I tend to agree with Ennder. I'd call the guys he mentioned (Halladay, Sabathia, Hamels, Lincecum) HOF talents, but I don't see the point of saying there are only eight or so aces in baseball. I prefer "frontline starter," the term that's being thrown around in the trade rumors forum. It's all semantics anyway, so maybe the better question would be what are your favorite ways to evaluate a pitcher? Saying what he said--that guys who consistently keep their ERA under 4.00 and pitch 6-7 innings routinely--doesn't sound that impressive, but only 40 qualified starters had FIPs below 4.00 in 2008 (Haren was fourth incidentally), only 31 did in 2007, only 26 in 2006. In truth, that really does make you an elite starting pitcher.