I limp with QQT9sss OTB after 2 limpers (possible raise here, but I didn't--I think that's fairly borderline), SB completes.

Flop comes Q96 with diamond draw (I have spades). SB, who is imo one of the best PLO100 players (25/9 and major winner in my database) pots. All others fold. I have $194, SB has about the same.

I decide to try the call line here with position.

What does he have? Well, he can definitely have a lower set or top 2, but also a strong draw, of which there are a few. While a lot of the 100 players will tip their hands with a sub-pot bet on a draw, I don't think this guy will.

Turn makes diamonds with 5d. SB checks, and I pot. He CRs pot, and I fold.

Opinions?

Despite the result, I think I rather like my line here. It puts a lot of pressure on lower flushes. I don't think he can make the CR without the nut flush, really.

I did have some second thoughts after the hand about possibly taking the free card, but I really don't particularly care for that option the more I think about it, although I'm not completely sure how to approach the river if he check-calls. I'll probably need to fire again.

I'm also not sure about playing the nut flush the way he presumably did. The way I'm playing my hand doesn't look at all like a set imo, so I'm not sure that a check-call line isn't superior in the hope that I'll bluff a blank river (basically, it's at least unusual for me to have more than 4 outs here). Admittedly, it creates problems for him on paired boards.

looks pretty standard. Only way you are ahead is if he is bluffing the stiff ace of diamonds.

True, another very logical hand for him here is AA with Ad (with or without real flush on the turn).

The main reason I didn't raise is that there was at least one player who had limped early who will always re-raise AA, which of course he doesn't have to have. I think I can call a re-raise with this hand, but I don't really like it. If it had been even just QQJ9 with 3 to a suit to make the small difference of being placed a little better with straight draw, I probably would have...although I suppose the straight placement matters less in a HU raised pot with position.

Yeah, with 2 limpers I think it's fine to limp. I don't honestly think it's a huge decision either way and depends a bit on the table texture and how aggressive you are postflop (for instance, I think it's a better raise in a slightly tighter, more passive environment where you can win a lot of flops uncontested, and control your thinner draw/overpair-type matchups better with position against a single opponent who plays predictably).