I'll give the whole stats thing a go.
Since New Zealand toured in May last year, accepted by everyone as the time when Anderson's bowling improved massively, he's taken 69 wickets in 18 tests @
28.65.
Sounds reasonable, right?
Now, looking closer at the games he's played in that time, the aggregate bowling average is in fact
38.45. So on the pitches Jimmy's been playing on for the past year, the average player is taking his wickets at 38. These are some horrendous bowling conditions. Even in the 2000s, widely accepted as a period of unspeakably flat pitches, the aggregate average is
33. Suddenly, 28 looks bloody impressive.
Sorry for the mathematical burst, but hey, I'm a nerd. Contrary to a lot of people here, I think stats- unlike raw numbers- can tell you a lot if you use them properly.