I thought this was interesting. Hand history from Live Low-Stakes NL that includes a large flop raise followed by dark check from villain.

Long story short:

Villain (loose, calling a lot, though not witnessed to be aggro) limps early, Hero raises w/ AA in HJ to $20. BB and Villain call.

Flop Kx 8d 6d

Hero bets $50, BB calls, Villain check-raises to $300, Hero calls, BB folds.

Villain dark-checks.

Here's full history:
http://forumserver.twoplustwo.com/17...-deep-1552659/

Curious to get people's opinions on what range they'd assign to villain with this behavior considering previous action. Here is what I said about it:

Should clarify above: when I say 'vulnerable hand' I mean a one-pair hand that could be pretty strong in context but is still just one pair. So even though AA or AK is pretty strong, it's still 'vulnerable'. That's how I think of it in my mind, which helps classify those hands as different from 2-pair and sets and stronger.

I've seen quite a few people check-raise with a draw, and I've also seen people check dark with a draw, though I'm not sure I've seen them used in combination.

Yeah, it's the combination that is interesting to me. I can't say I've seen it enough to have a strong opinion on it, but I've definitely seen it a few times over the years.

I think this could be a case where villain wants to semi bluff but maybe he doesnt want to empty the clip. A hand like 9d10d, or some kind of straight flush draw makes sense. The oversized semi bluff because he doesn't mind if hero folds. If a blank comes on turn, and he checks it looks pretty weak. The dark check eliminates that weakness if turn is a blank, and allows for a free river card if he misses turn, because no hero can bet into this line.

A set is never checking dark and KQdd isn't checking dark either. To an average player, KQdd is the nuts on this board and isn't a draw anymore. I think they would be more likely to shove turn with that hand rather than check dark.

In this example villain was new to poker, so his range is wide. But in general I think this would have to be a straight flush draw most of the time, if were up against a thinking player.

I disagree that it'll often be a draw. With a draw, most average players will want to see if they hit on the turn and won't want to miss value.

I don't think thinking players would do this; it'll just be very inexperienced players. I'd be surprised to see an experienced player take this line.

Didn't say this before, but the fact that the dark check here might be interpreted as weakness by an opponent, it's another reason why I believe it'll mostly be done with decent but vulnerable made hands.

Can you remember your suits? i think it would change his range a lot knowing if you blocked the nut flush?

I just looked at the original history; the guy did say he had Ad.

I don't think any bad or good player has a draw that they're willing to raise so large with and then give up on turn, so i was thinking some sort of draw + SDV like AKdd but thats obv impossible. (it would make sense for him to check/call top pair on blank turn and trap with nut flush if a diamond hits, even though a double check raise is pretty crazy).

Removing the nut flush possiblities i think the most likely hand is KQdd, KJdd, for the reason in the brackets ^^

I think the next most likely hand is 88. I highly doubt he has 2 pair here, if so he would be so bad that trying to break down his range is pointless as he would have no clear poker thought process.

I actually think Kxdd flops top pair + flush draw. Willing to pile in money on flop. Once called not loving his kicker. Turn dark check is I think is because he believes his hand is no good unless he hits his draw but to strong to turn into a bluff. If I had aces KJ+ I shove any non flush turn and feel confident about the spot.

bottom line dark checks are usually weak cool kid type of moves whens the last time you or anyone checked top set in the dark ,,,even if he does have a monster occasionally you should still play your hand strong, the guy seems a bit fishy at least over confident and stubborn signs of a calling station
...BTW villian likely has a pair with a flush draw checking dark shows his intention to call any turn ,,not necessarily river I say value bet away and make him show you,,

he's weak as **** put him all in

Lol there's already an entire thread on this..