He was below average at best from 06-09. He's had a rather amazing resurgence, especially over the first 5-6 weeks of the season, but his production is starting to lag again. It's still a plus considering everything pointed to him being very bad this year and he's been a good starter for the first half.
Yeah, I'm not disagreeing. He definitely is on a sort of "tail spin" right now (like that graphic said: 5+ era in June, 4+ era in July) but he's one of the least of our worries right now. (When he's pitching we are 11-7)