Originally Posted by Johnny Footstool
He needs a K/9 over 7 to even approach "ace" status.
I don't know if I agree. Certainly, someone with a K/9 over 7 is much more likely to be an ace than someone below that threshold, but guys like Steve Carlton, Juan Marichal, Jim Palmer and Don Sutton all reached the Hall of Fame, and arguably "ace" status, while rarely having a K/9 over 7. More recently, Tom Glavine is a pitcher that wasn't close to a K/9 of over 7 for his career, but still was an arguable ace for much of it.
I'd also add that I don't think Cueto is an "ace."