They've been doing rankings position-by-position each week this offseason, and this week's issue ranked starting pitchers.
Here's the article; among Cub starters, Carlos Zambrano ranked ninth and Mark Prior 18th.
Here's what they wrote about Prior:
Health, of course, is the key issue -- and in addition, there's the just-revealed information about Prior voiding the final year of his deal and becoming arbitration-eligible, which you can discuss in the diary on the right sidebar.
Finally, Barry Zito is ranked 15th. For anyone who doesn't think acquiring Zito could make the Cubs an instant winner -- I'd say having three of the top eighteen starters in the majors would make any team a formidable rotation. For comparison's sake, the White Sox, who won the World Series in large part due to the strength of their rotation, have their top three (Buehrle, Contreras, Garland) ranking 13th, 15th and 20th. Note that Greg Maddux even sneaks into the top 50 at 49th; that's roughly comparable to the White Sox' Freddy Garcia ranking 44th.
The article goes on to say something that we've been talking about here for quite some time, about Kerry Wood: