I can't tell if this thread is debating what it means to be an ace or who the best/most reliable pitcher is. I hope it's the latter, because the former is pointless. As of right now, if all 5 starters were on enough rest and there was only one game left that mattered, Ted Lilly most consistently gives the team a chance to win, and I think Hill and Marquis are a tie for second. Zambrano easily has the highest ceiling on the staff, and in the three seasons prior to this one, he has easily been "ace" material, but he's been very bipolar this season, with plenty more games on the crappy end of the spectrum. To respond to the previous post asking about whether yesterday or tomorrow matters more, I think cubbiechris nailed it to say that it's always today that matters most, and Lilly is that guy on this team.