The Costs and Benefits of Six-Man Rotations
Planning a starting rotation for 2021 carries innumerable pitfalls. Nearly every pitcher in the league saw a reduced workload last year, and they did it in strange circumstances to boot. It’s not merely that the short season set everyone’s innings back — though that’s a huge component. A large number of cancelations and postponements also meant more doubleheaders and more cobbled-together games, another way to throw pitchers off their rhythm.
Put it all together, and protecting arms sounds like an appealing plan for 2021. The Mariners announced that they’ll use a six-man rotation next year, a continuation of the plan they leaned on for all of 2020. The Red Sox are talking workload management. Since initially publishing this piece, Jeff Zimmerman pointed out that the Tigers will use a six-man rotation as well. Is an embiggened rotation the solution to this universal problem? Let’s do the math.
It depends, first of all, on what you give up. The innings tradeoff of a six-man rotation is straightforward. Giving your pitchers an extra day off limits their workloads, naturally enough. The math on that is straightforward if you assume it doesn’t affect their in-game workload. Take a pitcher who averages six innings per start. In a five-man rotation, that’s 192 innings of work. Adding a sixth pitcher to the rotation cuts that down to 162 innings.
How much do those 30 innings of work matter when it comes to health? I’ll level with you — I’m not sure. We simply don’t have the data to say with any amount of certainty, because the number of comparable situations is so small. Pitchers have light workloads all the time, but in most cases it’s due to age or injury. Looking at what a 21-year-old pitcher did in first building up stamina probably can’t tell us much about how many innings Jake Odorizzi, to pick a random example, should throw in 2021. Likewise, a pitcher’s workload in his first year back from Tommy John surgery can’t tell us how many innings Trevor Bauer can be effective for.
We do have a few points that we could look at for a natural experiment. The ‘94 strike depressed every pitcher’s workload, injured or not. The problem, here, is that due to the length of the pre-strike season, no healthy pitchers added innings in the way we expect to see this year. Heck, Greg Maddux threw 202 innings in 1994. He threw 209.2 the next year. Lance Lynn led baseball with 84 innings pitched last year, and we project him for 191 in 2021. The increase in workload isn’t comparable.
The same problem exists for the 1981 season. To make matters worse, pitcher workloads barely resembled today. In 1982, 50 pitchers threw 200 or more innings. In 2019, only 15 hit that threshold. Speculating on what will happen to modern pitchers based on what happened to Charlie Hough in the 80s hardly seems like a productive approach.
Fine, then: we won’t assume any benefit, at least from a performance perspective, from adding an extra pitcher to the mix. That doesn’t mean there’s no benefit at all, however. An extra day of rest gives pitchers more time to recover between starts. Assuming no benefit from that rest doesn’t make much sense to me.
To approximate this effect, I looked at the number of days of rest between each start made in baseball this year. I threw out starts made on three days’ rest (there were only 14) and starts made on seven or more days of rest — those aren’t rotation- or schedule-based. That left me with 1,291 starts to look at.
You might think that the right thing to do is simply look at league ERA on four, five, and six days’ rest. You’d be wrong, though, due to population effects. Pitching on standard rest — or getting an extra day to recover — isn’t a decision that teams make at random. They have motives, and those motives depend on the identity of the pitcher. Getting an ace an extra turn makes sense. Using a bad pitcher as infrequently as possible makes sense. If you ignore this distributional effect, you’re liable to end up with a confusing answer.
Instead, I focused on how each pitcher fared relative to their seasonal line. I focused on xFIP, since we’re looking at noisy individual game lines, and compared starts on each relevant amount of rest to a pitcher’s overall seasonal line. In other words, if a pitcher had a 4.50 xFIP overall, a 4.60 xFIP on regular rest, and a 4.40 xFIP on five days’ rest, we’d say that four days’ rest increases his xFIP by 0.1 while five days’ rest decreases it by 0.1, an overall difference of 0.2 runs.
The numbers don’t need to be exactly symmetrical like that example, of course. Pitchers don’t make an equal number of starts with each type of rest, and they also don’t pitch an equal number of innings per start in each case. The overall point, however, is that extra days of rest seem to have a small but beneficial effect on pitchers’ results. For each extra day of rest, their xFIP improves, relative to their seasonal average, by roughly 0.06.
I won’t claim that this effect is obvious and incontrovertible. It’s tiny, below the threshold of statistical significance. Break it down into strikeouts and walks, and it’s even smaller; an extra day of rest is associated with a 0.3 percentage point increase in strikeout rate but also a 0.15 percentage point increase in walk rate.
In other words, the extra day of rest doesn’t appear to be worth that much. If you take my math at face value and assume that all previous starts were on regular rest — a poor and lazy assumption that I’m absolutely going to make for the sake of time — that works out to something like 6.5 runs over the entire season. Though I’m tired of saying it, I still will — I have very little confidence in this number. As a ballpark guess, however — and pun very much intended, I have a reputation to uphold — I think it gets the job done.
Okay, so teams can get an indeterminate injury benefit and also maybe save 6.5 runs by going to a six-man rotation. Let’s talk cost. The cost is clear: your top five starters all throw roughly 30 fewer innings, and those innings get replaced by your sixth-best starter. Sorry, Max Scherzer, but it’s Austin Voth’s turn to shine, and so on.
The cost of this downgrade varies by team. It depends on two things: the average quality of your existing rotation and the quality of your sixth starter. To approximate this cost, I took Depth Charts projections for every team in baseball and then calculated the existing rotation’s average projected ERA and the sixth-best starter’s projected ERA. The difference between those two numbers, over the 150 innings we’re granting our sixth starter in this scenario, will be each team’s cost of going to six starters.
Take the Royals, for example. Their best five starters — Brady Singer, Mike Minor, Kris Bubic, Brad Keller, and Danny Duffy — project for an average 4.70 ERA. Their prospective sixth starter, Jakob Junis, projects for a 4.87 ERA. That difference, expressed over 150 innings, is worth roughly three runs. Per my admittedly hazy math, the Royals might be better off with a six-man rotation even before considering the injury benefits.
With the caveat that all of this is ridiculous fantasy-land math that I did on the back of a not-particularly-large envelope, here’s how many more runs each team should expect to allow if they go to a six-man rotation next year:
| Team | ERA Gap | Extra Runs |
|---|---|---|
| Royals | 0.17 | 2.9 |
| Orioles | 0.21 | 3.5 |
| Angels | 0.24 | 4.1 |
| Giants | 0.27 | 4.4 |
| Rangers | 0.29 | 4.8 |
| Twins | 0.34 | 5.7 |
| Athletics | 0.35 | 5.8 |
| Phillies | 0.35 | 5.8 |
| Braves | 0.37 | 6.1 |
| Cardinals | 0.38 | 6.4 |
| Cleveland | 0.41 | 6.8 |
| Marlins | 0.43 | 7.1 |
| Tigers | 0.43 | 7.1 |
| Pirates | 0.43 | 7.1 |
| Brewers | 0.43 | 7.2 |
| Cubs | 0.43 | 7.2 |
| Blue Jays | 0.48 | 8.0 |
| Rays | 0.49 | 8.2 |
| Dodgers | 0.50 | 8.4 |
| Mariners | 0.51 | 8.5 |
| Reds | 0.52 | 8.7 |
| Diamondbacks | 0.59 | 9.8 |
| Mets | 0.62 | 10.3 |
| Red Sox | 0.66 | 11.0 |
| White Sox | 0.66 | 11.0 |
| Yankees | 0.73 | 12.2 |
| Astros | 0.75 | 12.4 |
| Nationals | 0.78 | 12.9 |
| Padres | 0.91 | 15.1 |
You might notice that the Rockies don’t appear on this list. That’s because if you asked me to project their sixth starter, I’d mutter “Hey what’s that behind you?” then run away when you turned to look. They obviously have someone detailed for that job, but I don’t find assigning it to any specific player particularly meaningful.
Do you want a solid takeaway from this article? Tough luck. Some of these teams could easily shift to using a sixth starter. Some would need to give up a little more. In no case is it a massive effect, depending on how you define the word “massive” — even the top-heavy Padres would only cost themselves 15 runs (roughly 1.5 wins) by adding a sixth starter, and that’s if there’s no benefit from an extra day of rest.
Will more teams shift to six-man rotations? I think so. It’s prudent — pitcher health is tenuous in the best of times, and while I’m certainly no biomechanical expert, extra rest meaning extra health hardly seems farfetched. It might help, performance-wise — teams probably have better data on this than I do. It’s cheap, runs-wise — thinning out the rotation is a matter of single-digit runs over an entire season for most teams. Weigh those three factors, and I don’t think Seattle will be the only team using this plan.
Update: This article has been updated to reflect the fact that the Tigers plan to start 2021 with a six-man rotation at least part-time.
Ben is a writer at FanGraphs. He can be found on Bluesky @benclemens.
If a starting pitchers need a 6-man rotation (thus pitching once per week) to stay healthy then I would postulate that starting pitching (throwing ~100 pitches) is not a healthy and sustainable activity. Instead, baseball should move to a pitcher-by-committee approach aka bullpen games (ignoring entertainment value for a second)
The only other sport where someone needs a full week of rest to recuperate is football, whereas baseball, basketball, and hockey all play more frequently and generally all the players play each game.
My point is thus: if you need a week to recover from a physical activity, you should probably stop doing that activity rather than just getting more rest.
I think baseball has, in fact, demonstrated that “starting pitching is not a healthy and sustainable activity”. 25% of active MLB pitchers have had Tommy John surgery (and that isn’t double counting people who’ve had it twice, counting other pitching injuries, or counting those that never recovered and were forced to retire).
Every pitcher is one bad day away from missing months or years to injury.
I did not realize the percentage was that high. I believe you, but would like to know more. Can you point in the direction of this data ?
Honestly, I don’t know who gathered the data; that number is just quoted everywhere. Google “percentage of mlb pitchers with tommy john” and you’ll find dozens of article with similar numbers.
An example from a reliable source: https://www.billjamesonline.com/tommy_john_surgery_in_major_league_baseball/
It goes deeper than that.
Professional sports in general is increasingly becoming a less healthy and sustainable activity as people push limits of human body.
Not saying professional athletes are not healthy, because they clearly are.
And teams are paying more attention to minimize injury, which is a good thing.
But fundamentally, the incentive to risk increased chance of injury for better short-term performance is too strong when millions of dollars are at stake.
“I would postulate that starting pitching (throwing ~100 pitches) is not a healthy and sustainable activity.”
It’s not. And we know it’s not. It never has been. Guys who have long careers of sustained success are, generally speaking the exception.
However, there’s still a pure numbers problem that makes going to full bullpen games impossible. The average team pitches ~1450 innings to pitch in a given season. Even if you factor in 15 pitchers, you’re still having guys throwing 90+ innings per year. And that’s with the additional strain of pitching on a greater number of days if you’re going to bullpen games. Which means more warming up, fewer rest days, etc. You would probably need to find a way to rotate through 20 pitchers to make that work, which also means finding 20 MLB quality pitchers and then having enough roster flexibility to do so.
There’s no form of pitching rotation that is really a sustainable and healthy activity. But I don’t see bullpen games being any better in that regard.
I am sure bullpens are worse. Half the guys in the pen are there because they can’t handle much of a workload – combine that with a 100% mentality and you realize why SP are important – they are the best of the best.
Need is not the question. The question is what’s optimal from a health and performance stand point. Pitchers don’t just pitch 2 games X days apart. They go through a season where varying degrees of injury are basically constant. Also the comparison to other sports is moot as pitching is literally a recipe for injury. It’s a very precise repeated task done at a very high intensity. Thats literally a formula for injury.
Pitchers would not magically stay healthy with a sixth starter or any other magical idea. There is 100 years of history that proves that it is OK to throw 100 pitches and throw every fifth day. Nobody ever does this, but look at the actual humans in the big, bad bullpens. They have short windows of effectiveness and extreme injuries. There is no real data to support the theories that this can be done better. People will create models and alter then to make them to support their ideas, but there is not real history of more effective pitching staffs or ways to keep people healthy. I am certain that 5 days is an adequate ammount of rest – history has proven so. How many times have you heard a SP complain that 5 wasn’t enough. They should be the ones we are asking. Power lifters rest a week between sessions – there is precedent for long rest periods but it should have intent… much as the 5 day starter routine does. This isn’t a real problem as much as an excuse for teams not attempting to build legitimate staffs.
Pitchers would not magically stay healthy with a sixth starter or any other magical idea.
Except in Japan. Although, admittedly, 5-man versus 6-man rotations is not an isolated variable in that case.
There is 100 years of history that proves that it is OK to throw 100 pitches and throw every fifth day.
There is not, however, 100 years of history that pitchers can throw at the velocity and torque that the modern game presents, and arm injuries have increased over time. Again, not a perfect variable set because we also know that many old arm injuries weren’t reported, and pitchers just sometimes washed out rather than have surgery. But, still, comparing pitchers 100 years ago to today when we’re talking about whether the human arm can survive the pitching motion is not even in the realm of an apples-to-apples comparison.
Nobody ever does this, but look at the actual humans in the big, bad bullpens. They have short windows of effectiveness and extreme injuries. There is no real data to support the theories that this can be done better.
You’re making a different argument now. There’s clearly a different set of variables affecting bullpen usage including up-and-down during a game, days’ usage, etc. Your point is getting farther away from 5-starters versus 6-starters.
People will create models and alter then to make them to support their ideas, but there is not real history of more effective pitching staffs or ways to keep people healthy.
Except, again, Japan.
I am certain that 5 days is an adequate ammount of rest – history has proven so.
Your definition of certain must be different from mine. And history hasn’t proven what rest is adequate for the velocity, torque, arm action, etc. we’re seeing today. It would be absurd to say that since seat belts don’t meaningfully change fatality rates in collisions at 20 mph, they’re not needed for safety on the Interstate.
How many times have you heard a SP complain that 5 wasn’t enough. They should be the ones we are asking.
Virtually every significant pitcher who has come over from Japan has made this point, and they are the ones with a comparison. American pitchers don’t know differently. There was a rumor – when Darvish complained and then quickly got quiet – that the MLBPA didn’t want pitchers talking about 6-man rotations because it would, in theory, decrease the purported value of each starter by depressing their stats other than on a rate basis. Completely unsubstantiated, as far as I know. It’s reasonable to understand, though, that most American pitchers who’ve only thrown every 5 days would want to stick with that routine, with all we know about athletes being creatures of habit.
Power lifters rest a week between sessions – there is precedent for long rest periods but it should have intent… much as the 5 day starter routine does.
Shoot, I have to rest up now when I coach my kid’s youth baseball team, because I’m older than I used to be. But I’m not more a good comparison to Noah Syndergaard than a power lifter is. The human arm is not designed to throw an object at that velocity and with that kind of torque, and as a result it breaks sometimes.
This isn’t a real problem as much as an excuse for teams not attempting to build legitimate staffs.
I assure you, arm injuries are a real problem. Players have a lot invested in their own careers, and owners often have a lot of money invested in the guaranteed contracts they hand out to established pitchers. Why shouldn’t both sides be looking to all avenues of ensuring that pitchers are durable for longer?
It is much more than just not getting hurt! It is all about maximizing value. How do teams get the most innings out of their best pitchers without sending them to Dr. Andrews? The fact that 6-man rotations are even being contemplated proves that nobody has figured out the equation, even after 145 years of organized baseball. The idea of limiting Jacob deGrom to 150 innings is ridiculous if those innings in which he isn’t where he should be are filled by Paul Sewage or Robert Gopherball. How does that help the Mets win? I can understand paying a stud $25-30 million but only if the the program includes a minimum of 200 innings. The way things are headed we may have seen the last qualifier for the ERA crown unless some bottom feeder keeps sending out some stiff to eat innings and he wins the award with a 6.27 ERA.
The answer is simple. Some can and some can’t and nobody has ever been able to predict if or when it is or isn’t going to happen.
Seems like the only reason to do it is if you have a very unique set of circumstances (like the Angels with Ohtani)
wat? the article suggests that a 6 man rotation could potentially prevent injury and increase starter effectiveness all without costing a team much in terms of wins. so, idk, kinda seems like theres potentially many reasons to do it.
How about more spot starts vs an actual 6th man in the rotation? A team like the Braves, Twins or Cardinals could then theoretically use their good starters as a 5th man all the time while pushing their worse ones back a day or 2 every now and then for spot starts to be preventative to injury? How do those factor in if you do one, I don’t know, once every 10 days instead of once through the rotation?
That may be what Boston means by managing workload. If a guy has a tough game with a lot of high leverage pitches, give him an extra day. Or maybe have three-four regulars and three rotating back enders sliding in from time to time.
I have a related thought. Trevor Bauer wants to pitch every 4th day. Some other pitchers are used to pitching every 6th day. Is there a way to have them both on the same team, doing their own schedules, and it would actually work for them and everyone else?
You can only baby a few players at a time in a staff. Those are generally 4 starters, but there are cases like MIL where they baby Hader. Everyone else gets sacrificed to try to keep them healthy. I think those people that you are protecting are ideally on the same schedule. Look at MIL specifically, they do keep Hader healthy but everyone else seems to suffer. Ideally you can protect 4-5 guys and its all part of the same plan. When those plans don’t coincide it becomes more unsustainable and more people suffer. Trevor Bauer is selfish and a very poor team player – no surprise that he wants his own plan regardless of whoever his teammates are and what is best for them. You can build a staff around only so many guys… by that I mean attempt to protect so many guys. Ideally the team is all part of one larger unit working together – I think the further from those guys being part of a 5 man rotation you get, the more you are tempting fate.
So, I guess nobody has figured this out. I’m just thinking through this–if Bauer pitches every 4th and Ohtani pitches every 6th, can you design it so that (a) everyone else pitches every 5th game and (b) any deviations from the every-fifth-day-schedule don’t screw everyone up?
During the years that RA Dickey and Tim Wakefield were at their peaks, I always wondered if a team could have them pitch game 1 of every series (3 games or longer) during the season. That’d be a crazy 50+ starts for the knuckleballers. Does RA Dickey go 30-9 with 350IP in 2012? I wouldn’t think it would be that difficult to maintain a stable pitching schedule for the top half of the rotation, however the back half of the rotation would constantly have starts skipped and pushed back (benefit?). Added bonus: Opposing teams have to face a knuckleball with the anecdotal “screws up their timing at the plate” for the next couple days affect.
I’m still waiting for a pitcher with mlb caliber stuff who also throws a knuckleball.
Tom Candioti
Phil Neikro threw 44 starts in 1979 and many were complete games! he won 21 and lost 20!
Edit: screwed up, disregard.
I had the same thought, so I sketched out a basic approach for a 6 man rotation. TB = 1.
1, 2, 3, 4, 1, 5, 6, 2, 1, 3, 4, 5, 1, 6, 2, 3, 1, 4, 5, 6 … (sequence repeats after 20 starts)
In 20 total games, Bauer starts 5 times on a regular schedule. Everyone else starts 3 times, once with 5 games between starts and twice with 6. So that discrepancy is one issue that is immediately apparent, and that’s before we account for off days. I suppose you skip someone to deal with that and get them other work so everyone is more or less on schedule. Would pitchers (other than Bauer) be okay with a different number of games between starts? Would they be okay, when they get skipped, with an extended gap between starts?
Upshot:
Bauer starts 5 times, with 3 games between each start
“2” starts 3 times, first with 5 games between, then 6, then 6 (into next chunk of sequence)
“3” starts 3 times, 6 games between, then 5, then 6
“4” starts 3 times 6, 6, 5
“5” starts 3 times, 5, 6, 6
“6” starts 3 times, 6, 5, 6
For a 5 man rotation, on the other hand, it’s even more irregular and involves routinely starting guys on short rest:
Bauer = 1, Ohtani = 2
1, 2, 3, 4, 1, 5, 3, 2, 1, 4, 5, 3, 1, 2, 4, 5, 1, 3, 4, 2, 1, 5, 3, 4, 1, 2, 5, 3, 1, 4, 5, 2, 1, 3, 4, 5, … (sequence repeats after 36 starts)
So starters 3, 4, and 5 have to pitch with 3 games between, (for instance, 3rd starter’s first two starts), 4 games between, (3rd starter’s second and third starts), 5 games between (3rd starter’s third and fourth). Doing that does allow Bauer and Ohtani to stay on schedule, though.
Upshot:
Bauer starts 9 times on regular schedule (3 games between)
Ohtani starts 6 times on regular schedule (5 games between)
“3-5” start 7 times each, with highly variable rest
WHY CAN’T I POST GIFS AS COMMENTS??!!
Because that would make this site worse.
*insert “Why not both?” girl*
Between shorter outings and the potential of fewer starts we’re headed for a world where good, healthy, starting pitchers are gonna be slotted for 160 innings. These decisions are made to win but you can’t help but feel this furthers contributes to the entertainment deterioration of baseball.
I’m not saying we know this to be the case… but if pitching every 6 days and throwing 160 innings reduced TJ surgeries and other injuries by a significant number, I would take that over pitching every 5 days and maybe throwing 200 innings or maybe blowing out an arm. I’m obviously taking a convenient path to my point, but I think the increase in arm injuries also contributes to the entertainment deterioration of baseball, and I’d rather see good pitchers pitch 6 innings every sixth day with less injury risk – if that were indeed the case.
I do wonder if there is any difference between throwing 160 or 200 ip in a given year for pitchers health. Do starters who go deeper in games tend to take it “easier” and thus are able to go deeper? Or is it survivor bias? Or is it just random. I did read recently that “ace” level pitchers over the age of 34 tend to be the safest subset of mlb pitchers in regards to performance. Again, I guess who knows.
If we had far fewer arm injuries then the quality of the average pitcher should go up!
What is the cost of having one fewer man in the bullpen? It seems that would happen with a 6-man rotation, unless a team has a couple 6th starters they can shuttle back and forth between MLB and AAA.
I did an analysis of relief pitchers vs. starters a few years ago as a fan contribution to this site, and concluded that a pitcher’s roster spot is worth roughly 1% of a win per appearance on average (I’d use someone else’s number for the value of a roster spot since I’m not too impressed by my methods, but I don’t know of anyone else who’s assigned a value at all).
Given that this value was based (mostly) on reliever appearances, and that a good reliever sees an appearance at most roughly half the games, this gives a roster spot a maximum value of less than a win per season.
Roster spots have value, but probably not enough to move the needle too much.
The cost is zero. This person is the least valuable player on the team, with the exception of maybe a backup catcher. In reality, your 6th starter will not be a real starting pitcher by any real definition – he is your extra RP listed as the starter on a team without much of a rotation.
Kinda surprised to see this article without a discussion of how this works in Japan. Teams play six games a week, Monday through Saturday. They use six starting pitchers. The roster size is larger, but the manager designates certain players as ineligible every game (usually including yesterday’s starter and tomorrow’s projected starter). Some Japanese pitchers swear by this approach; it is one of the hardest things for them to get used to when they come to MLB (other than the ball itself).
Japanese players have a much, much lower rate of Tommy John surgeries though 5-man versus 6-man rotation isn’t the only variable to measure.
With all due respect to Ben, here’s an older Rob Arthur piece on the topic:
https://fivethirtyeight.com/features/are-six-man-rotations-ever-worth-it/
There was a lot of discussion on the topic when Tanaka and Darvish each came over, and it was also covered in Jeff Passan’s book The Arm.
FG is for new ideas for progressive baseball fans. If you think FG content is based on real baseball and historic precedents, then you shouldn’t. In fact, everything from the past is in fact stupid and regressive. Japanese baseball is a fundamentally different game as well. They are much better pitchers with less emphasis on stuff. I would argue that is the source of arm health. They almost always come straight to MLB and have some success – I think we can conclude that they are better at the art of pitching. It is also relevant that those pitchers that come over are often times damaged goods – not a lot of fresh arms… they do tend to hang around for quite a while and pitch effectively which I think is further testament to mastery of their craft.
Your posts are very confusing.
They almost always come straight to MLB and have some success – I think we can conclude that they are better at the art of pitching. It is also relevant that those pitchers that come over are often times damaged goods – not a lot of fresh arms…
Which is it? Better at the art of pitching, or often times damaged goods? I think those two things are mutually exclusive in that being better at the art of pitching should help prevent one from being damaged goods.
Don’t Japanese pitchers also throw a lot more in-between starts?
6 man rotation. Openers. All are slight of hand for failure to either develop or sign 5 capable starters. Teams that use a lot of openers flat-out annihilate their arms. 5 starters has proven to be effective and sustainable but that was in an era that developed starting pitchers. This era is defined by cost saving measures, which hurts SP development. While I generally like the idea of keeping people healthy and more SP, this won’t make them any healthier. a 5-man rotation was the result of many decades of experience and data. I doubt that more rest simply fixes injuries – it might but I do’nt think it is a given. A six man rotation probably doesn’t give enough innings to the elite players that really should be learning to be masters of the craft. That is why we don’t have many real aces these days – its because we don’t give them the opportunity. Much like a platoon bat will never be an everyday guy, a SP that does pitch enough innings will never scrape his true ceiling. The best SP are not always eye-popping velocity guys, they are simply great pitchers and that only happens through throwing a ton of innings. 6 starters guarantees that players won’t be throwing a ton of innings. History is filled with SP that have thrown a ton of innings. If you don’t give them a chance to identify themselves, then you will never figure out who they are and you be left with a bunch of frauds attempting to play the part. The fact that MLB is not developing starting pitchers is a disaster. Perhaps the sixth starter gives more innings per start, but I highly doubt it leads to more innings. It sounds like another excuse for having AAA arms throwing MLB inning. The fact that an algorithm can’t quantify that, does not make it more justifiable, its just more cost-saving smoke and mirrors. I imagine that the same silly progressive baseball ideals would still exist and these pitchers would not only start fewer games but also get pulled early #blakeSnell. Its fitting that you point out that DET is going with a 6 man rotation – they don’t have a pitching staff and have done nothing about it.
Yep, and NFL’s decades of experience has made concussions not an issue for them. There is a chance that 5-man rotations is (was) the sweet spot, but more than likely it was used to maximize using elite pitchers without much consideration for health (i.e. data wasn’t consulted). The development of more pitchers (especially high velo pitchers) has likely changed what the sweet spot regarding performance and health from when the 5-man rotation was developed.
Granted, I’m not sure a 6-man rotation is the answer.
I feel like 2 or 3 starters per team, and multiple bullpen games is probably the best strategy.
In 2019, the top 90 pitchers in the league (by innings pitched) averaged under 174 innings (note that 90 is 3 per team). The Rays pitched 1474.1 innings, and everyone was at least close to that.
Three starters thus leaves ~952 innings to cover with the bullpen. The top 100 relievers (assuming these to be the heavily used ones) averaged a hair over 67 innings each. Dividing, it’s a bit over 14 relievers per team to do this.
You don’t have the roster space for 3 starters and 14+ relievers. Which means that you’ll need to be rotating relievers in and out of AAA and AA to keep this up, which means that the relievers being sent down and called up will cover fewer innings than the top relievers’ sample space, which means you need something like 20 MLB quality relievers to even think about pulling this off, or you need some relievers to pitch a lot more innings than is currently asked of any reliever. (Mike Marshal of 1974 says “Hi, it’s possible to do that, but no one does it in the 21st century.”)
A noble spirit embiggens the smallest pitcher
I think an important matter is who this sixth starter would replace on the roster and the implications that would go with it. Would he replace a batter or would he replace a reliever?
If he replaces a reliever, the workload for the relief corps would be bigger. Or will there be more multi-innig relievers (this question seems especially important with a potential universal DH).
So my conclusion would be that a sixth starter might be the beginning of the end of starters being used for fewer and fewer innings: The relievers need rest, too. If you take one guy out of the bullpen, add a sixth starter, but you don´t use your starters for more innings, the bullpen will have to cover more innings.
Bring in a sixth starter, increase the workload of the starters per game and work balance between starters and relievers will be fine again.
I agree, but only with some of that.
It’s not just that fewer relievers will be splitting the same work. Given the likelihood that SP6 will require more bullpen support in his starts, you’re actually talking about fewer relievers splitting MORE work.
Honestly, with the steady decline in how long even the top-5 starters go in games, I feel like this is an inevitability regardless.
Running a AAA reliever shuttle might work for some teams, but too much of that will be the dregs of the talent pool, and that’s not helping anyone to win games. Not really.
Multi-inning RPs seems like a pretty obvious solution. If a team is able to roster a couple of arms that can go once through the order every 2-3 days, that would ease the strain on those that can’t. But who are those guys, really? Well, they’re mostly depth starters serving some time in the pen for one reason or another, or relievers who only very recently were starters.
It’s a very short walk indeed from that to … TANDEM STARTERS!
Multi inning RP would be the logical solution in the American League. But what about the National League, if there is no universal DH?
The universal DH will be here before starts are uniformly short enough that multi-inning relievers are entirely necessary. Or, the need for the same might be part of what drives the adoption of the universal DH
A six man Rotation only works if you don’t care about winning because your best pitchers will throw less innings and you pitch a bad guy once a week that usually wouldn’t pitch.
You also lose a pen spot.
As you stated the individual pitcher does get slightly better with an extra day of rest but not enough to throw your 2 era ace 30 innings less and your 5 era 6th starter a lot more.
There is a reason why only tanking teams are doing it.
Is there an impact on average IP per start? Or pitches thrown? Perhaps more rest enables pitchers to stay in longer, making the innings difference over a year less than 30 for star pitchers
The article is interesting in that it speaks of another approach to a conundrum that has been a huge part of baseball since Hoss Radbourn threw 73 complete games in 1884 on his way to tossing 600 + innings for the second year a row. What is the best way to keep the pitchers on the field and effective to get the most value out of them? Having been an avid baseball fan for nigh onto 75 years I have seen more of the evolution than most on this site. I am seen as a dinosaur because I refuse to adhere to some modern ideas about protecting pitchers arms. The claim that the great pitchers from the 50’s, Roberts, Newcombe, Reynolds to name a few, in the 60’s Gibson sticks out then Seaver, Ryan, Carlton, Palmer and more from the 70’s didn’t put it all on the table when they pitched is malarkey. Who could ever say that Gibson ‘s distinctive follow-through wasn’t simply the result of the maximum effort that he put into every pitch. Those were the days before TJ surgery and lots of arms fell off, but just as many, or perhaps even more, fall off today except they can now be reattached. I grew up in the era of 4-man rotations. The Dodgers in 1966 never started a pitcher other than Koufax, Drysdale, Sutton and Osteen during the entire season and only 5 others appeared in 10 games or more. Some interesting facts include the 1972 White Sox getting over 40 starts from 3 different pitchers including Wilbur Wood who is probably the last pitcher to start over 40 games and he did it 5 years in a row. The 5 man rotation was taking over the game and has been the standard for around 50 years. The question I am asking is, and is being asked today, has this benefitted the health of the pitchers and has it maximized their value? Simply talk of the 6 man rotation proves that nobody has an answer to the best way to maximize the value of the best pitchers. Nothing, and I mean nothing, has shown me anything to indicate that throwing fewer innings is an effective way to keep an arm from breaking down. I guess if Jacob deGrom never pitched then he wouldn’t get hurt and that appears to be the only response that is coming from the teams. Let’s not use him so he doesn’t get hurt. There is absolutely no way of predicting whose arm falls off. Karl Spooner might have been the greatest ever but we never got the chance to find out. Mark Prior was supposed to have the perfect delivery. A lot of good that did him. or how the hardest thrower the game has ever seen, Nolan Ryan, could continue to do things that will forever be unchallenged over a career that spanned 27 years. Should teams take the risk to find out if Jacob deGrom, with a perfect build for a pitcher and as graceful a delivery as there is, be another Gibson or Seaver or Ryan? Having seen so many great pitchers of yesteryear do just that, I am of the belief that he could do it. Anything less than 30 decisions is a crime against Jacob deGrom, against Mets fans and against baseball. The Mets would be so much better if he was on the bump for 250 or innings a year instead of anybody else. Returning to this latest “idea?” of now a 6 man rotation, the only change I can see is that it drops the value of starting pitchers significantly, in no way answers questions about its effect on pitchers health and usage and is just another wild stab to try to solve a problem that has no solution. What causes an arm to fall off? That has been discussed in various different ways forever. It was breaking balls, sorry, it’s the splitter, sorry again, no it is high velocity, no evidence there either but every person on the medical staff, in the training room and front office will continue to try to find that magic glue as they have tried for the137 years since Old Hoss toed the slab.
Even though the team is still called the Indians for another year you can’t handle using it in your articles. How long until the Braves name gets pushed out and become just Atlanta here I wonder.
Good lord. Maybe Dolly Parton said it best when she had a ride at Dollywood renamed: “There’s such a thing as innocent ignorance, and so many of us are guilty of that. When they said ‘Dixie’ was an offensive word, I thought, ‘Well, I don’t want to offend anybody. This is a business. We’ll just call it The Stampede’. As soon as you realise that something is a problem, you should fix it. Don’t be a dumbass. That’s where my heart is. I would never dream of hurting anybody on purpose.”
There is nothing wrong with the word Dixie either. It is a term that refers to a geographic area. Will the term, the south, be deemed offensive as well?
Come on. The n word is a term that refers people of a certain skin tone. Would you make the argument that there’s nothing wrong with it and that we’re on the way to saying ‘black people’ is offensive?
There was never a positive association with that word. It was always a negative term. Any more most seem to agree that nobody should use, while some say that only certain people can use that term. That concept doesn’t make any sense either.
“In 1982, 50 pitchers threw 200 or more innings. In 2019, only 15 hit that threshold.”
This made me sad as a fan of baseball, not gon lie.
Performance issues of varying days of rest aside, there’s a strong case to be made that rebuilding teams should opt for evaluating as many starting pitching prospects as possible. The long term cost reallocating veteran pitchers’ innings for the bottom 10 teams is probably positive with the expected performance drop off of ~5 runs over a season worth development or evaluation of an additional starting pitcher.
Dumb idea, but what about guys not throwing 100% effort as often? Will that cause more injury?
My thought is, everyone gets 1 time through the lineup and they throw less hard. Every third day
In the old days, “That was the Way”.
Not going all out on every single pitch, that is.
Four man rotations, 300 innings, complete games galore.
95mph was notable, not common; 100 a wonder.
But that was before strike zone shrinkage, PEDS, biomechanics, game video (in-game and out) and massive contracts that make even a journeyman 5 year career worth a lifetime of comfortable living afterwards. Even one-pitch relievers can acrue decent fortunes before they break down. That’s a risk most take with clear-eyed awareness.
Some things, like biomechanics, can’t be unlearned.
And the stakes are much higher.
The days of veteran major leaguers needing an off-season job are decades gone. Today the off season job of everybody with even a year service is conditioning and fine-tuning.
Different times, different game.
I think a six-man rotation would have value for a team that isn’t a contender, and wants to spread the workload to see which of it’s pitchers could become quality starters. For a contender, not optimal to lessen the amount of innings for your studs while giving starts to weaker pitchers. There is a reason that teams only use three starters in the playoffs. With starters rarely going over 100 pitches nowadays, I find it hard to believe that an extra day of rest is needed or would minimize injury risk. The Japan model is interesting, however I believe their pitchers throw much more between starts than MLB guys do.
Thank you for using the word embiggened
And why wouldn’t they? It’s a perfectly cromulent word…
There was a good article in The Book about 5 and 6 man rotations. They also had an interesting suggestion about how to use the 4th and 5th man. It was kind of piggy backing.
I always wondered why I didn’t see teams try it. The Rockies gave it a go a few years ago, but it didn’t work, although Coors Field probably didn’t help
Would love to see the Angels sign Bauer, have Bauer pitch as part of a 4 man, and Ohtani do the 6 man. That works, right? Who knows if it will work, but I’d certainly love to see it.
Could be done. Say you want Bauer on 3 days rest and Ohtani on 5, pitchers A, B, C, and D on 4 or more. Ignoring off days and double headers: your rotation might look like this.
Bauer; Ohtani; A; B; Bauer; C; D; Ohtani; Bauer; A; B; C
Then rotate around to the beginning again.
This requires “A”, “B”, and “C” to alternate between 4 days rest and 6 days rest which may or may not bother them. With a well timed off day, you can maybe avoid ever actually using “D” as a starter.
This is the type of approach that seems to be worth looking at. Where is it written in stone that every pitcher has to follow exactly the same routine to be at his most effective? It is reasonable to think that some might be best on 3 days rest, Bauer seems to want to do that, and there are certainly others who would benefit from more rest. There is history to support this. Hall of Fame member Ted Lyons, for the last 8 years of an illustrious career that lasted 21 years, was the designated Sunday starter for the White Sox. In those days most teams played a Double-header on Sunday and Lyons would start the first game. For example, in July,1939, Lyons started on the 2nd, 9th, 16th, 23rd, and 30th. The rest of the starters had to adjust to fit into this locked in situation(tradition). Ohtani would seem to be a perfect candidate for a similar approach.
Another huge point against a 6 man rotation is you could never sign a good free agent pitcher. All the top starters would refuse to sign as a free agent, if they were told they would only start every 6th game. And imagine the current top starters…..what would Gerritt Cole or Shane Bieber or Jake deGrom say ? WTF ? that is what they would say. It would piss them off big time. I believe it would be a bad move for a team to use a 6 man rotation. Here is another example. Brandon Woodruff is having a bad game. They have to pull him after 3 innings. And now he waits another 6 days. So in 12 days he pitches 3 innings. I think it is a very poor strategy.