How many low scores constitutes poor form?

Kevin Pietersen is today blaming fatigue on his "poor form" in the latter part of the West Indies series, but I'm not sure why he feels the need to comment. He failed 3 times in the ODIs but that's no big deal - we can't expect him to score heavily every time he goes into bat. So Ricky Ponting has gone to number 1 in the ODI rankings - it's not the end of the world. With a good series v India he can easily get back to number 1 if that's what motivates him, although one hopes that England winning is more of an incentive.

Pietersen had a real average of 59.3 in the Test series - just because he didn't get a score in the ODIs shouldn't mean he's worried about his form. I hope he doesn't have it in his head that he's in bad form now - he isn't - he's just vulnerable early like he has been all of his career....