According to Colorado Rockies manager Jim Tracy, his team has been relying on its bullpen too much. The team’s relief corps has logged the third most innings in the league over the course of the season, but for the last thirty days it’s tied with the Kansas City Royals atop the list of innings pitched.
In order to curb this trend, Tracy intends to limit his bullpen use going forward by … implementing a four man starting rotation that will be on a strict 75 pitches per start limit. In other words, he’s hoping to put less wear and tear on his relievers by asking his starters to throw fewer pitches between fewer days of rest.
Even if the Colorado Rockies had four excellent starters, which they don’t, there’s absolutely no reason to suggest that going with a smaller rotation will save bullpen arms. In fact, it would seem that such an action would have the exact opposite effect.
It means that one extra arm, Jeremy Guthrie in this case, can go to the bullpen, but if this is such a concern for the Rockies, why don’t they just forfeit a bench spot and call up an extra reliever as many teams will do from time to time?
Of course, this sort of thing was looked into a while ago by Tom Tango et al. in The Book, and they found the following:
Pitchers perform best with five days of rest, and worst with three days of rest. To manage our entire starting rotation effectively, four days of rest seems to be the optimal point. The current MLB pattern of scheduling the starting rotation works.
So, while it’s nice to see a manager attempt to do something unconventional that’s rooted in thinking outside the box, his justification seems so completely asinine as to make his efforts laughable. Making the move even more questionable is the fact that the Rockies don’t enjoy another off day until the All-Star Break.