I have no idea, but I did recently find a (free) podcast on the BA site talking about the NL Central Top 10's. Basically, they said that there's no system that particularly stands out above the others. They seem to be high on one or two guys from the Pirates, Cubs, and Reds, and reiterated that Houston has a drop-off after the top 3 of Castro, Lyles, and Mier. However they said they'd take any of those 3 over the Cards' #1 guy (Shelby Miller I think).