First, let's be clear. Gregg and Capps were two of the worst closers in baseball not named "Hanrahan" in 2009. Among relievers with at least 15 saves last year:
- Capps was 2nd worst (Brad Lidge) in win probability added at -2.83. That means the team would have won 2.83 more games if they had gotten an average performance in Capps' innings. Gregg was 3rd worst at -1.04. In fact, Capps was 2nd worst of any reliever in baseball in this crucial stat. (Kyle Farnsworth was 3rd at -2.15, followed by Luis Ayala at -2.13, if you're interested.)
- Capps was worst in the league in opposing hitters OPS+ at 146. Gregg was 6th worst at 97.
- Capps was 2nd worst (Brad Lidge) in ERA+ at 71, while Gregg was 4th worst at 95.
- Capps was 2nd worst in the percent of inherited runners allowed to score: 57%. Gregg was tied for 13th best at 18%.
The key question is which of these one-year contract recipients (read: the age difference doesn't really matter) can we expect to be better in 2010. Let's start by looking at the projection systems. These aren't gospel, but they have a reasonable track record, and if one player is clearly better than the other, there's usually a consensus:
CHONEOther than ZIPs, they're pretty close across the board. Marcel likes Gregg better, ZIPs and PECOTA likes Capps, and CHONE and Bill James expect Capps to have a lower ERA in fewer innings, which is close to a wash. But if all you had was these numbers, you'd give a slight edge to Capps.
Gregg (3.90 ERA, 67 IP)
Capps (3.63, 57)
Gregg (4.09, 66)
Capps (4.19, 58)
Gregg (3.93, 65)
Capps (3.58, 65)
Gregg (3.60, 65)
Capps (3.47, 57)
Gregg (4.50, 70)
Capps (3.88, 65)
Still, I like Gregg better for a few reasons. First, there's health. Capps missed a bunch of time at the end of 2008 with throwing shoulder issues, which would be a flag in any case, but considering his heavy workload in '07 and '08, plus his terrible '09, the flags are even bigger and redder for me. Gregg's had a balky knee, but there's nothing worse for a pitcher than an achy shoulder.
Second, Capps is far more hittable. His career strikeout rate is 18.6%, compared to 23.8% in 2009 and 21.3% career for Gregg. No, Ks aren't everything, but over the long haul I have a lot more confidence in guys who can miss bats than guys who can't.
Third, there are the splits. Gregg has a slight lefty-righty split, but nothing unusual. Capps on the other hand gets massacred by lefties. Opposing managers seem to have figured this out, as 2009 was the first season of his career that he saw more lefties than righties. And I vaguely recall some pretty good left-handed hitters in the NL East.
Finally, Gregg's just had success over a longer period of time. Capps was outstanding for two years and terrible for one. Until last year, Gregg had been a pretty useful guy for basically five seasons.
Don't get me wrong--I applauded the Capps signing. Given then need and the cost, I thought it was a reasonable move. But I still think the Nationals are 1-2 solid relievers from having a decently below-average group, and I think they need to add at least one more reliable bullpen arm. Gregg would have been as solid a choice as anyone left out there now.