BB: 27 BB
Hero (SB): 39 BB

Hero posts SB 0.5 BB, BB posts BB 1 BB

Pre Flop: (pot: 1.5 BB) Hero has T9

Hero raises to 2 BB, BB calls 1 BB

Flop: (4 BB) 374
BB checks, Hero bets 1.5 BB, BB calls

Turn: (7 BB) 6
BB checks, Hero checks

River: (7 BB) Q
BB checks, Hero ?

I assume its a pretty good spot to bluff. What sizing would u use?

75% pot should be fine

Anyone else like a turn barrell here?

It's unfortunate if our GS gets folded out by a raise, but I think we fold out a lot of hands that beat us.

I don't like a turn barrel. As you said, we'll get check-raised relatively often on this turn card, forcing us to fold our gutshot equity.

You also have to consider how equity changes from turn to river. I mean, yes you can fold out low pairs with a second barrel, but with your overcards you also have outs versus all those pairs. By betting the turn you filter villain's low pairs out of his river starting range, thereby killing your pair outs, so that after double barreling you only rely on your gutshot outs (which as said are relatively often forced to fold vs a x/r). By checking the turn, you get to realize your equity better while still having pair outs on the river. I'd rather double barrel hands with 0 equity than this hand here.

Makes sense, again. ty!