This past week Jim Tracy, Manager of the Colorado Rockies, announced his team would be switching to a four-man rotation. For non-fans, that means using four starting pitchers (the ball-throwing fellas) instead of five, which means fewer days off for the four starters. It was pretty much a desperation move; the team’s starting pitching, which has been decent for the last couple years, is last in the Majors in nearly every meaningful signifier, and they needed to do something radical. And this is a pretty radical thing to do—there hasn’t been a regular four-man rotation in baseball since the 1970s. Going to four pitchers is like if the Broncos went with just one linebacker or the Avalanche pulled its goalie for the whole third period. The historical trend has been to give starters less and less work. In the 1800s, guys with annoying Twitter accounts threw like 400 innings a year and had records of like 43-29. By the 1920s, guys were down to 300 innings a year, and by the 1970s, even pitching that much was rare. Pitchers were throwing harder and, perhaps coincidentally, were becoming more injury-prone, and for the last 40 years the five-man starting rotation has been pretty much taken for granted. Of course, that doesn’t mean it’s the right idea; like a lot of baseball’s conventions, everyone uses five starters because that’s what everyone does.
The move to a four-man rotation is something of a white whale for baseball analysts, a holy grail of a data sample that might never happen in the real world but which nonetheless represents some incredibly boner-inducing possibilities. It doesn’t hurt that both the stat nerds who roam message boards and grizzled, tobacco-chewing jocks agree that the four-man rotation is a good thing. Earl Weaver, the stoutest and coolest manager in MLB history, famously opined that it’s easier to find four good pitchers than five; the Orioles’ four-man rotation he managed in 1971 might be the best of all time. The statistical analysis community, the brightest of whom now work in front offices and help run your favorite baseball team, have been talking about four-men rotations for over 20 years. You can’t Google search the term without finding like 15 articles by the dudes at Baseball Prospectus.
Basically, the premise is this: Move the shittiest starting pitcher from the rotation to the bullpen and give your good pitchers more starts—about four extra a year each—and everything will improve. The bullpen gets a dude who used to be a starter—and is therefore decent—and his fellow relievers will be better-rested and therefore not suck. Statistical studies show that there’s not a ton of difference when pitchers going on three days’ rest instead of four, and there’s even incentive for those starters to pitch more: They’d compile gaudier stats and would make more money. Everyone wins!
Of course, it’s an idealized premise—no rotation ever stays healthy enough for each guy to throw 34 starts, never mind 38. It’s not hard to understand why: When you throw a leather rock 92 mph 100 times in one night, your arm will fall off. When you throw even faster every other day, which is what bullpen guys do, it will also fall off. It seems like if you’re a baseball team, you should try to do as much as possible to make sure your pitchers’ arms stay attached to their bodies, and stockpile extra pitchers in case said arms detach.
The Rockies play way above sea level, where balls carry. The high elevation and a broad outfield make Colorado baseball’s most consistently favorable hitting environment. Passable hitters churn out Hall-of-Fame stats, while pitchers flounder and sweat their way through games. Even by their standards though, this season’s crop of roundball hurlers has been lousy, and that lousiness combined with manager Tracy’s job security (he’s the only dude in baseball with a lifetime contract) has produced ideal conditions for this so-wacky-it-might-work measure.
Unfortunately for idealists and Rockies fans, it doesn’t look like this overhaul is going to work. In short, Colorado’s pitchers aren’t good enough, and the relievers have been overworked. Four-man rotations work in theory when teams have four good starting pitchers. If Colorado had four good starting pitchers, they probably wouldn’t be desperate enough to make a change like this in the first place.
It’ll be fun to see how long this sticks, or, at the very least, see what goes wrong and what can go right next time when another team inevitably tries it. It’s worth noting that it’ll probably just be Colorado again. In the years since five-man rotations have been a regular thing, the most recent experiment was when Colorado went to four starters in May of 2004. It lasted two go-rounds, and then they went back to five.