Not the most exciting spot in the world but I'm brushing up on my OOP play, and this is a very common situation. Super early in a $20 MTT online.

PokerStars, $18.20 + $1.80 - Hold'em No Limit - 20/40 (5 ante) - 7 players
Hand delivered by Pokeit

UTG: 5,160 (129 bb)
MP: 9,056 (226 bb)
MP+1: 5,408 (135 bb)
CO (Hero): 4,223 (106 bb)
BU: 5,315 (133 bb)
SB: 5,340 (134 bb)
BB: 5,169 (129 bb)

Pre-Flop: (95) Hero is CO with 8 A
3 players fold, Hero raises to 108, BTN calls 108, 2 players fold

Flop: (311) 3 8 9 (2 players)
Hero bets 271, BTN calls 271

Turn: (853) K (2 players)
Hero checks, BTN bets 120, Hero calls 120

River: (1,093) 3 (2 players)
Hero checks, BTN bets 280, CO (Hero) folds

Wondering about going for a x/r on the flop but given how draw-heavy it is, I opted for a large CB. Did not like that turn card.

Why so big on the flop? Smaller on the flop, larger on the turn = more profit. As played, it looks OK from there.

The flop isn't particularly good for my range and there are A LOT of cards I don't want to see on the turn. I'm also OOP. I think betting small on that flop is a mistake.

If the flop isn't particularly good for your range, why would you put in a massive bet??

It's quite a common misconception to want to bet large on this kind of draw-heavy board.

You want to play defence when out of position, and even more cautiously when deep on such a dynamic texture. Your equity is much less stable, and once you start checking later on once the board complicated, BTN can start to put you in some nasty spots. This is exactly what happened in the hand, and even if you had a less vulnerable hand like AA, it would run into similar problems given how dynamic the boad is.

It's understandable to want to protect but this is an illusion since IP will never fold a straight or flush draw, so you are not actually protecting anything.

I'm curious as to whether the A8s flop bets in that solver are mostly Ac8c (with the backdoor flush draw) or split more evenly-- or even less frequent with the club backdoor.

Yeah more with the clubs for sure although the others are decent frequency too. For the unpaired hands it's clubs and hearts only

Generally speaking, when you don't have the range advantage you should be betting less frequently but on the larger side when you do bet. So I'm surprised at those solver results.

I don't see the point in a small bet at all. It allows villain to continue with so much of his range and then put me in a nasty spot on later streets. The benefit of the larger bet when OOP is that it more clearly defines villain's range, making later streets easier to play. He's obviously not folding his good draws but he can have weaker overcard/draw combos that he would fold to the larger bet.

Maybe the point is just to charge the smaller pairs and 2 overcard combos that are behind in equity? It feels wrong to check when our hand needs so much protection.

When I first learned poker from Harrington on Hold'em, he said that the right way to play against draws is to charge just enough so that the opponent is making a mistake by calling. With 4:1 on a naked FD, if you're betting half, you're printing money. If you bet too much, your opponents might actually find folds.

I think most people explained why you should go smaller on the flop already, but if you're going to take something away from this hand, it should be that you're thinking about the spot a bit backwards. Hopefully you can see why going forward... it's a super important point to understand imho.

I went over some stuff recently and realized my OOP thinking was all out of whack. Solvers rarely use large bet sizes OOP because equities run so much closer together and it's hard to have a clear nuts advantage.

Isn't the K turn a good double-barrel card for our range?

I would use that small river sizing V used quite often as an exploit. It b-c at least a lil with like TT, JJ etc because its just begging OOP to take the pot away with a xr (id basically always have exactly what the bet implies--something valuey but foldable vs aggression) so Id expect quite a few xr bluffs there. At least, I would xr there quite a bit--I think when they go so small they write a check that'll bounce (wont b-c often enough)

I would check with A8s and no BDFD but I am not a Solver... Here I would bet but small (like 20% to 25% pot size) as a more or less blocking bet. If the turn is a club/8/A I bet again like 50% pot. River would be tough if we don't hit the flush or improve. I probably check/call in case they decide to buff with flush draw. Though if a an overcard or two has hit it could be a fold on the river.

If we had bet small on the flop and got called when this turn comes I would likely check/fold.

I like the cbet sizing but not with an 8. Gotta be stronger and probably underbluffed as people will get stickier on turns and rivers when they do find a continue facing nonsmall as opposed to how they behave when the continue vs nonlarge sizing

High frequency check spot on the flop, while we do have an equity advantage it's not particularly huge, and our second pair hands with a club just do not want to bet very often. When we bet it's almost always small.

As played on turn I like your instinct to downbet, but probably not that small. Because you went bigger on flop, your overall range should be stronger and a lot of your range should be hands that have a fair amount of equity, like good top pair+ and some flush draws. I'd go something more like 33-50% if I bet.

I think our specific hand mostly wants to check turn, but I can see this hand moving into bluffing territory with the idea that we're trying to get a 9 or hands with equity (like JT/QT) to fold, which they should do at some frequency. When we go this small, we can bet a lot more, but now a lot of the QT/JT-type hands just continue pure, all of the 9x continues pure, so the bet really doesn't accomplish much other than maybe keep some smaller pairs in (which may in practice start folding if they don't have a heart anyway).

River sizing by villain is not a thing in theory at all, probably should be going something like 75%. I think our hand probably just pure calls because we do beat those bluffs that stuck around. Could argue for check raising river very occasionally since we block boats and we would absolutely have some hands like flushes and boats that could conceivably play this way, but I think our sub-optimal sizing on turn probably makes that difficult.

A8cc pretty much checks pure, pretty much any of your suited 8cxc wants to check. You have lots of equity, but you're in jail if you get raised and if villain polarizes on turn you almost always have to fold unimproved. Your A8 without backdoors are fine betting, in part because you're not blocking the backdoor Acxc hands that almost always just call. And you do want to have some 8x to allow you to have trips sometimes.

As your 8 gets worse, you pretty much start checking pure.

What's interesting is that for your 3x, it's actually the opposite. In those situations, it's your A3cc/Q3cc that want to bet, mostly because they fold out some pairs (like 44/55) as well as some backdoors with decent equity, like some offsuit broadways or backdoor Qcxc or Kcxc.

I don't work with solvers directly, but I would check the flop.

River fold seems really bad to 1/4 pot bet. Villain's turn bet was even smaller. He can have a busted flush draw or a worse 8, etc.

Preflop
Standard open.

Flop
As others have said, this is a check or bet small spot. Yes your hand is vulnerable, but we dont make massive bets in poker, if they are mainly for protection. We also C-bet far less, when someone call us in position, than if we get called by big blind. This is because, the player calling in position is supposed to have a stronger range, and obviously they have position. So when we get this in position call, its important to get rid of the idea, that the pot "belongs to us", just because we raised preflop. When we hit a middling pair like this, our goal should be to get to a cheap showdown and perhaps catch some bluffs and/or improve, but we should also be ready to sometimes let it go on a later street, if we face heavy pressure and/or a bad runout.

Turn
Clearly a check, and when he bet this small, you cant fold.

River
Even though he size up compared to the turn, its still really small. I just dont see a flush bet for this sizing, so he is kind of saying, he has a maybe a weak K or a 9 and wants thin value? There are busted draws, so I might get curious and stick in a call here. You only need to win this 1:5 times to make a profit, and you get information as well.