Measures of Qualls-ity

Arizona has shipped Chad Qualls to the Rays, eliciting responses ranging from anger to mockery to happiness.

Qualls is having an off year, his worst showing of the past four campaigns. It’s just not as bad as his bloated ERA indicates. Using pitch-by-pitch linear weights to derive “ERA”, both rvERAe (based on batted ball types) and rvERAa (based on actual hits and outs) have jumped for Qualls in 2010. This is along with an apparent downward trend in both whiff and ground ball rates.

Not a stud, not a dud. You may even expect Qualls to regress towards his career/recent levels—improve, in other words.