Six-man rotations have always interested me. Baseball has evolved to the point to get the modern five-man rotation we see today. Even not too long ago, at least relative to baseball, we had four-man rotations. The next logical step from here has always been six. My curiousness about it has come from how certain Orioles pitchers seemed to do better with extra rest and it’s even more interesting now with Orioles now having six major league ready starters.

I had a conversation on Twitter the other day that was thought provoking. Twitter? Thought provoking? Shocking, I know. But this conversation was with someone who actually knows his stuff, Mr. Will Carroll. Mr. Carroll covers medical issues in and around sports, he’s written for Fan Duel, Baseball Prospectus, Bleacher Report, and Sports Illustrated, and he was given a MORE Award by the American Academy of Orthopaedic Surgeons for his story on Dr. Frank Jobe.

So, I decided to follow up our conversation with an interview. Twitter almost never the place to get well, though out answer because of the 140 character limit. I didn’t want Mr. Carroll to be limited when I asked these questions. I wanted to hear everything he had to say. I want to thank Mr. Carroll for his time and being the spotlight of this article.


Q: One of the arguments for a 6-man rotation is that pitchers normally perform better with that extra day of rest. Orioles’ Pitcher Miguel Gonzalez being an example of that with an ERA of 3.67 on four days rest as opposed to his ERA of 3.03 on five days rest. What are some ways players could manage that fatigue in order to simulate that extra days rest without having to be in a 6-man rotation?

A: “You could cherry pick numbers from either side. For decades, we had great pitchers in a four-man rotation. Some pitchers pitch better on short rest. You’re equating recovery with days, which is a false equivalency. Since we’re not measuring fatigue, the question falls apart. Let’s start with that – measuring fatigue directly will show us a lot more than just counting out days.”


Q: One of the largest issues behind the use of a six-man rotation is it shortens to available players out of the bullpen and/or bench.  Buck Showalter has commented in the past on the possibility of a 26-man roster to assist with this tactic.  Is there any chance the MLBPA would be interested in considering that as part of their bargaining position during the next contract negotiations?

A: “So we have to change the entire game in order to make this work? It will cost each team an average of three million, reduce the quality of pitchers, and there’s no evidence it will decrease injuries? Wow, I’m sure every team will rush out to sign up!”


Q: With the increased focus on pitching injuries, the discussion of moving to a six-man rotation to give additional rest has been discussed by players, including Yu Darvish who is familiar with the practice in Japan and Korea. Is the reasoning behind this argument an effective one and could be of benefit to preventing pitching injuries?

A: “Well, Japan doesn’t use a six-man rotation per se. They pitch in one game a week and will use up to six pitchers, but usually scheduling takes care of things. This is really more about usage and recovery than the six man itself, so no, I don’t believe we can take anything away from it. Add in that the Japanese and Koreans do far more side work and I think it becomes even less a point of comparison.”


Q: The Orioles have had a rash of injuries to their top prospects. Currently, their only top 100 prospects (Bundy and Harvey) are shutdown with injuries to their shoulders and elbow respectively.  For an organization that has employed Rick Peterson to monitor biomechanics, why do the Orioles continue to suffer in maintaining the health of their top prospects, but also in their ability to develop them? Does the organizational philosophy of not letting young pitcher throw cutters play into that?

A: “The cutter thing is overblown. Study after study shows pitch cost is individual and variable, at best, if it even exists. I think what we have to look at is that injuries are cumulative. Unfortunately, youth and scholastic pitchers see some of the worst workloads around and that’s only getting worse. Dr. James Andrews has seen his under-21 surgical load go up to nearly 25% of his Tommy John surgeries and that holds true for many of the other top surgeons. So fact is, Bundy and Harvey were likely broken when they got there.”


Q: What are your thoughts on the TB Rays installing Kinatrax and how much that costs and why wouldn’t other teams make that investment now? With the Kinatrax equipment being installed into their stadium, what’s to stop the Rays from using it on the opposing team and use the data against them? Is that even legal?

A: “There’s nothing to stop them from using it, aside from Rob Manfred. Teams on the whole don’t invest anything in research. Few use biomechanics, few do research of any kind.”


Q: The Orioles are one of the top defensive shifters in baseball, leading the league the past few years. It has also been a hot button topic with Commissioner Manfred thinking about possibly banning it. Do you believe that shifting is just gimmick? If not, do you think hitters will ever evolve far enough where shifting won’t matter?

A: “No. I believe positioning is just the beginning. With Statcast tracking, I think we’ll be able to not just move players from one side to the other, but to calculated positions based on probabilities and range. At that point, teams will have to have sets and better communication to make that happen quickly enough.”


You can find Mr. Carroll here on Twitter and you can find his work here, here, here, and here.