I imagine the low differential might make a difference as his fastball velocity declines .
His fastball - change differential has also declined over time ( http://www.fangraphs.com/blogs/zack-greinke-is-pulling-a-felix/ ) as the usage of his change has increased .
I imagine the low differential might make a difference as his fastball velocity declines , but his fastball - change differential has also declined over time ( http://www.fangraphs.com/blogs/zack-greinke-is-pulling-a-felix/ ) as the usage of his change has increased .