He's a former starter moving into a closing gig. History tells me that makes for a great closer
The history that we remember
tells us that a starter moving into a closing gig will make a great closer.
I think we're far more likely to remember the success stories than the failures.
I"m guessing that the SP-to-closer success examples (Eckersley, Righetti, Isringhausen, Smoltz, Gagne..etc.) are far outnumbered by the cases that didn't work out.
After all, if going from being a SP to being a closer was really that easy, no MLB team would ever sign a closer as a FA, or trade for one...They'd just take one of their crappy starters, and make him a closer.