Will Matt Garza improve the 2011 Cubs?
The short answer to this question is, "Probably." You might also go with, "Jimbo Hendry better damn well hope so!" But it's not too hard to come up with a way to answer that question in a way that actually uses some statistics from 2010.
Let's assume, for the sake of convenience, that Matt Garza will start 32 games for the Cubs next season. It just so happens that there's a group of four pitchers who started exactly 32 games between them for the 2010 Cubs. They are: Ted Lilly, Casey Coleman, Thomas Diamond, and Jeff Samardzija.
Lilly pitched pretty well last season when he was healthy enough to take the mound. In fact, his strikeout and walk rates were pretty darn close to Garza's, although Lilly's home run rate was a bit higher than Garza's likely will be. Again, for the sake of convenience, let's call these 18 starts a wash.
In that case, one way to look at the deal is, Hendry has replaced 14 starts he got in 2010 from Casey Coleman, Thomas Diamond and Jeff Samardzija with 14 Matt Garza starts.
That's probably an upgrade, isn't it?
It's a pretty tricky business trying to guess how a starting rotation will fare from one year to the next. Carlos Silva was great in the first half last year; Carlos Zambrano was relegated to the bullpen for a ridiculously long amount of time; and even though they've shown the ability to succeed in recent seasons, it's still hard to know what to expect from relatively young guys like Randy Wells and Tom Gorzelanny going forward. But if you look at the deal as basically having gotten a full season of the 2010 version of Ted Lilly back for next year (about 10 years younger, with much more upside), I think the rotation looks much better than it would have without him.
The best rotations in baseball have been worth around 19-21 wins above replacement over the past several years. The 2010 Cubs were worth 15. Could Dempster, Garza, Zambrano, Wells, Gorzelanny and Silva put us toward the top of the NL in terms of starting rotation? I do believe so.
As for that godawful bullpen and meh-diocre offense...