The Colorado Rockies recently demoted Jeremy Guthrie from the starting rotation to the bullpen, which wasn't an unusual move, given Guthrie's 7.02 ERA at the time. The Rockies elected to replace Guthrie in the rotation with no one, which was more of an unusual move.
Jim Tracy, of all people, announced a plan to use a four-man rotation, with a rough 75-pitch limit. It was a daring maneuver, and the early results have been poor, with the Rockies losing twice. Josh Outman retired 13 batters before getting pulled, and Alex White retired 11 batters before getting pulled. Of course, the Rockies have lost 12 of 13 games, so it's not like losing is a sudden, recent phenomenon. They made a crazy change in large part because of the losing.
Anyway, we'll see how long the Rockies' rotation experiment lasts. In the meantime, at FanGraphs, Dave Cameron thinks about how things could be made even crazier. He begins:
Yesterday, we talked about the four man rotation experiment that the Rockies are currently trying out, and while I expressed some skepticism that it is going to work in their specific situation, I do applaud the effort to try something new. What we know about the relative of performance of starters and relievers suggests that teams could theoretically get better run prevention by getting more innings to their relievers, or at least pitchers working in a role that looks something like a reliever.
It’s not a plan without costs, but it is also a plan that I think could allow a team to improve their run prevention simply through better controlling usage patterns, and would come with the side benefit of allowing them to spend more money on position players rather than pursuing highly coveted pitchers (who would have no interest in pitching for your team anyway). Is anyone crazy enough to try it? Probably not, especially given how well pitchers are doing under the current system. We might need to see a shift back towards expanding offensive prowess before anyone tries something this different, as the “don’t fix what isn’t broken” mindset has a powerful hold. However, the Rockies abandonment of the five man rotation shows that MLB teams are thinking about new ways in which to use their pitchers, and perhaps we’ll see a team try some variation of this before we die.
In the middle are several words, proposing a plan and highlighting its costs and benefits. This is basically just a thought experiment. No team in the near or even reasonably distant future is going to start doing what Cameron suggests a team could do. But this is Thought Experiment Thursday, after all. I didn't make that up. How better to honor the day than by honoring the day very literally?