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Watching the 2023 season play out and now following the 2023-24 offseason, one thing has become very clear: there is not enough pitching to go around these days. I mean, there's never been enough quality pitching to go around, but we're at a point now where teams are having a hard time finding enough pitchers to eat up 162 games worth of innings, never mind do it well.

Injury rates and the decline in pitcher usage -- only a select few pitchers are regularly allowed to go through the lineup a third time these days -- have led to the pitching shortage. Add in the fact that this offseason's free agent class was thin to begin with, and the pitching demand significantly outpaces the supply. There is a critical shortage of arms right now.

Teams have begun to resort to drastic measures to address their pitching needs. In recent years, several clubs have converted relievers into starters, and I don't mean the old school "you'll begin your career as a reliever, then we'll make you a starter" way of developing young pitchers. I mean taking established relievers, sometimes setup men and closers, and making them starters.

The Texas Rangers did this back in the day with C.J. Wilson. He saved 50 games from 2007-09, then moved into the rotation in 2010. He threw 842 innings with a 3.37 ERA the next four seasons. Wilson certainly was not the first reliever to successfully transition into the rotation, but it was a notable move at a time when the game was becoming more bullpen-centric.

In 2022, the Los Angeles Angels signed longtime Cincinnati Reds reliever Michael Lorenzen and put him in the rotation, and he gave them 18 league average starts around a shoulder issue. That same year, the Tampa Bay Rays took career reliever Jeffrey Springs and made him a starter. Springs made 25 starts following the in-season move and pitched to a 2.66 ERA.

The trend continued in 2023. The San Diego Padres signed former New York Mets reliever Seth Lugo, made him a starter, and he threw 146 1/3 innings with a 3.57 ERA. That was enough to earn him a three-year, $45 million free agent contract this winter. The New York Yankees put Michael King in the rotation down the stretch and he was so impressive he headlined the Juan Soto trade.

The Rays did it again this season too. Journeyman reliever Zack Littell came over in a May waiver claim and shifted into the rotation for good in July. He had a 3.41 ERA in 14 starts. Littell was needed as a starter in part because Springs, following his stellar debut as a starter in 2022, needed Tommy John surgery in April. Necessity tends to drive these reliever to starter conversions.

At least two pitchers will attempt the reliever-to-starter transition in 2024. The Atlanta Braves signed Reynaldo López to a three-year contract last month with the intention of stretching him out in spring training, and giving him a chance to start. The Miami Marlins will do the same with A.J. Puk, who opened the 2023 season as their closer. King will continue starting with the Padres as well.

Generally speaking, the pitchers who have successfully transitioned from reliever to starter have shared three common traits:

  • A history as a starter. These guys came up through the minors as starters. They've worked on a five-day schedule and have a between-starts routine already. So many relievers come up through the minors as relievers nowadays, and don't have that routine.
  • Three or more pitches. Even as a reliever, they threw three or more pitches regularly. Most bullpen arms these days lean on their two best pitches, or simply don't have a third pitch, which is why they're in the bullpen in the first place.
  • Good strike-throwing ability. Throwing strikes is crucial. You can survive and even thrive as a reliever with a high walk rate, but as a starter? It's very difficult to go through a lineup multiple times without good control.

King, Littell, Lugo, and Lorenzen all fit the mold. They were starters in the minors (and sometimes early in their MLB careers), they used wide arsenals as relievers, and they threw strikes. Experience matters too. There is something to be said for learning how to get outs at the MLB level as a reliever, then using what you've learned to get outs as a starter.

"Pitching all game, that's more fun than going out there for a couple batters and a couple outs," Lugo said after signing with the Kansas City Royals this offseason (via the Kansas City Star). "And that's what this game is about. It's about having fun. And if you can have fun and enjoy what you do, then your chance for success has greatly increased."

Given the dearth of available quality starters, both this offseason and in general, chances are more teams will give a reliever(s) a chance to start in the future. A lot of times a guy can string together a few good relief outings and suddenly the bullpen is his home even though he has to the ability to help his team as a starter. Those pitchers are getting a chance to start again.

With that in mind, here are three relievers who fit the profile -- history as a starter, three or more pitches, good control -- of the most successful reliever to starter conversions. 

LHP Tyler Holton, Detroit Tigers

Tyler Holton
DET • RP • #87
ERA2.11
WHIP.87
IP85.1
BB18
K74
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A spring training waiver claim from the Arizona Diamondbacks, Holton had a terrific rookie season out of Detroit's bullpen, and he was not simply a left-on-left matchup guy either. The 27-year-old got four or more outs in 33 of his 59 appearances and threw two full innings 19 times. Three times Holton went three innings or more. He was a multi-inning fireman, not a one-inning stopper.

Holton last started games regularly at Triple-A in 2021. He moved to the bullpen full-time while still in the minors in 2022 and that's when he put himself on the map. Holton has a history as a starter and he walked only 5.6% of the batters he faced this past season, well below the 8.6% league average. As for using three or more pitches, Holton falls into the "or more" category.


% thrownStatcast pitch value per 100 pitches

Four-seam fastball

28%

+2.59

Cutter

19%

+1.21

Sinker

12%

+5.64

Changeup

23%

+0.98

Slider

14%

+2.08

Curveball

4%

-0.90

Holton throws five pitches regularly -- the curveball is essentially a show-me pitch -- and all five are better than average according to Statcast's pitch values. Those tell us Holton's four-seamer was 2.59 runs better than the average four-seamer for every 100 thrown, so on and so forth. This isn't top of the line stuff but it is at least average stuff across the board, and that'll play as a starter.

Thanks to his deep arsenal, Holton was very good against both righties and lefties in 2023, so he doesn't have a worrisome platoon split. He really is two different pitchers. Against righties, Holton throws his four-seamer, changeup, and cutter. Against lefties, he uses the four-seamer, sinker, and slider. He has specific weapons for specific hitters, and can attack just about any weakness.

Holton paired his excellent walk rate with a league-average strikeout rate (22.8%) and an above-average ground ball rate (45.6%). He is also excellent at suppressing hard contact. His 86.1 mph average exit velocity and 32.5% hard-hit rate (i.e. percent of batted balls over 95 mph) were both much better than the MLB averages (89.0 mph and 39.2%, respectively).

This risk here is Holton already works with below-average velocity as a reliever. His four-seamer and sinker both sit around 91.5 mph, and Holton did not throw a pitch over 94.0 mph in 2023. Velocity isn't everything, but it's not nothing either. A move back into the rotation could mean a fastball in the 89-91 mph range, shrinking Holton's margin of error.

Despite that, giving Holton a chance to start seems worthwhile for a Tigers team that is not quite out of the rebuild yet, and has a lot of innings to fill next season. He's experienced success at the MLB level now, he has a deep arsenal and pitchability, and he's able to limit hard contact. Holton's great as a reliever. It's worth finding out whether he can be effective as a starter too.

LHP Tanner Banks, Chicago White Sox

Tanner Banks
CHW • RP • #57
ERA4.43
WHIP1.23
IP61
BB16
K51
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It's sort of wild that, in the middle of a 101-loss season in which everything went off the rails, the White Sox only gave Banks three starts in late June while holding him to a 65ish pitch limit. Banks is not a young kid -- he's already 32 -- but Chicago ran Jesse Scholtens and Touki Toussaint and Jose Ureña out there for a combined 34 starts in 2023. Banks could only get three?

Anyway, Banks is a four-pitch southpaw (four-seamer, slider, curveball, changeup) with a homer problem against righties (2.1 HR/9 vs. RHB in 2023), but he does throw strikes and, on paper, has enough weapons to turn over a lineup multiple times. Chances are he would only be a five-inning, two-times-through-the-order guy at best, but that's fine. Teams need those guys too.

Banks threw at least two innings in 16 of his 29 relief appearances this past season, and four times he went at least three innings. He works with average fastball velocity and, at age 32, maybe the juice just isn't worth the squeeze. The White Sox appear to be entering another rebuilding phase, so they could prioritize young players and let Banks soak up miscellaneous innings as needed.

I think that's the wrong way of looking at it. Chicago is in position to experiment with their pitching staff, including trying Banks (or another reliever) as a starter. If it doesn't work, so be it. In that case, the White Sox are right back where they started. If it does work though, Banks suddenly becomes a more desirable trade chip who could help advance the rebuild that way. 

They don't check IDs on the mound. If you can get outs, teams don't care if you're 22 or 32 or 42. Lugo pitched just about the entire 2023 season at age 33, then he was an in-demand pitcher in free agency. Banks may be 32, but he also has a league minimum salary as a pre-arbitration player. Even as a No. 5 starter, he'd have trade value. It's worth seeing whether he can start.

The ChiSox are considered behind the times with player and particularly pitcher development. There's a reason teams are lining up to get Dylan Cease. He's very good as it is, but there's also a belief that a team with a more modern pitching program could get Cease to another level, one where he maintains his 2022 AL Cy Young runner-up performance over multiple seasons.

It's possible the White Sox are not equipped to get the most out of Banks and his best chance to have success as a starter would come with another team. That doesn't mean the White Sox should give him away or not try though. When you're a rebuilding team short on decent pitching, seeing whether the four-pitch strike-throwing lefty has more to give is worth a try.

RHP Trevor Stephan, Cleveland Guardians

Trevor Stephan
CLE • RP • #37
ERA4.06
WHIP1.3
IP68.2
BB26
K75
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I did not mean to pick three AL Central pitchers. It just sort of happened that way. With all due respect to Holton's 2023, Stephan is the most accomplished pitcher in this post. The recently turned 28-year-old has spent the last three seasons as a trusted setup man, one with bat-missing ability and improving control. And three pitches too. That helps.

The Guardians selected Stephen from the Yankees in 2020 Rule 5 Draft. He'd started in the minors, spent the 2020 canceled minor league season at home, then Cleveland grabbed him based on their pre-2020 reports. The Guardians are one of the best pitcher development teams in the game. Maybe the best. They found Stephan at a time when things were bizarre. Credit to them.

Thanks to a power three-pitch mix -- mid-to-upper 90s fastball plus a mid-80s splitter and mid-80s slider used in near equal parts -- Stephen has missed a lot of bats and also avoided a significant platoon split. He's effective against righties and lefties, he doesn't allow too much hard contact, and he certainly now knows how to get outs at the big league level.

Unlike Banks and Holton, Stephan has primarily been a one-inning reliever. Only 17 times in 180 career games has he thrown two full innings, and 15 of the 17 came in 2021, when he was a rookie and the proverbial last guy in the bullpen. Stephen was asked to get more than three outs only four times this past season, so it's been a while since he's thrown longer outings.

Cleveland signed Stephan to a four-year, $10 million contract with two club options in March 2023 and the deal includes several bonuses tied to Reliever of the Year voting. That strongly suggests they're not planning to try Stephan in the rotation, and hey, the Guardians are really good with pitchers. They know what they're doing in that department, so who am I to doubt them?

Still, he fits the profile as a pitcher who has started in the past and throws strikes with at least three pitches. Cleveland had success converting Cal Quantrill from a reliever into a starter midway through the 2021 season, so they certainly know how to handle such a transition. The rotation may not be a significant need right now, but you can never have enough starters, right?


It feels like the sport is reaching a collective tipping point with pitching. The game has become so bullpen-heavy in recent years that teams are running out of starters. The war of pitching attrition has never been greater. As a result, a few teams resorted to turning relievers into starters the last few years, and others will follow suit. If one team does it and it works, others will undoubtedly try it.

Banks, Holton, and Stephan are only three examples of relievers who, at least on paper, appear to have a chance to be successful starters. And that doesn't mean pitching at an ace level either. There's a lot of value in throwing 130 league-average innings. There are good starting pitchers hiding in plain sight out there in the bullpen. It's on the clubs to start finding them.