Do I bet this river?

[FoxwoodsFiend]

I suppose the logic of betting the pot stands if everyone at the table is completely oblivious to what's going on. The fact is there's near-perfect transparency, we both know what the other one has (except i have three possibilities) and yes, he does know I'm capable of making a laydown there with KK. If he knows I'm putting him on a set then it's a pretty easy check-raise bluff opportunity and if he moved all in I would indeed have mucked. Thus, given the possibility of him folding if I bet heavy as his read of my KK would be confirmed and the fact that he could easily push me off KK here, I don't understand how people are still advocating such large bets. ML4L is right on this one, and I suppose that at a low enough level of play it always makes sense to get your chips in here but villain and I are both good enough that you just can't say "I'm willing to put 9k in to this pot and hope that all he has is 99 or 22 and if I go broke, well-I couldn't have done anything about it. I mean, full house versus quads never happens, right?"