Agreed on Greinke.
I agree on Santana, that guy was a monster. not so much anymore.
Beckett of old? yes. Current Beckett? not so much
as you said in the duplicate thread(or other one whatever)
this list should not be necessarily the "ace" of a certain team but of the best pitchers...regardless of where they would be in the rotation on any other team....
although,atleast to me, when i look at the list of really "elite"(although this is a very,very,very,very, subjective categorization) pitchers in comparison to aces...its pretty much identical
no real difference except for a few maybe outliers like cole hamels(but i dont think hes really an ace either...)