Could the Minnesota Twins Embrace a Six-Man Rotation in 2025?

I want to say "no", mainly because of the simple math of "13-6=7" for the work to be spread among the bullpen arms. 

But if certain assumptions are true (or can be made to be true), maybe it works:

• If 28 starts instead of 32 starts results in a par of 7 innings per start instead of the current 6, due to there being more time to recover between starts, then you are back to your best starters pitching a good proportion of the season's innings.
• If your 40-man roster carries enough bullpen arms with minor-league options remaining, then you can identify your core of 5 or so relievers who you hope will stay with the big club all year, and shuttle the two remaining spots up and down to St Paul.
• Those shuttle relievers need to be worked like rented mules during their stints with the big club, and go to St. Paul mainly for rest and staying in tune, meaning that there is additional workload at St Paul for the castoff veterans that our front office is fond of signing.

If instead the 40-man roster is littered with guys who have to be DFAed every time you send them to St Paul, you end up losing the good ones on waivers and wind up with a ragtag assortment of arms no one else wants.  Meanwhile if one or more of your 6 starters is like SWR was last season, delivering 5 good(ish) innings per start, you begin to risk overworking your bullpen even if you use the shuttle system, because roster rules require you to leave a pitcher down there for many days at a time (they keep changing this and I can't remember the current rule).

If the plan is to hook the starter at the first sign of trouble and 5 innings is satisfactory per start, then some other simple math takes over.  162*9=1458 innings to cover, and 5*28=140 innings per starter, times 6 equals 840 innings, leaving 618 innings to be covered by 7 spots in the bullpen.  Last year the Twins bullpen pitched 588 innings, and many of us felt at the time that this was straining things with 8 arms.  The manager and pitching coach would have to change their strategy with 6 starters, in the opposite direction they have trended - of trusting perhaps their top 3 veteran starters, but not the young'uns.

So I still want to say "no".  😀

14 minutes ago, dxpavelka said:

Totally wrong approach.  Not even a 5 man rotation but a 5 day rotation.  # 1 guy starts every 5 days regardless.  The lower the guy is in the rotation the more likely he gets skipped because of off days or rain outs.  I'm shocked that the analytics crowd hasn't picked up on this.  Why would your run your # 4 or 5 guy out there when your # 1 or 2 last pitched 5 days ago and is ready to go and gives you a much better chance to win. 

A good question, and I think it would be very interesting to ask it of someone like Pablo Lopez, someone I believe to be as much a student of the game as a prime athlete and skilled pitcher.  I am guessing that the answer we might get is that, even if he doesn't like to admit it, he appreciates the occasional extra day between starts because it's a strain to pitch every 5 days without a break, and his performance will be better.  But I'm not the athlete, just the asker, and it's only a guess on my part.

23 minutes ago, ashbury said:

But I'm not the athlete, just the asker, and it's only a guess on my part.

Following up, because I had an idea after posting....

Lopez is someone to look at, empirically, and b-r.com has the pieces thanks to its game log.  In 2024 he had 10 starts on 4 days of rest (i.e. the every-five-day pattern being suggested), out of his 32 starts.  If I added correctly, he pitched 61.0 innings in those games, and gave up 20 earned runs.  That's an ERA, on "short rest" by today's standards, of 2.90 if I haven't goofed up the math.

Compared to his season ERA of 4.08, that's a pretty strong difference.  He had several stinkers among his starts, and only one of those was on 4 days' rest.

There's a heavy chicken-and-egg factor here, or call it a hidden statistical bias, since the manager and pitching coach get to choose each game's starter, and perhaps they put Pablo in the game on 4 days' rest only when they felt that he was going well.  It's not the random process that good statistical analysis relies on, at all.  I'd also want to assort his starts by "how did he do in the start following the game he pitched on short rest," in case there might be a pattern there. Need to look at Pablo's 2023, etc.  Life is short, or at least my attention span is.

Still, it's a pretty intriguing argument in favor of the 5-day plan for your best pitcher if his first name is Pablo.  I'd want to look at similar analysis for Ober and Ryan, but unless they have a similar pattern, I'd advocate for "let Pablo be Pablo, and the others can go pound sand until they show they deserve the preferential treatment."  😀

4 minutes ago, Linus said:

Or the myriad sayings involving manure……

Yeah, no kidding, Sherlock.  😀

9 minutes ago, Linus said:

Or the myriad sayings involving manure……

As a dairy farm kid, I can relate. 

15 minutes ago, ashbury said:

Following up, because I had an idea after posting....

Lopez is someone to look at, empirically, and b-r.com has the pieces thanks to its game log.  In 2024 he had 10 starts on 4 days of rest (i.e. the every-five-day pattern being suggested), out of his 32 starts.  If I added correctly, he pitched 61.0 innings in those games, and gave up 20 earned runs.  That's an ERA, on "short rest" by today's standards, of 2.90 if I haven't goofed up the math.

Compared to his season ERA of 4.08, that's a pretty strong difference.  He had several stinkers among his starts, and only one of those was on 4 days' rest.

There's a heavy chicken-and-egg factor here, or call it a hidden statistical bias, since the manager and pitching coach get to choose each game's starter, and perhaps they put Pablo in the game on 4 days' rest only when they felt that he was going well.  It's not the random process that good statistical analysis relies on, at all.  I'd also want to assort his starts by "how did he do in the start following the game he pitched on short rest," in case there might be a pattern there. Need to look at Pablo's 2023, etc.  Life is short, or at least my attention span is.

Still, it's a pretty intriguing argument in favor of the 5-day plan for your best pitcher if his first name is Pablo.  I'd want to look at similar analysis for Ober and Ryan, but unless they have a similar pattern, I'd advocate for "let Pablo be Pablo, and the others can go pound sand until they show they deserve the preferential treatment."  😀

I've wondered the same. What this doesn't take into account, however, is the cumulative fatigue of pitching on four days' rest after every start. It also has the effect of non-Pablos sometimes going on four days, sometimes six, and sometimes even seven, depending on where off days follow.

11 minutes ago, IndianaTwin said:

I've wondered the same. What this doesn't take into account, however, is the cumulative fatigue of pitching on four days' rest after every start. It also has the effect of non-Pablos sometimes going on four days, sometimes six, and sometimes even seven, depending on where off days follow.

Well said, and my little bit of arithmetic only scratches the surface of the work needed.

Still if you could obtain an ERA of 2.90, instead of the 4.63 that Pablo had in his other games, you'd move mountains to get that if it was sustainable, and the other pitchers would just have to cope.

A modified rule could be "Pablo pitches 5 days from today, unless today's start was a stinker and we'll give him an extra day."

But it's not as simple as the "if" I just stated.  And yes, the other pitchers would complain about not being given a fair shake, if their numbers didn't pan out and they wanted to blame the irregularity between starts.  Maximizing Pablo's performance might not quite match maximizing the entire staff's.

A significant factor in the number of starts on five days having increased is the additional off days that were added to the schedule a few years ago. Each off day typically creates five starts that are happening on five days (or sometimes six). When they switched to starting the season on Thursday, they added four off days, which translates to 20 games being started with an extra day.   

If the Twins were to follow a strict five-pitcher rotation for the entire season, they would have only 60 starts on four days rest, 88 on five days and 4 on six days. Scheduled off days are a bigger factor in the number of extra days than is the idea of "giving someone an extra day" with a six-man rotation or a spot start by someone. 

That totals 152. There would also be five starts on nine days rest following the All-Star Game and it doesn't count the first five days of the season, though those are often either done on at least five days rest as well or are after a final spring training outing that didn't include a huge number of pitches. .

For what it's worth, I did the same math with a strict four-pitcher rotation. There would be 79 starts on three days rest, 73 on four days and 5 on five days, along with the four starts that would now be on seven days rest at the All-Star Break and the four starts at the beginning of the year.

There might be a benefit to using the “best” pitcher more often, juggling the other guys into a more irregular schedule most likely negates the benefit of getting the #1 more starts and innings. It only takes one guy who is affected to negate the benefit. 

I actually think that with the Twins apparent depth in the bullpen, they’re best served with eight relievers. 

4 hours ago, ashbury said:

I want to say "no", mainly because of the simple math of "13-6=7" for the work to be spread among the bullpen arms. 

But if certain assumptions are true (or can be made to be true), maybe it works:

• If 28 starts instead of 32 starts results in a par of 7 innings per start instead of the current 6, due to there being more time to recover between starts, then you are back to your best starters pitching a good proportion of the season's innings.
• If your 40-man roster carries enough bullpen arms with minor-league options remaining, then you can identify your core of 5 or so relievers who you hope will stay with the big club all year, and shuttle the two remaining spots up and down to St Paul.
• Those shuttle relievers need to be worked like rented mules during their stints with the big club, and go to St. Paul mainly for rest and staying in tune, meaning that there is additional workload at St Paul for the castoff veterans that our front office is fond of signing.

If instead the 40-man roster is littered with guys who have to be DFAed every time you send them to St Paul, you end up losing the good ones on waivers and wind up with a ragtag assortment of arms no one else wants.  Meanwhile if one or more of your 6 starters is like SWR was last season, delivering 5 good(ish) innings per start, you begin to risk overworking your bullpen even if you use the shuttle system, because roster rules require you to leave a pitcher down there for many days at a time (they keep changing this and I can't remember the current rule).

If the plan is to hook the starter at the first sign of trouble and 5 innings is satisfactory per start, then some other simple math takes over.  162*9=1458 innings to cover, and 5*28=140 innings per starter, times 6 equals 840 innings, leaving 618 innings to be covered by 7 spots in the bullpen.  Last year the Twins bullpen pitched 588 innings, and many of us felt at the time that this was straining things with 8 arms.  The manager and pitching coach would have to change their strategy with 6 starters, in the opposite direction they have trended - of trusting perhaps their top 3 veteran starters, but not the young'uns.

So I still want to say "no".  😀

The only way I could see working well is if you have at least 3 good relievers that can go 2 innings every other day, and may occasionally need them a 2nd consecutive day. I don't see that with the Twins roster.

3 hours ago, ashbury said:

Well said, and my little bit of arithmetic only scratches the surface of the work needed.

Still if you could obtain an ERA of 2.90, instead of the 4.63 that Pablo had in his other games, you'd move mountains to get that if it was sustainable, and the other pitchers would just have to cope.

A modified rule could be "Pablo pitches 5 days from today, unless today's start was a stinker and we'll give him an extra day."

But it's not as simple as the "if" I just stated.  And yes, the other pitchers would complain about not being given a fair shake, if their numbers didn't pan out and they wanted to blame the irregularity between starts.  Maximizing Pablo's performance might not quite match maximizing the entire staff's.

I enjoy projecting starters, so I decided to play with this, knowing that the first injury makes this all moot.

For reference, a pure five-man rotation would result in 32 starts for each, with a 33rd start for the top two, who I'll call Lopez and Ober. 

In comparison, I went through the schedule with the following plan:

1. Lopez starts every fifth day, unless that lands on an off day, in which case he opens the next series. He would start 36 games.
2. Ober also starts every fifth day, unless that lands on an off day or a Lopez start, in which case he takes the next available game. He would start 35 games. 
3. Ryan also starts every fifth day, unless that lands on an off, Lopez or Ober start, in which case he takes the next available day. He would start 34.
4. That leaves 57 games. If you want to maximize the remaining starts with No. 4 (I used SWR), he would get 32 starts and leave 25 for No. 5 (Paddack). They could easily be adjusted to balance the two a bit more evenly, however. 

So in summary, maximizing the starts of Lopez, Ober and Ryan would result in taking seven starts from SWR/Paddack and moving them to Lopez (3), Ober (2) and Ryan (2). 

Summarizing further...

• Lopez would have his rested first start, following by 29 starts on four days and six on five days. Lopez starts the last game before the All-Star Break and the first game after, so that doesn't affect his rest.
• Ober would have his rested first start, seven days off around the ASB, seven starts on five days and the remaining 26 starts on four days.
• Ryan would have his rested first start, a 10 day rest at the ASB, a start on six days, seven starts on five days and the remaining 24 starts on four days.
• If SWR's starts were maximized at 32, his first will be rested, with a 10 day rest at the ASB, seven starts on six days, six starts on five days and 18 starts on four days. The reason he has a bunch of six day rests is because when there is an off day that would already bump him back to five days, he is often bumped an additional day by starting the series with Lopez, Ober or Ryan. 
• Paddack would be throwing on a very inconsistent pattern. He'd only have six starts on four days, two on five days, seven on six days, two on seven days, four on eight days, two on nine days and one each on 10 and 11 days. What it looks like is 7-6-4-11-4-8-6-7-8-4-5-6-4-8-6-9-6-6-6-4-5-9-4-8-10 days off. I suppose there would be a few times when they could use him out of the bullpen a time or so in the breaks that are maybe eight days or longer, but the team has been reluctant to do that.

As noted, it would be possible to balance SWR and Paddack's starts to 29 and 28. If I just alternated SWR and Paddack in the remaining starts, they each have nine starts on four days, but only five on five days. Then they have 10 and 8 starts on six days respectively and a combined three starts on seven days, three on eight, two on nine and one on 10. 

So, while maximizing starts for Lopez, Ober and Ryan gets them seven additional starts, the tradeoff is that it uses SWR and Paddack on a much more inconsistent manner. When you combine the reality that this approach would rarely give Lopez/Ober/Ryan an extra day with the inconsistent usage it provides for SWR and Paddack, I think the better option is just to stay with the five-man rotation.