail, but his curveball and cutter give him options. All aboard with the Yoho Yo-Yo!

Craig Yoho is rightfully generating a lot of spring training buzz due to his insane changeup. Here’s how it compares to Devin Williams (2024)

Yoho: 78 MPH, 47 in vert, 18 in arm side, 45% whiff

Williams: 84 MPH, 42 in vert, 19 in arm side, 49% whiff

pic.twitter.com/Fzdkp4rEq2

— Tyler Koerth (@TylerKoerth) February 24, 2025

Uribe kicked off the 2024 season with three saves in the first week of play but wouldn’t get another. He was demoted after receiving a four-game suspension that remains unserved after suffering a season-ending knee injury (from playing Hacky Sack) in late May. But the 24-year-old was recently in the circle of trust and could swiftly rise again.

Will Vest, DET - 725 ADP

AJ Hinch’s Tigers sport a fluid bullpen with 5-6 arms who could reasonably sneak five or more saves. Jason Foley was often the guy last year, but the beats are skeptical he gets the same dedicated look. Tyler Holton, Beau Brieske, Tommy Kahnle, Will Vest, and even John Brebbia are viable options. Would you believe that Vest’s 3.43 SIERA paced the group in ‘24? The 35-year-old Kahnle and his knee-buckling changeup bring a good blend of Ks and ratios, but health has been an issue.

**Stay tuned, I'm still trying to perfect a Build-Your-Own FrankenAce Google Sheet. You'll be able to see their 2024 stats, their projected 2025 stats, and the ADP demanded from each with proper platform context. But I wanted to get this out of the door for a big draft weekend!

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