Raise the turn or call down?

[CostaRicaBill]

Party Poker 3/6 Hold'em (8 handed) converter (http://www.selachian.com/tools/bisonconverter/hhconverter.cgi)

I need help with situations where i flop top pair, bet out on the flop, but then am bet into on the turn with players still to act behind me. Do I need to raise to knock them out even though I might be behind the turn bettor? Or would calling down be a better plan? The hand below is the closest example I can find at the moment.

Preflop: Hero is MP1 with A/images/graemlins/diamond.gif, 9/images/graemlins/diamond.gif.
UTG calls, UTG+1 calls, Hero calls, <font color="666666">3 folds</font>, SB completes, BB checks.

Flop: (5 SB) A/images/graemlins/spade.gif, 4/images/graemlins/heart.gif, 5/images/graemlins/diamond.gif <font color="blue">(5 players)</font>
SB checks, BB checks, UTG checks, UTG+1 checks, <font color="CC3333">Hero bets</font>, SB calls, BB folds, UTG calls, UTG+1 calls.

Turn: (4.50 BB) 6/images/graemlins/heart.gif <font color="blue">(4 players)</font>
SB checks, <font color="CC3333">UTG bets</font>, UTG+1 calls, <font color="CC3333">Hero raises</font>, SB folds, UTG calls, UTG+1 calls.

Is this raise appropriate here? Say I had AQo instead of A9s, would it then be a standard raise?

River: (10.50 BB) 8/images/graemlins/diamond.gif <font color="blue">(3 players)</font>
UTG checks, UTG+1 checks, Hero checks.

Final Pot: 10.50 BB
<font color="green">Main Pot: 10.50 BB, between UTG+1, Hero and UTG.</font>

[spamuell]

I've been making this raise a lot on the turn recently thinking that someone just picked up a draw and I'm raising for value. And every time I've just been shown that someone has picked up two pair. So I don't know, maybe.

Given that you opted for the turn raise, it seems consistent to bet the river.

[CostaRicaBill]

Yeah, at 3/6 when I get bet into on the turn after a seemingly non-threatening card hits, it usually means 2 pair.

But my question is, if I have like 3 people still to act behind me, do I still make the raise to knock them out and increase my chances of winning the pot even though I'm pretty sure I'm behind the turn bettor?

[Evan]

I think you have to raise. Anything that's beating you is probably going to check-raise since you showed aggressionon the flop. Most likely he has A3 or A7 or some kind of heart draw.

[spamuell]

[ QUOTE ]
But my question is, if I have like 3 people still to act behind me, do I still make the raise to knock them out and increase my chances of winning the pot even though I'm pretty sure I'm behind the turn bettor?

[/ QUOTE ]

I suppose it depends how sure you are. If you know you're behind to two pair, you should call. If you know you're ahead, you should raise (of course). At some stage of sureness in between (OK, let's call it a "fulcrum", bring back memories of great threads) is the point where raising becomes better than calling.

The best way I can think of working out this point is through doing a bayesian analysis of the likely hands he will bet into you with on the turn together with the probability that he holds each of those hands (e.g. A6s might be more likely than 73o because he's more likely to play it, or less likely because he'd bet two pair but check-raise a set) and then we can work it out from there. I'm much too tired to do that at the moment.