While writing about the four man rotation last week. I wondered about the medical side of the decision and how that may come into play. So I spoke to Dr. Glenn Fleisig of the American Sports Medicine Institute,one of the foremost experts on biomechanics in the world about the four man and how it relates to the Rockies. Many thanks to Dr. Fleisig for his time.
(Note: I asked Dr. Fleisig about Coors and altitude affecting pitchers arm health and workload but he declined to discuss it as it is outside of his expertise.)
The four man rotation doesn’t necessarily change the starting pitcher’s workload, it redistributes it. With a league wide average of about 16 pitches per inning for starters, if a team gives a guy an 85 pitch limit, an average pitcher is going to go 5.25 innings pitched per start, which ends up being 210 IP, 3,398 pitches thrown in the 40 starts a 4 man rotation would give. Would this redistribution of a given amount of pitches help or hurt the health of a pitcher?
Dr. Glenn Fleisig:
I have some opinions; I don’t have concrete answers on this. The things to know here are that you can’t just count the number of pitches or the number of innings. 200 innings pitched this way and that way do not mean the same things. It would be the same thing if it was like a bucket of apples and you kept taking an apple out every time you pitched an inning and either way you would run out of 200 apples, or bullets as they say. But our arms are not that way, the pitchers and their arms are living, breathing people. They are living and what that means is that they get damaged as they do athletic activity and they get repaired when they are resting and recovering. So in an extreme case, pitching one inning a day for 200 days in a row is certainly different than 200 full effort innings on one day. So from an extreme you can’t just add up the numbers, which is you question, do they add up the same? No.
So now the question is which is better, is it beneficial or is it worse? So if you are going to pitch 200 innings, is 110 pitches every 5th day how does that compare to 85 pitches every 4th day? Let’s assume we are starting with healthy pitchers with no history of problems. What is happening is that when you pitch, your muscles move your body and your bones, and your ligaments and tendons have to basically withstand the force your muscles made. During this activity, every single pitch, the ligaments and tendons (elbow and shoulder) endure this force and there are microscopic tears. Over the course of 85 or 100 pitches you have more tears after 100 pitches than 85 pitches. The Tommy John ligament and the rotator cuff are essentially like elastic rubber bands. When you pull a rubber band or something elastic really hard it gets to the point where you get permanent little tears in it. That is what is happening in ligaments and tendons. What is happening is that at the 85 pitches you have a few tears and at 100 pitches you have a few more tears. And then when you get the four or five days to rest, including having a bullpen in between, your body is recovering. While your body is recovering those little tears are essentially repairing. You have blood flow and it repairs the tendons and ligaments. (For what it is worth the muscles also get tears but they repair a lot faster, but ligaments and tendons don’t have such great circulation so they are not great at repairing). So the real question is: for getting through a whole season successfully, is that each time you take the ball and go on the mound for the first inning you want to be starting with a clean slate with the ligaments and tendons, you don’t want residual tears from pitching. Because what happens is that if you pitch a good amount one day, and then you don’t rest enough and you go pitch the next time a few days later you start with little tears already and your new tears are going to add onto your existing tears, and then you do it a few days later, and again, and later your elbow or your shoulder is going to snap. You are going to feel it on a bad pitch, but really it was an accumulation that was building up. The little tears from day one and day five, they started adding up.
There is no exact equation saying the damage from 85 pitches takes exactly 4 days to repair and the damage from 115 pitches takes exactly 5 days to repair. There is no exact equation either medically or physiologically or in practice because there is huge variation from one person to another. Some people make good short relievers and can pitch every few days and some guys are starters, and some guys can flip flop back and forth like John Smoltz and some other pitchers that have been converted back and forth, but some guys really struggle converting. Some starting pitchers never do well in the bullpen, they take too long to warm up and things like that. What is happening is that each person’s body is a little different as far as how fast you damage and how fast you repair. What effects it is genetics, if you pick the right parents essentially, and also what you eat and drink, the vitamins you take, etc. That is where steroids come into play, the artificial helper, and what they do is help you heal quicker. How soon again you can pitch depends on your genetic makeup and what you do duringyourdays as far as exercise and nutrition. So the answer is unfortunately, in my experience one pitcher would be better off being in a four man rotation of 85 pitches and some other guy might be better off with 115 pitches every fifth day.
What the Rockies are trying to do, this trial and error thing is a worthy experiment, because there is no proof that a five day rotation is better, there is no proof the four day rotation is better. It really is trial and error because of all of the things I explained about how ligaments and tendons tear, that is all science but then there is the art and the feel of knowing your individuals and making your system fit best for your individuals.
As a researcher yourself, how long do you think you would have to do the test for before you could say that the four man rotation might be imperiling the health or that it might be helping since you never know in any given situation whether an injury would have happened anyway under the five man rotation?
Scientifically I can tell you that it is preposterous. To prove it would be better, but I would have to set up an experiment where let’s say probably about 200 pitchers in a four man rotation and about 200 pitchers in a five man rotation for a season to see if there is a significant difference. So to have one team do a four man and one team do a five man wont prove anything. It not unlike judging two batters who bat 15 times in a weekend and one goes 7-15 and one goes 3-15, did you really prove that the first guy is the better batter? No. So the sample size of one team doing it for one season is just like a blip, you can’t prove it. So in my opinion, it is worth trying. It is worth trying a four man rotation, it is worth staying with a five man rotation, there is no inherent sign saying one way is better than the other. But if they do it and some guys get hurt or don’t get hurt, it really didn’t prove it right or wrong. The press will say “look you guys messed up or you guys did a good job” but [the team] won’t even know in their heart, and scientifically they won’t know because things happened.
I was interviewed by a Toronto reporter after they had like four guys go down with Tommy John surgery. They asked me “what did they do wrong?” Maybe they did do something wrong. But maybe they were the blip. So the Rockies doing this; they won’t be able to prove or disprove it was a good decision. But that being said, if they can do it right, I think they are just as good trying a four man as a five man, there is no reason that one way would be better than another, except by habit and that is what everyone else has done.
So if it was given that the Rockies were going to go with the four man rotation you would not necessarily recommend using a certain pitch count, correct?
Dr. [James] Andrews and myself were intimately involved in establishing the pitch count rules in Little League Baseball throughout the country. But even though we are the scientific background for why there are these pitch count rules, I really believe there should not be a pitch count rule for Major League Baseball, and there isn’t obviously. In a four man or a five man rotation they should definitely utilize pitch counts as one piece of information. And also performance, and ball velocity, and those things should be other pieces of information. And a big piece of information, it’s not mathematical, is the human feel: the feedback from the trainers, the player, and the pitching coach… how is it going, is it struggling of is it going well? That is a very important part which is hard to quantify, certainly for outsiders. And the other part is their mechanics, whether they have good or bad mechanics as they progress. And the other thing that has to change is what they do on the off days of a four or five man rotation. Right now some teams do the bullpen on the second or the third day after the start and the day after they pitch they usually have no throwing. Each team has a little different program. But obviously they would have to change their five day cycle to be a four day cycle and would have to consider what program they want to try with the four man.