Diamond's 'Curve Ball'

[E. Andrew]

I apologize for starting a thread for such a narrow topic, but am I missing something here? I was browsing through MLB Leader Boards, and noticed that Diamond's curve ball is the only one in the league with a 'positive' vertical movement. That is, it resists gravity, necessarily indicating that it has backspin. Regardless of whether or not PITCHf/x is categorizing his pitches correctly, his pitches do not include a breaking-ball. He is throwing this 'curve' 25% of the time, and it has worsened in each of the past three years. Thoughts? Correct me if I'm wrong...

[Willihammer]

Yeah his curveball is awful.

 

He got by last year on impeccable fastball and changeup command. Like Pavano in 2010. But when you lack a real third offering, you cannot afford to lose even a hair of command or you'll get what we're getting now. I don't even see a bullpen role for him atm, his stuff is just too poundable.

[Nick Nelson]

Parker had some stats on the efficacy of Diamond's curve this year and they were brutal. The deterioration of that pitch, which has been a go-to for him in the past, has been one of the biggest contributors to his downfall.