clock menu more-arrow no yes mobile

Filed under:

Rethinking the Rotation for a Compressed Season

We make some assumptions about the 2020 season and then imagine four-, five-, and six-starter rotations.

League Championship Series - St Louis Cardinals v Washington Nationals - Game Three Photo by Will Newton/Getty Images


In a compressed, 100-game season with doubleheaders, what rotation format do you prefer?

This poll is closed

  • 19%
    5-Starter Rotation with Bullpen Starts
    (100 votes)
  • 57%
    6-Starter Rotation
    (301 votes)
  • 23%
    4-Starter Rotation with Piggybacks
    (122 votes)
523 votes total Vote Now

With the Korea Baseball Organization beginning play, I’ve been thinking this week about Kwang-Yhun Kim. Kim looked excellent in spring training. Mikolas’ injury made him a virtual lock for the rotation out of spring and his performance was making me wonder who he might displace when Mikolas returned. A normal five-man rotation, including a healthy Mikolas, could have left the Cardinals without an opporutnity to find out what KK could do as a starter.

But who said a rotation needs 5 starters anyway? Why not 4? Or 6?

The uncertainty surrounding the 2020 season and the likely changes that will come if baseball has a season this year almost demand that clubs rethink the way their rotation operates.

To help guide today’s conversation, I want to lay out five assumptions about how the season will play out. These assumptions might prove true. Or they might be way off. Regardless, for today, we’ll assume:

  1. MLB divides into three divisions – East, Central, and West – with no games outside of regions.
  2. Teams play a 100 game season.
  3. One double-header every week on the same day of the week
  4. Active rosters will be expanded to more than 26 but less than 40.
  5. Limited or no off-days.

These assumptions are based loosely on information that has been leaked so far and they make some kind of sense. If the season was to begin in early July, MLB would have all of May to evaluate the current situation with the virus and all of June to prepare to play, likely without fans.

From July 4th to September 26 there are 12 weeks. 12 weeks x 7 games per week + 12 doubleheaders (1 extra game per week) = 96. Stretch until October 3 and baseball would be able to work in one day off for clubs per month (or skip a doubleheader) and play exactly 100 games.

The math works. With those assumptions in place, what’s the most effective way to make a rotation work? I put this out on Twitter and the Cardinals collective talked through three ways that the Cardinals could approach a rotation for the season under the above assumptions.

Option 1: 5-Starter Rotation with Bullpen Starts

This approach is the most obvious but not as straight forward as it might appear. Every rumored plan for the season has included extensive doubleheaders. This presents a unique challenge for a traditional 5-man rotation. In order to maintain regular rest, someone outside of the rotation would have to start the extra game. In this scenario, the Cardinals use their expanded bullpen to cover doubleheaders.

There are pros and cons to using a traditional rotation structure. First, from the time starters enter professional ball they are immersed in a training and preparation regimen that assumes 4 days of rest between starts. With everything about this season changing from the norm, providing pitchers with some sense of the familiar might be worthwhile.

However, dedicating 12% of a team’s total games to the bullpen seems less than ideal. Expanded rosters would ease the stress of overworking the pen, but it would also cause the team to dig deeper into the bullpen’s depth charts. That’s not a great way to win games in a tightly-contested “region”. A 5-man rotation offers stability and simplicity, but little upside.

Option 2: 6-Starter Rotation with Regular Rest

If MLB chooses to include a doubleheader every week, I believe that they will have a “doubleheader day” – one day of the week where every team plays a doubleheader. This would help balance scheduling and competitiveness throughout the league.

A regularly scheduled doubleheader day would allow six starters to maintain the normal four-days rest while working in an extra day of rest for two starters every week. It would also provide teams with the opportunity to push the weakest starters in a rotation back while bumping up the strongest on normal rest. Flaherty and Martinez, for example, could remain on 4 days rest to maximize their start percentage, while Wainwright and Hudson could be bumped back to limit their exposure. The following table presents these as two different possibilities:

6-Man Unmodified Rotation

- Monday Tuesday Wednesday Thursday Friday Saturday Sunday
- Monday Tuesday Wednesday Thursday Friday Saturday Sunday
Week 1 Flaherty Martinez Mikolas Hudson KK Wainwright Martinez (4)
Doubleheader Flaherty (4)
Week 2 Mikolas (4) Hudson (4) KK (4) Wainwright (4) Flaherty (5) Martinez (5) Hudson (4)
Doubleheader Mikolas (4)

6-Man Modified Rotation

Monday Tuesday Wednesday Thursday Friday Saturday Sunday
Monday Tuesday Wednesday Thursday Friday Saturday Sunday
Flaherty Martinez Mikolas Hudson KK Wainwright Martinez (4)
Flaherty (4)
Mikolas (4) Hudson (4) KK (4) Flaherty (4) Wainwright (5) Martinez (5) Hudson (4)
Mikolas (4)

This plan would be challenging for teams who cannot project six above replacement level starters but it would allow the Cardinals to make good use of KK, Wainwright, or even Ponce. (I would personally love to see KK in this role.)

The downside to a 6-man rotation is that it requires six effective starters. If (when) the Cardinals experience injuries or if a rotation member scuffles, the club would have to find production from down roster sources, like Austin Gomber or even Jake Woodford.

Option 3: 4-Starter Rotation with Piggybacks

In 2019, it took the Cardinals 162 games to build a seven-game margin over the third-place Cubs. Cut that back to 100 games and that margin becomes four. Sure, the playoffs will likely be expanded, but in the pursuit of a division (or region?) crown, every game takes on even greater significance. Shouldn’t that mean that a club needs to play its best players as much as possible to maximize their performance?

In a 162 game season, a healthy starter will throw between 30-32 games and 175-200 innings – roughly 6 innings per start. In a 6-man unmodified rotation, that number gets cut to 16-17 starts and just 100 innings over 100 games. In a 5-man rotation with 12 bullpen starts, that number barely changes – 16-17 starts and 106 innings.

What about a 4-man rotation? This plan would take the best four starters – Flaherty, Martinez, Mikolas, and Hudson, for example – and throw them every 4 days on short rest. These starters would not be asked to assume a full workload. Instead, they would be limited by a pitch or inning count. I’m suggesting 4-5 innings or 75-90 pitches, depending on how each starter looks and feels each day. They would be supported by piggyback starters who throw 2-3 innings per outing on 2 days rest – KK, AW, Ponce. The doubleheader game would be started by one of the piggyback starters on just one day of rest or by others in the bullpen, depending on workload.

4-Man Rotation

Monday Tuesday Wednesday Thursday Friday Saturday Sunday
Monday Tuesday Wednesday Thursday Friday Saturday Sunday
Flaherty Martinez Mikolas Hudson Flaherty (3) Martinez (3) Mikolas (3)
KK Wainwright Ponce KK Wainwright Ponce Wainwright

Under this plan, Flaherty would receive 22 starts (100 games minus 12 doubleheaders divided by 4). That still results in just 90-110 innings, but Flaherty would impact 5-6 additional games. Those games matter. It would also expand the influence of starter-caliber arms while giving their stuff the ability to “play up” over shorter bullpen stints. KK, for example, could earn 77-100 innings in a piggyback role. The result is between 6-8 innings every game devoted to two of the best 7-9 arms on the club. The rest of the innings allow the bullpen to be used as they normally would.

There’s a poll at the top of this article. Vote! Let me know what you think democratically and explain your reasoning in the comments.

My take? The more I think about it, the more I like the idea of Jack Flaherty pitching every four days over a shortened season. I also love the idea of Ponce and KK receiving 2-3 innings every few days in place of arms like Tyler Webb and Junior Fernandez. However, I don’t think there is any chance the Cardinals will consider this option. The club is not one to take risks and there are probably elevated injury risks to pitchers by repeatedly throwing on 3-days rest.

The 6-man rotation is also appealing because it provides the opportunity for the club to maximize KK’s presence and it does not inhibit the Cardinals from rolling Flaherty, Martinez, and/or Mikolas on regular rest. It’s less aggressive than I believe a compressed schedule demands, but it eliminates bullpen starts.

What do I think the Cardinals will do? If the season plays out according to the assumptions I outline above, I suspect them to stick with 5 starters and make things work for the doubleheaders using available arms. This is the least attractive option to me as well as the least impactful, but it is the most familiar.