I think that's the case with most pitchers, the mental game. Last game BA and Rock were talking about the coaches reminding DL Hall to breathe when he is on the mound.
Depends on what you mean by really good. Abner had control problems. So did Freddy in the beginning. So does Sproat.
Sproat has a pretty good fastball and a very good slider. He had one good inning tonight, then completely lost the strike zone. I'm not saying he'll be good someday. But he might. They'll work with him.