Bourn’s arrival puts Luke Scott on the trade market. Both are left-handed hitters, so there’s no possibility of a platoon, with Hunter Pence rotating between center and right. The Astros probably wouldn’t want to jerk Pence around like that anyway. Scott has created 17.3 runs per 100 plate appearances in his 231-game major league career. Since he’s not guaranteed to maintain that rate going forward, let’s also be optimistic and project Bourn at 12.1 runs per 100 plate appearances -- the midpoint between the career averages of Juan Pierre (12.5) and Willy Taveras (11.7). At five runs per 100 plate appearances, the Astros would be giving up 25-30 runs next year with Bourn in center. They’ll make up a lot of it on defense, but for it to be a wash, they’d need Bourn to post a .340 OBP. Even if that happens, they’ve still opened up a big hole in the bullpen without upgrading elsewhere. They saved money by making the trade, but it’s going to go right to finding another closer. Chad Qualls works better as a No. 2 man in the pen, so the Astros could spend $10 million per year on Francisco Cordero or $5 million-$6 million on Todd Jones, Scott Linebrink or Octavio Dotel.

One more factor that doesn’t get weighed in nearly enough in these types of deals is draft picks. In dealing Lidge, the Astros cost themselves the potential for two early picks in 2009. And now if they replace him with Cordero or Linebrink, they’ll be forfeiting a pick next year. Their first-rounder is protected because of their lousy record last season, but second rounders are still important for a club with such a weak farm system. The Astros got less talent out of the 2007 draft than any team in baseball. They need to be hoarding draft picks, not wasting them.

What makes the deal such a winner for the Phillies is that Brett Myers is returning to the rotation. Sure, they could have done that without acquiring a closer, but they weren’t going to. Myers is a better addition to a group that also includes Cole Hamels, Jamie Moyer, Kyle Kendrick and Adam Eaton than any free agent starter would have been. Even with Aaron Rowand still likely to depart, the Phillies could afford to move Bourn because of Shane Victorino’s presence. They’ll play Victorino in center if Rowand exits and then go after an upgrade in right field. They’d prefer a right-handed hitter, so Jose Guillen would make a lot of sense, if they don’t mind signing a cheater. Unfortunately, most of the other options out there are lefties. The Phillies could settle for a platoon guy and use Jayson Werth versus southpaws, but with neither Werth nor Victorino known for their durability, they’d be leaving themselves susceptible to injury. It’d be a lot easier to go cheap in right field if they could sign Mike Lowell to play third. The money probably isn’t there, though.

One more thought: this makes GMs 2-for-2 this winter in getting significant deals done quietly. That Edgar Renteria and Lidge were moved weren’t surprises, but both trades came together quickly and were completed before the media got wind of them. As much fun as trade rumors are, it’s often the case that the ones we’re discussing are DOA.