You guys can make all the excuses you want as to WHY he's leading the league in tackles, but the fact is if he wasn't as good as he is he wouldn't be making all those tackles. He could be on the field for 50 out of 60 minutes and still not get that many tackles if he wasn't a good linebacker.
On top of that, the Niners have been reviewing their film and they say the league is not crediting Willis with over 20 tackles he made. They have been submitting the film to the league to correct their stats, but they haven't done it yet. So let's face it, he's leading the league in tackles while not being credited with a bunch of tackles he made.. He's a beast. Period.