I have a villain here, playing Barry Greenstein 2006 style.
Just wondering if he can be profitable...

1. He opens too many hands to up to 10x at 2/2 (unsure if this part is truely BG) But this achieves his first goal of getting HU or at most 3way postflop.
2. He goes on to cbet 80-90% pot on virtually every flop and turn.
3. Sometimes he will give up on the river

Of all opponents, I find him the most difficult to play and I have made some laydowns that are probably -EV, just out of fear, e.g. folding AJ on a J93T turn.
Another time, I folded JT on Q96J, to the 2nd 90% barrel on T, only to be shown 93o (should have probably jammed for 60% pot more)

He seemed to be pretty successful, getting the max with all his overpairs, sets. Plus getting folds from passive fish who like to call every flop when they hit a piece of it, but give up on T without 2 pair or better.
The only glimmer of hope was when I heard that he had barrelled AK 3 times vs a set to lose 250bb.

So, is this a valid/winning strategy in 2018 in low limit live games?

It depends. Given the table conditions you quote, apparently so.

It's all about Vs and table conditions. Many styles can win against the right Vs that would be crushed on other tables.

Doesn't sound like Barry Greenstein but does sound typical of many super laggy players. This sort of play can work but it's harder then more value oriented play. You have to be on the ball all the time and read people to know when to back off.

I see this a lot with people who can do this successfully for a while and then go broke. At 1/2 they usually can't adapt to playing stations and are running on thin bankrolls that can't handle the huge swings this style creates. At 2/5 the other players usually begin to adjust eventually and most people trying this can't make the range and bluffing rate adjustments on the fly.

Playing against them takes courage because you have to call down lighter then you would against a normal opponent. But it's usually pretty profitable, just plan on calling down on all but the worst run outs if you call flop. They are easily trapped because they won't slow down.

I think it's better to use Ed Miller's low stakes exploits for 1/2 and 2/5 games. Play tight, but double barrel a ton when you do play. I'm not a fan of splashy play.

Opening for a large sizing 4-6x is standard in live poker already. Opening 10x in a tight game seems bad but maybe you could make it work.

We should be cbetting a ton since our opponents play a wide/weak range preflop, don’t raise frequently or balanced enough to punish us for over cbetting. If we lock our opponent in pio solver for instance to do very little bluff raising, pio begins to cbet at a very high frequency. If we have a stronger range and our opponent doesn’t bluff raise we can cbet full range on most textures.

I don’t know what “give up sometimes on the river” means. Obviously we shouldn’t be bluffing every river, if anything we should be under bluffing rivers.

I often wonder if this is how you're supposed to play at every low stakes <100Bb game. It might be. It totally tilts the postflop nuanced types because it really quickly messes with their spr comfort zone. But when you're on a run of running into sets it sure does hurt.

Interesting, I ran into a guy with similar strategy. It's successful, because it's hard to continue with TT on J96r board. They love the initiative and just keep betting, if the are the raiser. Otherwise, they want to take initiative by check/raising. But, they shutdown, if get called on the flop.

On the table, it can disconcerting to fold TT and be shown A6o. Top pairs and pairs in general go higher in value, draws are lower in value, as he's check/folding a lot unless you have nut flush draw and he has smaller one. Play immediate EV hands faster and hands that need to see turn and river slower.

Interested to hear other people's thoughts. I did fold JJ against a huge check/raise he did on KXX with two spades and he showed spades, no K. But, I adjusted after that.

I had a friend like this. He had by far the biggest cbet% of any winning player I've ever seen live. Not 80% pot like op describes but ~40% perfectly merged across all his ranges. This somehow also earned him the lowest showdown% of everyone we knew. It was like watching a magician. He would bully everyone with these little relentless bets.

Low showdown means low variance. He kind of trained every table he played to just let him do it within a few orbits. Just seeing these end cases can really open up your game to the possibilities. Tbf, a bunch of people disastrously tried to copy him. His post flop discipline was otherworldly.

His motto: I don't really worry about my hand until they call the flop.

In a nutshell, against an opponent who will bet any two cards, we need be calling/raising on each street with the top 70% of our [remaining] range.

There are players who bet anything and everything. We call them whales.

This.

Sounds like you are just not adjusting OP. This player is not good and he should be one of the most profitable player types you ever get to play with. Just start with a better range than him and be a passive calling station after that. You should be willing to go broke with much weaker hands than you normally would.

And if we don't get cards that qualify as "a better range than him" just wait.

Maybe that session will be "the best game we ever watched".

But just one small heater will give us a mountain of chips if are just patient.

In fact, just one HAND might make our win rate for the whole session, patience grasshopper.

What you don't see are all those sessions where they miss their low probability draws and, as a result, have very little fold equity. But these guys aren't playing poker to wait for good cards, so they continue to click away and leave the table before anyone realize that these are the same "magicians" that seem to put the fear into everyone last week when they hit every 2 pair imaginable.

He also pounces as the non-aggressor.
Last night he was to my left. I open KTs in HJ, he calls. Flop T65 with possible FD. I cbet, he calls. Turn offsuit A. I check, he bets 90% pot at SPR=3 on Turn. I make the fear-fold. In hindsight this was a slam-dunk spot for calling down, or was it?

Good discussion on this sort of problem here. I'd ignore PokahBlows posts in the thread, though.

Apple and orange.

Macro approach against this type of players is to fold less with stronger range.

Micro approach is case by case. Folding less doesn't mean to never fold. Your specific example left out key variables and cannot be answered simply as call or fold.