Who Will Close For The Cubs?

With the departure of Kerry Wood, and the trade for Kevin Gregg, the Chicago Cubs now have two potential closers for 2009. I've seen speculation that Gregg will close, and I've seen speculation that Carlos Marmol will close. Strangely, everyone who writes about it seems quite sure of their opinion. I'd say that this one is very much up in the air. Before I did any research, I was assuming that it would be very clear that what the Cubs SHOULD do is make Marmol the closer. After looking at the numbers, it's not as clear cut as I expected. What it really comes down to is whether you think Kevin Gregg's weak 2008 numbers (K/9: 7.6, BB/9: 4.8) were simply a bad season, or a sign of declining skills. While it was his worst performance in the past five years, it wasn't quite far enough out of line to be sure that something was wrong. If he gets his K/9 up to the 8.0 to 8.5 range, while lowering his BB/9 to 3.0 or slightly above, then he's not much worse (if any) than Marmol, who strikes out a ton of batters, but has awful control (over 5.0 BB/9 for his career) and appears to be a really extreme flyball pitcher.