Age-old tactics: Why does every team use a five-man rotation?

The other day I was watching Barry Zito pitch for the Giants -- you know, Zen demeanor, floaty curveball, fastball that reaches at least the mid-70s -- when it occurred to me how much happier I'd be if I were instead watching Tim Lincecum pitch.

Not that this is a knock on Zito (at least not entirely), who has been surprisingly effective of late for the Giants. Rather it's an appreciation of Lincecum. He strikes out more than a batter an inning, his WHIP is close to 1.00 and he's lost all of 14 games in his career. He's the best pitcher in the game. Even Barry Zito's dad, if he were being honest about it, might rather watch Lincecum pitch.

But since it was Zito's turn in the rotation, Zito is what I got. Which led me to wonder why, exactly, this must be the case. In an era of sabermetrics and biomechanics and advanced baseball thinking, why is it that every team in baseball deploys its starters in essentially the same fashion? Every team uses a five-man rotation and, when they don't, as in the case of the Yankees and their creative handling of Joba Chamberlain (the "Joba Rules"), the impetus for the rejiggering is based on injury prevention. The Yankees want to limit Chamberlain's innings now to preserve his future, both near-term (so he's effective in the postseason this fall) and long-term (so he's effective for many falls to come). That's certainly an admirable goal, but it's one based in preventive strategy.

Why not instead be proactive? Consider the following scenario. During spring training, or the offseason, or better yet at the minor league level, a team does a full breakdown on all its pitchers. Using a three-pronged evaluation from a medical, biomechanics and statistical perspective, the team attempts to determine each pitcher's optimal recovery time for optimal performance (which is to say, how much rest they need to be their best). Since all human beings are inherently different, and last time I checked pitchers are human beings, there has to be some variation based on age, arm motion, types of pitches thrown (say, knuckler or junk pitcher vs. power), genetics and a host of other factors. It doesn't seem likely, or even possible, that every starter in baseball would be most effective on the same amount of rest. That's like expecting everyone to metabolize alcohol at the same rate, or to function the same on five hours sleep.

The evaluations could tell you a lot. With an extra day of rest, maybe certain older pitchers would maintain their velocity better, or have an ERA half a run lower. Maybe you'd determine that certain power pitchers -- I'm thinking guys like Roy Halladay and CC Sabathia -- are just as effective on three days rest as on four, with no deleterious affect on their health, provided they are on a pitch count. (And that is important, for baseball wisdom now holds that is not throwing a baseball that hurts a pitcher's arm, but throwing a baseball when the arm is fatigued that leads to damage).

Taking that information, a team could put together a rotation where some pitchers took the mound every fourth day, while for others it was every fifth or sixth. The result: a starting staff where marginal pitchers are used less often, or at least when they're most effective, and better pitchers are used more often. The ripple effect of this would be tremendous.

Take the example of Lincecum, who is young and efficient in his outings (thus limiting pitch counts). Let's say his body were built so he could pitch on three days rest without much dropoff or long-term health problems. The Giants could then modify their rotation so that Lincecum got another half dozen starts or more during the season. If he were feeling fatigued when that shortened start came around, well, that's why you have guys like spot starter Joe Martinez on the roster.

The most obvious result, presumably, would be in the standings, where a half dozen more starts from Lincecum (plus perhaps a half dozen from another young pitcher like Matt Cain) would likely lead to more wins, while at the same time limiting the damage from the fifth starter, who is now pitching on six days rest and is theoretically more effective. Second, you'd increase attendance. People (like me) want to go to Giants games when Lincecum is pitching. And because the rotation would be fluid, ticket buyers couldn't plan ahead just to specifically cherry-pick dates when the ace was pitching. This equals more walk-ups.

The obvious counterargument is that teams, and agents, wouldn't want to blow out their stars' arms. But who's to say that would necessarily be the outcome? After all, that's why the team performed the diagnostic tests. And I'm by no means an expert but I haven't seen any evidence that says it's the frequency of pitching that is in itself dangerous -- if that were the case, then Mariano Rivera would have had his right arm amputated at the elbow years ago, as would every other big-time closer. Clearly, humans can pitch most every day, and effectively, if managed correctly.

Then there are the fringe benefits. For the agent, his pitcher just got 6-8 more starts than the rest of the league, which means a better opportunity to rack up wins (rightly or not, an important factor in Cy Young voting), not to mention a platform to be seen as invaluable and a workhorse, two qualities fans and sponsors love. For the team, it makes it difficult for opponents to predict pitching matchups. And, come playoff time, one or two of your best pitchers would already be accustomed to pitching on "short" rest, gaining an advantage in a series matchups. For the life of me, I couldn't imagine why a team wouldn't give it a try.

Yet since no team does, I figured there must be a good reason. Surely someone could blow holes -- large, Prince Fielder-sized holes -- in my theory.

So I called Dr. Glenn Fleisig, the director of research at the American Sports Medicine Institute. Fleisig is on the cutting edge of pitching biomechanics, working closely with Dr. James Andrews, who you may know as That Guy Who Performs All Those Arm Operations. Each year, five to 10 major league teams send three dozen or so pitchers to the lab at ASMI. The goal is to identify potential flaws that could lead to later injury.

Fleisig is an eloquent, cordial man and he patiently explained to me how arm and shoulder injuries occur (microtears in muscles, ligaments and tendons that can snowball if not given proper recovery time). He explained how pitchers know when they're getting these microtears (when you feel sore or fatigued, "your muscles are saying, 'You might want to stop playing sports.'") And he explained how he and his peers can minimize the damage to a pitcher's arm by examining his delivery (measuring elbow angle and shoulder and elbow force).

The one thing Fleisig could not explain to me, however, was why teams didn't spend more time trying to account for disparate recovery times. "That's a good question," he said. "People naturally vary in how quickly they tear things and how quickly they recover. By trial and error, some are more suited to being a relief pitcher and some more suited to being a starting pitcher. If you're thinking about the difference between three-, four- and five-day rotation time, I think different pitchers would be able to handle different things. I'd think it would be worth it to the team to find out how to optimize that."

So do teams ask him how to optimize that?

"No," Fleisig said. "Teams send pitchers here and the purpose of the evaluation is: Is he doing something that's going to lead to injury. We look for a red flag. No one comes to me and asks how often a guy can pitch. They don't even ask me whether this guy should be a starter or a reliever."

Then where might they go to for that information?

Fleisig paused. "What I do is a mechanical thing. Maybe if you took it together with a medical and statistical evaluation it would work."

Okay, so perhaps it's the numbers that tell a cautionary story. So next I called Will Carroll, guru of Baseball Prospectus. Carroll knows more about baseball than most people know about, well, anything. Surely this idea had been tried and dumped for some reason, right?

"Nope. It's a great idea and there's no good reason why they haven't tried it, other than baseball tends to move at a glacial pace," he said. "Some teams have done four-man rotations over a short period of time but no one will commit to it. There's no team where a GM felt comfortable enough to take that risk."

This isn't to say there's not a precedent for it -- as Carroll said with a laugh, "the precedent is pretty much everything before 1968." Back then, every team used a four-man rotation. It was only when the Dodgers went to a five-man rotation --because they had the pitchers for it, not out of injury concerns -- that other teams copied them.

Similarly, the numbers don't necessarily suggest that pitching more often leads to either injury or decreased effectiveness (again, it appears to be the number of pitches that is more relevant). I'd break down all the data for you here, but you're better off just going over to Baseball Prospectus, where they've sliced and diced the historical data various ways (a good starting place is here).

On the site, you'll also find a 2006 article from Carroll suggesting a reasonable, gradated approach he calls it "progressive" -- to determine a pitcher's natural limits. To read it is to say, "Of course!" So, I asked Carroll, how did teams respond when that article came out?

"A lot of them said, 'Interesting idea.'" He paused. "And it ended there."

When I mentioned the Giants, Carroll brightened up. "They've got the perfect scenario for it, but I don't think it's even crossed [GM Brian] Sabean's mind. If there's a team to try it, it's the Giants with Lincecum. Think back to the start of the season. You had four starters and then [Jonathan] Sanchez. You could have swapped him out when needed and gone with four. He's pitching better now, but they could still implement it at this point in the season. You'd just need to use pitch counts."

And what do baseball people think? I tried to reach Sabean but couldn't get him (and understandably so, as it was short notice and he has plenty else to focus on right now). However, I was able to reach Mike Reinold, assistant athletic trainer for the Red Sox. Reinold is the one of the top pitching specialists in the league and the man largely responsible for Jonathan Papelbon's innovative shoulder regimen (for a good story on it, go here). I unspooled my theory, then asked Reinold to tell me where I was off-base.

"Actually, it's a great thought process and I would agree with you," he said. "Every player is probably unique and identifying that is possible and probably would help." He paused. "I find that idea interesting."

As for why it hasn't happened, Reinold didn't want to guess, though he did suggest that if something like this did happen, it might not be entirely visible at first (teams being understandably cautious with their proprietary information.)

That left me still wondering about the rationale. I suppose one argument would be routine -- that pitchers are creatures of habit and they might not feel comfortable with a varying schedule. Then again, for $5 million, or whatever they're being paid, they could probably make that adjustment (they do it in the playoffs, right?). Surely, the main issue can't be that teams are just resistant to change? Can it?

After all, the Phillies recently deployed Jamie Moyer and Pedro Martinez as essentially co-starters (with success). Teams use closers-by-committee all the time. In the last few years, a handful of teams have gone to six-man rotations for short periods of time. Not to mention that teams turn pitchers into hitters (like Rick Ankiel) and hitters into pitchers (like Trevor Hoffman, who was drafted as a shortstop in 1989). They turn starters into closers (John Smoltz) and closers into starters (Derek Lowe). They build whole franchises around revolutionary concepts (like Moneyball) and spend hundreds of millions for big-name players, sometimes just because they can (no, I'm not talking about the Pirates).

So why not challenge another convention? Even if all you gain is three wins a season, that could be the difference between whether a team plays in October or goes home.

In fact, three wins is exactly what separates the Giants and the postseason right now. Just saying.

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