I only count 3, Scherzer, Price and Hamels. Before last year, Lester had a 3.75 era and a 4.82 before that. An ace doesn't put up those numbers especially the 4.82. As for Shields, he's an innings eater. Zimmerman is close to an ace but I wouldn't label him that yet, I want to see another great year. Fister is a number 3, Porcello is a 4 at best. Samardija (sp?) is a good number 2 option. The above poster mentioned Cueto who is a boderline ace only because he has problems with injuries so that hurts him. Latos is a great number 2 but hes not an ace. The label Ace gets thrown around a lot but there is only like 10 Aces in the game.