Over the course of a 162 game season, you have to be willing to lose a game or two, losing the battle to preserve your ability to win the war. You can't throw out your best every day. It's very likely that a substantial portion of those losses are going to come against the opposition's ace. When you write up the schedule, whenever you have your 5th facing their ace, you are going to chalk up a loss in that game. If you lose to Lincecum, so be it. But you really don't want to lose to the 5th starters of the world. You want to take advantage of every one of those opportunities.