Pirates ink Wilson

[wilkerson_rulz-06]

According to the canadian tv channel, Roger's Sportsnet, the Pittsburgh Pirates have signed SS JacK Wilson to a 3-year contract extension with options for 2009-2010

[KCGHOST]

This signing exemplifies why some teams just can't get it turned around. In 2001, 2002, 2003, and 2005 Wilson had an RCAA of -25 or worse. In 2004 he has a fluke season and racks up an RCAA of +6. Which season do they decide to use in determining his future value??

[Biggtone23]

I've seen it in a couple of threads but what exactly is RCAA?
I know its some type of sabermetric stat that is only understood by about 10% of the baseball fan population.