In response to Jim putting some numbers to Jon Danks struggles last season, I went back and revisited something I had intended to publish but never got around to because of crashing browsers and generally laziness.
In addition to getting hit much harder as the game wore on, John Danks got the snot kicked out of him the second and third time he had to face a team within the season. Have a look at this troubling trend.
With the exception of his walk rate, every peripheral trended in the wrong direction as teams got to know him.
Danks obviously faced more teams that he had already seen as the season grew older, so you can argue correlation doesn't necessarily mean causation. But coupled with the in-game trends of the same nature, these stats don't paint a pretty picture for the future.