He says (scroll down):
“Thoughts: Barry Bonds is 42 years old. He’s beat up. He’s disliked. He’s got intense pressures weighing on him every day. If most of us think he was taking steroids and other performance enhancing drugs before, I’d say most of us also think he probably isn’t taking the stuff now. There’s too much heat now.
And yet Barry Bonds, RIGHT NOW, is having one of the greatest offensive seasons in baseball history. It’s amazing. He’s been so good the last few years, so unbelievably good (using all meanings of the word “unbelievably”), he has set such absurd standards, that I’ve actually read stories saying that Bonds is having some sort of off-year.”
He then goes on to prove it. Read the whole thing. Then read what he has to say about Griffy. While you’re at it, read his post on Dotel and Beltre. There’s nobody out there who writes about baseball better than Posnanski these days.