Clack wrote:
Third, I think people underestimate the size of the hole created by Valverde's loss. After you factor in the cost of replacing him, you may not end up gaining much from the trade. A significant reason (IMO) for the improvement between 07 and 08 is the difference between the terrible closer situation for the Astros in 07 vs. the more stable closer situation provided by Valverde in 08.

Interesting point. Looking back at what Arizona got in return for Valverde, Qualls looked good and I think he was missed this year on the Astros roster, but Burke was a non-factor for the Diamonbacks and Juan Gutierrez is yet to be heard from. A 90 win team in 2007, they won only 82 games this season.