Jose Quintana was never supposed to be this good.
Throwing 90-93 mph from the left side with an above-average curveball and an occasional changeup is a fine foundation for a regular starter, but probably not for a rotation leader. When Quintana started getting really good, he didn’t even have that arsenal fully developed.
Quintana’s stuff doesn’t leave him with a substantial margin for error, but his reputation is staked in the execution of these pitches. That reputation, and his results leading up to this season, makes him a hot commodity on the trade market, which starts pre-heating in June.