There is probably a better way of doing this then just looking at their total career numbers with and without, but whether you look at career WAR or just a few seasons before and then during Cooper's tutelage, the results stand out.

I'll give you a few examples:

* According to rWAR, Garland had three very good seasons with Coop, and nothing coming close since.
* Javy Vazquez's 2007 was better than his two great seasons in the National League, believe it or not, he posted 5.9 WAR on the Southside that year, compared to 5.4 in 2003 and 5.2 last season with Atlanta.
* Freddy Garcia's best season was his rookie year when he racked up 5 WAR, but he still averaged .1 WAR better per season while with the Sox, including 4 and 3.4 WAR seasons in '05-'06.
* Bartolo Colon's best season was in 2003 (4.7 WAR), better than his Cy Young season in 2005 and any season he had while with Cleveland back in his heyday. Yeah, it's just one good season (and part of one we'd like to forget), but it's notable that so many of these pitchers enjoyed their best seasons under Coop.