Can someone explain to me the live-theory of downbetting? Because unless I'm missing something, 90% of people seem to be using it incorrectly

Occasionally I'll watch a poker vlog, the algorithm has figured out I like poker. Almost all the the vloggers and smaller streams you see around love downbetting, can't get enough.

Even in the games I play, people do it. I assume because they watch vlogs...

So here's one of many many examples where I walk away thinking "What is that, that seems terrible"

$5/10
$30 open, call, guy 3 bets A2 from the SB to $125 both players call

A28 ($400)

A2 leads $90, he's gonna downbet to keep their ranges wide and invite them to call

They both do

A28J ($670)

A2 here always says like "Here I can size up" and goes $625, an absolute bomb.

And this is where I don't get it.
You've invited people to tag along with who knows what because you've purposely bet 20% on the flop, and then your bombing 93% into the abyss on turn?

In this hand the guy showed up with JJ and felts "Hero"

But that's always the pattern it seems, 18-25% and then 90%+ turn
It just seems so backwards in my brain. And when I'm playing at people do this, I absolutely call the flop I'll play your downbet games, knowing that if I spike something I'm most likely going to get 90% pot on the turn. This is based on most everyone who does this downbet follows it up with a huge bet (Which seems like it's the case very very often)

Same board and hand as above, lets say the turn is a 3. And the guy who flatted the initial open has 45dd and called the 3 bet closing action... seems reasonable that he'd call the $90 flop bet. The "Hero" bombs away on the 3 as well

I always feel like if I start a thread it's rambly

Point being it seems like the pattern of a "down bettor" is always 20% and then 80-90% and should be/is very exploitable. And yet I see it constantly

Hand strength changes a lot preflop to post flop, so when u have a strong hand pre u go big so that they don’t get to see 3 cards which will drastically change the landscape of the hand.

Once u get to the the flop tho the turn is only 1 card and won’t change stuff nearly as drastically so u can now bet smaller.

Now on the turn the theory is that villain would have raised flop with some nutted hands so on a brick turn they are “capped” and u are “uncapped” so now u have a license to bomb.

Guy gets coolered by a pair that turns a set, therefor betting small was a mistake?

Basically, you bet small on flop with medium strength hands to deny equity from weakish overcards and what not.
Villain is supposed to raise a fair amount versus this bet, so we put strong hands in that sizing aswell.

I’m not saying the small bet is the mistake, I’m asking I guess if the following BOMB bet is.
Goes back to the “What are you getting caller with”?
Can’t you accomplish the same with like 45-55%, without the risk of losing 90% and having to call off a few hundred more on a shove?

It appears the hero is giving an incorrect rationalization for what is generally a solver approved strategy (but might not be in this case given stacks and the flushdraw, IDK).

If you're doing it across all of your range or a balanced part of your range, obviously it's not just a slowplaying maneuver.

What you are asking is much too complex to be summarized in a forum post. You'd need an entire essay on the theoretical framework of the game. Best I can say is that it is a theoretically correct line and one that happens quite often. Of course people will misapply it a lot, just like they misapply range bets or any other line that is in fashion. As for your particular examples I'm not a huge fan of the line in hand 1 (top and bottom pair is one of the most frequent slowplays and generally not a hand you want to go mad with as it does not retain it's equity well when stacks go in) although it's by no means a great mistake. As for the other example with the 3 turn you correctly identify that it creates a disadvantageous nut asymmetry and in such cases solvers downsize and reduce betting frequency, as it does not make sense to pile money into a range that has nuts that hero does not.

It’s funny people 3 bet an when an overcast comes on the flop they downbet

Oftentimes this sort of line has a lot to do with range advantage.

For example, when a player opens for a raise and gets called by the big blind, they will have a massive range advantage on a lot of boards (because the BB is incentivized to call with a lot of junky hands since they're getting a good price and closing the action).

So it makes sense for preflop raiser to bet small on the flop to cheaply get BB to fold a lot of junky hands (when you're bluffing, when you're vulnerable to being drawn out by overcards, etc.) and also to get a little value from weakish hands BB has that will call a small bet like a gutshot, bottom pair, etc.

However, once BB calls flop and folds all their total junk, then the ranges on the turn are often closer between preflop raiser and BB, to where each player will win about 50% of the time. However, BB tends to have mostly medium strength hands, since they would often raise the flop with their strongest hands.

So then it oftentimes makes sense for preflop raiser to switch to a polarized strategy on the turn, where they bet big with their strongest hands plus some bluffs, and mostly check with their medium strength hands. This way they get max value with their strongest hands, and balance with bluffs.

A similar effect can happen in 3-bet pots, where 3 better often has large range advantage on flop but equities run closer together on turn.

It all goes back to game theory, solvers, toy games, etc. This stuff comes into play more as you get into higher stakes, and I wouldn't worry about it if you don't understand it all yet. It's hard to implement effectively, and if you're playing lower stakes people are likely just mimicking what they've seen pros do.

PS. I used to be profitable at 1/2 using only a 1/2 pot bet size, mixing some strong hands and bluffs in. It was not what the pros did, but it worked.

The only time I would do something different was when it was obvious the other guy wanted to call. Then I would bet bigger with the nuts and give up with bluffs.

It’s not exploitable because the big bet on the turn is supposed to be very low frequency. So you’re better off raising your strong hands on the flop, because the times you slowplay you just face a check on the turn most of the time. And this makes it really hard to get stacks in if the SPR is high.

I actually made a 4min video that explains why this small bet -> overbet trend is so common:

+1

Nice video

Does this mean that the caller should not raise any hands when facing a down bet, (particularly when OOP), and almost treat the turn like it is 'checking through', so that the flop down bettor thinks he has his opponent's range more defined when actually he doesn't? This lack of clarity should in theory then lead to mistakes being made by the down bettor on later streets.

Slow playing flop to remain uncapped vs a potential turn overbet is certainly a high EV move that u want to have in your arsenal.

But the EV of raising flop with a polarized range is also very high.

So u gotta look at the opportunity cost.

The best I could say is that u wanna do both at some frequency.

Correct, and at equilibrium we usually favour raising because if we slowplay too often villain can adjust by being more cautious when we call. And this would make the ev of slowplaying dip below the ev of raising.