“We’re gonna utilize a six-man rotation.”

What are phrases that make you want to vomit, Alex? Six-man rotations are great for the organization, just not our organizations. If you’re reading this you’re probably not one of the 30 human beings with a pulse that are also employed as MLB general managers. But for fantasy baseball can potentially diminish value for players in a few different ways. Most teams across the league won’t be going with an extra starter. However, there are a couple teams that will and we do have some notes that we can take away. And I’m going to take a moment to give our very own Greg Jewett a massive THANK YOU because he provided me with some incredibly useful notes on six-man rotations. Greg’s been heavily involved with Fantasy Alarm’s offseason MLB coverage as well as draft guide content so definitely give him a follow (@gjewett9) on Twitter.

It goes without saying you’ll see fewer starts from pitchers in six-man rotations. Across the shorter 60-game season in 2020, starting pitching in deeper rotations lost two starts. In five-man rotations with 60 games, that’s 12 starts each. In six-man rotations, that comes out to ten starts each. Hurray for Math.

We don’t have a lot to look at covering the statistical differences between five-and-six-man rotations because the sample size was small a year ago for the Mariners and Angels. And keep in mind, comparing six-man rotations to five-man rotations is kind of like comparing apples and mushrooms. It’s not just the quantity of the rotation, but also the quality. An extra day of rest for each starter likely won’t help the Seattle Mariners’ ERA and WHIP compared to the stacked rotation of the San Diego Padres and they’re shiny new acquisitions this offseason. In this case you’ll definitely take more starts and (presumably) better numbers from the likes of Blake Snell , Yu Darvish , Joe Musgrove , and/or Mike Clevinger (pending his health).

The bigger issue we should take with six-man rotations is the lack of two starts you get out of your pitchers. Greg Jewett followed this closely with the Seattle Mariners last season. Across the ten-week fantasy baseball season last summer, Marco Gonzales was the only pitcher to see a two-start week and it came in the very last week of the season. A standard seven-day week for a baseball team will see roughly six games and an off day. That’s not to say some teams won’t have seven games in seven days or maybe a double-header mixed in as well. But six-man rotations are killers for two-start weeks, which make these pitchers less appealing when looking to stream a pitcher.

For the upcoming 2021 season, the Seattle Mariners will likely commit to the six-man rotation once again and it’s highly likely that Detroit Tigers do the same thing to protect their young arms. The Boston Red Sox are in the rumor mill of teams entertaining the idea of a six-man rotation, which is hilarious when you look at the garbage they deployed to the mound last season. Between Chris Sale , Eduardo Rodríguez , Nathan Eovaldi , Tanner Houck, Matt Andriese , Nick Pivetta , and Garrett Richards it’s quite possible we see the Red Sox experiment with six starters especially since Sale is coming off Tommy John surgery.

There are certain players who could benefit from a six-man rotation. A year ago, the Los Angeles Angels utilized this approach and, in theory, it should’ve been helpful for Shohei Ohtani . Ohtani came over from the Nippon Professional Baseball organization in Japan and, for the most part, that organization makes use of six-man rotations. So, having Ohtani as a designated sixth starter makes sense, and on the other days he can DH. Unfortunately, Ohtani’s pitching career has been derailed by injuries. He had to undergo Tommy John in his rookie season and he was limited to just two starts last season due to discomfort in his elbow. You’d think Yusei Kikuchi could’ve done better with a six-man rotation in the Mariners organization considering he also came over from the NPB, but he posted a 2-4 record last season with a 5.17 ERA although his 3.30 FIP and 3.78 xFIP suggest he ran into bad luck more often than not. Again, we don’t have enough of a sample size to really gauge whether fewer starts can actually help rate or ratio statistics, but it’s logical to assume there will be a drop in cumulative numbers such as total strikeouts, walks, earned runs, etc.

Looking at what we know for the 2021 season we have just a few teams looking at six-man rotations: Seattle, Detroit, and possibly Boston. Here’s a look at their rotation depth:




Marco Gonzales

Matthew Boyd

Chris Sale

Justus Sheffield

Tarik Skubal

Eduardo Rodríguez

Yusei Kikuchi

Casey Mize

Nathan Eovaldi

Justin Dunn

Michael Fulmer

Tanner Houck

Nick Margevicius

Spencer Turnbull

Nick Pivetta

Chris Flexen

Jose Ureña

Matt Andriese



Garrett Richards

I added Richards to Boston’s potential rotation, but there is the chance he ends up in the bullpen, which is how he finished last season with San Diego. But only a couple names should really stand out from each team.

For Seattle, Marco Gonzales is a worthy arm worth grabbing. He actually did seem to fare better in the six-man rotation. After boasting ERA’s of 4.00 and 3.99 in 2018 and 2019, in the shortened 2020 season he touted a 3.10 ERA and a 7-2 record across 11 starts. Not to mention, he sported a career-best 8.27 K/9 and 0.90 BB/9. The strikeout rate isn’t anything to write home about, but he has 36 wins over his last three seasons, and he’s proven to be pretty durable. He’s also the 44th pitcher off the board currently, which is a reasonable price tag although you won’t get many two-start weeks out of him.

Justus Sheffield fared okay in his first “full” season in the majors. He finished with a 4-3 record in ten starts with a 3.58 ERA. The strikeout numbers weren’t great (7.85 K/9) and the walk rate has room for improvement (3.25 BB/9). For a guy going outside the top 250, he’s likely only being drafted in deeper leagues, or he could be a waiver wire target if he takes drastic steps forward.

The Tigers are interesting. There are plenty of young arms in this rotation especially if you look at Tarik Skubal and Casey Mize . Combined they went 1-7 across 14 starts, but last season was truly just to let them get their feet wet in the big leagues. They both finished with ERA’s over 5.50 and both allowed over 2.20 HR/9. Make no mistake about it, the prospect pedigree is still there and Mize projects to be an ace. However, no Tigers pitcher is currently being drafted inside the top 80 starting pitchers. Do you really want to entertain the idea of double-digit losses from Matthew Boyd and his career 5.08 ERA? Sure, he has strikeout upside, but he’ll kill you everywhere else. If you feel inclined to take a late-round flyer on Skubal or Mize, be my guest. But for the most part you can shy away from this particular six-man rotation by drafting and locking more proven pitchers into your fantasy team.

The same almost goes for Boston. Chris Sale will be selected based on his name recognition and statistical output. But his ADP is currently taking a hit because he’s rehabbing from Tommy John and won’t be ready until maybe June or July. Eduardo Rodríguez missed last season after testing positive for COVID-19 and then he was diagnosed with myocarditis, inflammation of the heart muscle. But it does sound like E-Rod will be ready for the 2021 season after he began throwing again in November. Keep in mind he finished sixth in the AL Cy Young voting in 2019 and he had 32 wins combined in 2018 and 2019. His presence alone will raise the talent level of the Boston rotation, but for the most part it’s a group that doesn’t move the needle. Rodriguez is being drafted just inside the Top 70 pitchers.

The current ADP landscape has most of these pitchers downgraded, although there are other reasons aside from the lighter workload for these three teams. Add in prior health situations and performances in the shortened season and we have enough of a reason to downgrade a few arms without the acknowledgement of their six-man rotations. Following the 2021 season we’ll have a better read on the impact of six-man rotations. It would be a different story if we were seeing the Padres, Dodgers, Yankees, or Nationals make the transition. But until it becomes a more prevalent trend, don’t dwell on it too much.