Thursday, November 17, 2011

The Curious Case of Francisco Cordero

The Red Sox have been linked with Francisco Cordero.  Cordero has been a remarkably consistent closer since his elite 2007.  He's saved 34 games every single game since 2007.  His ERA has bounced around in those years, ranging from 2.16-3.84, but he's always held on to his closer job.  What's even more attractive is that he just posted one of the best seasons of his career in 2010, with a sparkling 2.45 ERA and 37 saves.

However, if we dig a bit deeper, things look much more bleak for Cordero.  Since his spectacular 2007 when he had a K/9 of over 12, his strikeout rate has declined every single year.  Despite his 2.45 ERA in 2010, his K rate was easily the lowest of his career (5.43 K/9) and was well below average for a reliever, let alone a solid closer.  He did lower his walk rate to the lowest it has been since 2007 (2.83 BB/9), but the strikeout rate screams that a disaster is looming.  How exactly did he manage to avoid disaster in 2010?  The lowered walk rate helped a lot, but the major contributor was his strand rate of 82%, well above league average of about 75%.  Looking at his expected fielding independent pitching (xFIP), Cordero has had an expected ERA of around 4.00 for the last three years.

In doing research for this, I found that Yankees reliever Tyler Clippard had an insane 95.6% of his baserunners left on base.  The worst with 60+ innings pitched?  Tim Wakefield at 59%.  Maybe he is worth another go around, as a bounceback in luckiness in runners stranded would make his ERA a lot more palatable.

But, if we dig even deeper, there are good signs for Cordero.  Despite the massive drop in his strike out rate, Cordero's swinging strike rate actually increased between 2009 and 2010.  Although it is well off his career high, his 10% swinging strike rate should lead to a K/9 of about 8.5, using the quick rule of thumb of swinging strike percentage - 1.5, which is very good.  If he can maintain his 2.84 BB/9 rate and his 50% ground ball rate, that would have led to a FIP of about 3.5 for 2011.  That isn't anything special, but it is solid.

All told, I'm not sure Cordero is a great fit for the Red Sox, despite his improved control and increased swinging strike rate in 2011.  Given his saves totals over the last four years and his ERA in 2011, he'll probably benefit from the "proven closer" reputation.  But, it is interesting to see how his statistics can be used to tell very different stories, as even the "Sabremetric" statistics point in different directions.  I could have written three very different posts using statistics.  Remember, as Mark Twain liked to say, there are lies, damned lies, and statistics.

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