When Francisco Cordero left the Brewers after the 2007, he was an elite reliever no matter where you looked in his stats.
His 44 saves, 2.98 ERA, 2.24 FIP, 2.82 xFIP, 2.12 tRA, and 2.70 True ERA all confirmed that Cordero was excellent in 2007.
These same stats all pointed to a 2008 downturn for Cordero. Some (34 saves; 3.33 ERA) didn't indicate the precipitous decline of others (3.77 FIP; 3.98 xFIP; 4.35 tRA; 4.56 True ERA), however. Whatever the case, Cordero seemed to be in decline.
The Reds closer got 39 saves with a 2.16 ERA in 2009, and his FIP rebounded to 3.10, so many assumed that he had returned to his 2007 dominance.
At best, the Cordero of 2009 was the same as the Cordero of 2008; he was probably worse.
Cordero's strikeout-to-walk rate is in tremendous decline. The 86/18 K/BB ratio of 2007 descended all the way to 58/30 in 2009—falling from 4.78 K/BB to 1.93 in just two years.
Batters made contact on 75.6 percent of their swings against the Reds closer in 2009, a career-worst for Cordero, and far above the stellar 64.5 percent of 2007. He also only got batters to chase 25.2 percent of his pitches outside the strike zone—his lowest rate since 2004.
Not only are batters making more contact against Cordero, they are making harder contact. His line drive rate, an excellent 17 percent in 2007, went up to 22.3 percent in 2008 and then 23.2 percent in 2009, well below average.
These problems for Cordero add up to a 4.86 True ERA. That's not only not closer-worthy; it's barely MLB-worthy. At his 2009 level of performance, Cordero isn't worth over $1 million per year. He makes almost $12 million per year.
That 2.16 ERA/4.86 True ERA difference (2.70 runs) was the highest of the 340 pitchers with at least 50 innings in 2009.
And it's not like Cordero has some specific ability to consistent beat the odds—his True ERA was lower than his actual one just two years ago.
So what made the difference, you ask?
Cordero's fly balls just happened to leave the park less often than usual last year; a 3.0 percent HR/FB ratio isn't sustainable by anyone, and Cordero's career rate (which is quite low anyway) is nearly double that.
His BABIP should've been in the .350 range given the high amount of line drives he allowed, but Cordero lucked out with a .301 mark. And no, he doesn't have some magical BABIP-suppressing ability; he should've had about a .290 BABIP in 2007, but actually had .341. His career mark of .315 is about where it should be.
As far as what could be causing the problem, it's worth noting that Cordero's slider and changeup came in at the fastest speeds of his career last year, while his fastball was actually a bit below Cordero's career average. It's possible that the lesser variation in speed is causing hitters to time the righty easier and get better swings.
This seems to apply to Cordero's changeup in particular. After two straight years of excellent results with the pitch, Cordero struggled badly with it in 2009.
With poor control (career walk rate of 4.19 BB/9), Cordero can't afford a decline in his stuff or strikeout ability, but that's what certainly seems to have happened.
If you're planning fantasy baseball in 2010, don't touch Cordero. If you're a Reds fan, brace yourself for those ninth innings. I doubt he'll be the luckiest pitcher in baseball for two straight years.