For some reason, bullpen construction has become my pet topic lately. It just seems so mysterious. Some clubs (the Reds throughout the 1990s, the Braves and Padres currently) have no problem coming up with a great bullpen, while others (the 2006-07 Reds are the most painful example) can’t get anything to work.
In the next few months, I want to try to unravel some of this mystery – to figure out how good bullpens are assembled, and what makes a productive bullpen. In my actual job, I’ve had the opportunity to actually work on some of these issues (very long story), and I found that even elite relievers have an extremely short shelf life (see Dibble, Rob; Davis, Mark). This raises the question of whether it makes any sense to invest (at least in salary or contract years) money in the bullpen. I’d like to take a look at questions like that. So if anyone knows of good research or writing on that topic, please drop a link in the comment thread, or shoot me an email.