Please do not think this way

Via Tyler Kepner's blog for the NY Times (hat tip to River Ave Blues):

Speaking of Chamberlain, here’s Johnny Damon’s take on his role. It seems to be the majority opinion of the veterans in the clubhouse: “Joba as a starter, he has a chance to help us out once every five days. Him coming in and bridging the gap to Mariano, he’s got a chance to do that three or four times during those five games."

Two things are egregiously wrong with this viewpoint.

1. The "chances" that Johnny talks about are not even remotely equal. The best starting pitchers in baseball game exert vastly more influence on the outcome of a game than the best relievers. In the last few years, only the top five to ten relievers are worth more than five additional wins above replacement over the course of the year. The top 30 starting pitchers are always worth more than that. The top five to ten starters are usually worth over seven wins above replacement. Joba has the ability to be a top five starting pitcher.
   
2. There is no way on God's green Earth that Joba can pitch out of the bullpen four times in five days with regularity. Hell, even pitching him out of the bullpen three times every five days is borderline reckless. As a reliever Joba will have an opportunity to make a difference in at most half of the Yankees' games, not the 60 to 80 percent that Johnny thinks it is.
   

Remember, the issue is not that Joba is guaranteed to be more valuable in the rotation, it's that he has the potential to be more valuable. No team in their right mind does not first try their stud, ace level, pitching prospect as a starter. If, after two or three years, he is unable to make that cut it in the rotation, then put him back in the bullpen.