Ran into this situation last night in 1/2 no limit and trying to figure out the best line:

Unraised multiway pot with 6 callers:

Hero has 99

Flop: 492

Villain directly to Hero's right makes a pot sized bet of $15.

Hero ??

What is the best line here? I can think of 3 options:

1. Make a min raise. If villain comes over the top, fold.
2. Call. Since there are 7 players in the pot (6 plus the bb), we can induce more callers and possibly win a monster pot if we hit. Fold the turn if it does not help us, or fold if the pot is reraised on flop.
3. Fold the hand, since it is a multiway pot and pretty likely villain has a flush.

Your thoughts?

What to do depends on stack sizes and villains.
Reads?

Villain is solid tight aggro. Effective stack sizes are 100 bb.

villain pretty likely does not have a flush
choosing any line which involves you folding on the flop is absurd.

you should probably make it like 40-50 and never fold.
villain can have lower sets, decent flush draws, some other pocket pair, whatever. sets are really hard to make... don't try to fold them.

Given that it is a limped pot and you flopped top set, drastically diminishing the possibility that V is betting TP, it is likely that they are betting a made flush or on the come with AsXx. 22-88 are also reasonably within V's range.

Raising to any significant amount should fold out all of V's range except for sets, made flushes and AsXx, which likely has a gutter too.

With a minimum of 30% equity against the top of V's range and the potential to have him coolered w/ set vs. set, this is a clear raise for value, and although its uncomfortable you should GII to a reraise.

Make it 55 and shove any non-spade turn that does not pair the board. Check behind and reeval riv otherwise.

What position are you in?..

Why was it an unraised pot with 99?

Folding the flop is awful. I'm not sure that a raise gets called by much that we beat though. If it was a raised pot and V's could have overpairs with NFDs it would be a different story.

I probably flat the flop, then re-raise most turns to get it in, depending on the stack sizes and number of players at that point.

I would flat the flop as well. I usually play this a bit more conservatively especially in a multiway pot. I'm assuming you were EP which is why you elected to limp with your 99? In LP, I open with that hand a lot and then hopefully see this flop HU. In that situation, I do think the best play would be to raise his flop bet and take a more aggressive line.