A few days ago in a game chat, Dexys observed that John Patterson seems to lose a lo after his 100th pitch. We don't chart pitches here at Nats Blog (we're obsessive, not insane), but we can calculate a pitcher's average RV per batter faced over different innings. Here's a chart of Patterson RV per batter for each of the innings in which he's pitched:
It definitely seems he can only go 6 innings, which is about 100 pitches, given that Patterson seems to throw a lot of pitches. The first and third innings are also interesting.