This isn't necessarily correct. For example say that 5% of his range is A8 and 95% is sets. If he folds A8 100%, a bet is still not the correct play.
If he only has 5% A8 and he has 95% sets, his range is constructed differently. He still needs to fold 37% of his range, but it's obviously much less likely. I should have clarified by posting that he only needs him to fold 37% of his weighted range, but I thought that was assumed when we talk about ranges. My point still stands, and it's more than fair for you (or anyone else) to say "he has a set way too often to do this, and he won't fold a set to a bluff on the river often enough for you to bluff." But that's very different than what you posted IMHO.
My problem with this play is related to that. The line villain took is very consistent with a set or 2 pair. Note that this villain plays 40% of hands and probably plays looser from the BB. This means that he can have more combos of 2 pair than one would expect. His line is not necessarily consistent with a top pair hand. He's going to c/r a higher percentage of his 2p+ hands than his 1 pair hands.
What I meant by my post earlier was that if you're going to make this play on the river, you need to have tpgk hands in his range. If villain's range is depolarized like this, calling the flop and turn is a mistake.
Fair enough, and I think that's a much better point for discussion than your original post that I took issue with (as I mentioned in my last post, I think "he pretty much always has a set here" is a reasonable assessment and helps clarify where someone's mistake might be). I disagree with a 35-40% range being able to reasonably have 2pr frequently on this board texture (he's the SB, not the BB), but I do agree that we should weight postflop actions more heavily than preflop. I also think that most players, once they check this river, are intending to call with sets but will be willing to fold lots of top pair hands as well as many of the 2pr hands that they'd checkraise on this flop. But I just don't see many combos of 2pr as being realistic from the small blind here.
All that said, it's pretty clear that the decision to bet the river as a bluff relies on an opponent playing top pair this way on the flop. All we have is the single data point on the KJ2 board, which is a strange way to play 22. I'm not sure what to do with that information - to me it makes it feel somewhat likely that we actually have the best hand on this flop, and once the river comes, in the moment I'd probably check, assuming that I'm actually going to win. But that's a LHE tendency for sure.
Regardless I think this is a pretty interesting hand to talk about and I'm happy to stir some shit up in discussion just to make sure it gets fair treatment.