It should be as part of the preflop strategy because it helps to not overfold vs 4bets. So you can 3bet more hands while not overfolding vs 4bets.

When villains don't 4bet bluff you can exploitably start not 5bet bluffing

Theoretically, the answer is yes - Your 5bet jam range should be balanced with an appropriate number of value and bluff jams.

In practice, whether a bluff is profitable or not depends on how frequently Villain will fold. How often do live players who 4bet fold to a 5bet jam?

To unpack this, we have to know how frequently Villains 4bet for value vs 4bet bluff, and how often they fold their bluffs. I don't have any experience playing live high stakes, but just from what I've seen online... I don't see a lot of folding pre-flop. When egos are involved, they will often flat their 4-bet bluffs (like suited connectors) and try to connect with the flop.

So... If 5-bet bluff jams are unlikely to work (Because Villains 4-bet range is skewed to value and they are still likely to call with some of their bluffs)... In practice, they might not be profitable.

I never understood this- why at any point bluff all of your chips? Would Chip Reese encourage this? I understand 4 bet bluffs but why ever bluff off all of your chips against a previous bet that most of the time contains a big holding?

there is not really such thing as a 'bluff jam' pre-flop. you can be jamming with a weaker hand than usual but it is not really a bluff because it has some kind of decent equity vs the calling range. say around 30%.

i'd say that it is not a very good play, really. unless the guy is a 4 betting maniac and STILL HAS TO BE FOLDING TO 5 BET JAMS, then our hands such as A4s are -EV by a lot when 5 bet jamming. because lets say some guy 4 bets a ton, he might just be expanding his 4 bet/call range such that he is now doing so with hands such as 88 and 99. so we might look at his stat and think his 4 bet is too high, this A4s is a good jam. but it isn't, because he is still only folding 20% of the time to a 5 bet because he has just expanded his stacking off range by 4 bet/calling hands that would usually just flat the 3 bet.

and also, A4s/A5s seem like decent hands to 5 bet jam, but in reality most of the guys 4 bets are gonna come from Axs hands, so we actually block them and unblock all of his big pairs. so unless the guy is mixing his strategy, 4 betting some % of KQo, QTs etc type hands then these jams are now, in fact, terrible jams. vs someone who 4 bets mainly just Ax hands then it is much better to 5 bet jam a hand like 77/88/99. as we unblock all of his 4 bet folds and are still flipping vs AK/AQ.

You can do math yourself(haha^^) and formula is going around in internet or some books. So villain start 4betting too much? That doesn't mean anything. Can't just rip it in with 22 or A4s and expect to make money in long run.
We shove A5s because it has good equity vs calling range (around 30-31%) and we have fold equity. Without fold equity you will be losing ton of money by jamming it. As well as having decent fold equity we will make money basically shoving any high cards AJo, KQo. That ''decent equity'' also depends on our stack size, villain 4bet size and rake. Opponent should fold vs 5bet moreee than 50%

You should understand when you should have a 3b/5b jamming range so that you can 5b jam when the situation calls for it. If you constrain yourself and say, "i'm never 5-bet jamming" or "i'm always 5-bet jamming A5s/A4s on top of my value range" then you will be burning money in a lot of spots. A GTO strategy will likely always 5-bet jam a # of combos on top of value range, but in practice, it's better to approach it based on player tendencies, or, if you're playing an unknown, based on population tendencies for the game/stake you're playing. At lower stakes, you can probably get away with 5-bet jamming less as a bluff in general (though it's not ideal still as there are opportunities to 5bet bluff jam vs certain players even at lower stakes), but as you move higher in stakes, good players will be able to play vs you very easily if you have a value only 5-bet range. Your fold to 4-bet will be very high or your 3-bet % will be very low, both of which, makes your opponent's lives easier.

The 20% 3bet range is linear in most cases. That means it includes a lot of low/mid pairs and A5s type hands that can 5b jam vs the right opponent (I'm mostly talking about a BTN that is trying to punish a wide 3b range by 4betting a ton). I don't know how profitable it'd be flatting a 4bet with A5s or 55. In my opinion, those hands make better 5-bets (assuming BTN is out of line 4-betting and is folding to a lot of 5-bets). I'd rather flat the 4-bet with hands like AQ/KQs etc. But A5s is a bit weak and will be tough to combat a 25%-33% range c-bet.

Also, it shouldn't be too hard to find 4-bet bluffs on the BTN. Hands like Ax offsuit, KJo etc. are not super enticing flats but make good candidates for a 4-bet.

As far as size of 3bet, it just means it has to work more often than if we just potted it. It of course will work more often also as most players will naturally defend less vs a larger size than vs a smaller size. With that said, I'm not super confident which sizing is better vs a bot. Vs a GTO opponent I'd guess it probably doesn't make much of a difference one way or the other. I prefer 3-betting larger myself (2.5 --> 10x, 3x --> 11x) though I see players making it much larger (to which I respond by defending a bit tighter).

lower Axs and smaller pocket pairs should be heavily mixed pre-flop
and that 3 betting them 100% of the time is pretty exploitable

Agree with this from a theoretical stance. From a practical sense, playing 3-bet or fold does have its advantages though, mainly in simplifying the game tree for you.

and, as I said, a smart, aware bb will expand his cold 4 betting range
if you are 3 betting 20% of the time vs the btn from the sb. so 5 bet
jamming these hands vs a cold 4 bet is even more suicidal (his range
is much tighter than the openers, and he has only 1 bb invested) and
now you are probably folding much more than 50% of the time vs 4 bets.

It's only suicidal if he's not out of line, in which case, it would be very spewy to jam A5s/55. I think that'd be pretty bad to do in practice vs an unknown.

My 3-bet from the SB will also display around 20% from SB v BTN to anyone whose isolating this stat. However, that's not a static 20% and will range from 15-25% depending on the BTN's tendencies as well as how cold-4bet happy BB is. Vs a BB that is cold 4-betting out of line, I'll simply expand my 5-bet range, but not polarize it such that A5s or 55 is a 5bet jam (I'd be folding those in most cases unless BB is super out of line and I think I have a ton of FE). I'll just start jamming with AQs/TT etc. You can argue that those make better calls, but I don't think calling OOP vs the cold 4-bet with a hand that looks like what you're repping is that great.

Also, the BTN will also be helping you defend vs BB's cold 4-bets so you don't need to meet the MDF by yourself. Plus, because of how expensive it is to cold 4-bet, his play needs to work a lot more often and that translates to SB and BTN not having to defend as much.

now i'll just 4 bet call you with 88 and let you punt in A5s or 5s.

That's the right adjustment in some situations, but that doesn't make the A5s or 55 jam necessarily bad. If we have the right balance with FE and equity vs your 4b/calling range with A5s, then it's still a correct jam. Not to mention, the value portions of my range are now making more money than they would have otherwise because I get to get it in with TT vs 88 etc.

these hands don't play that great in 4 bet pots vs tight flatting
ranges. A5o vs a flatting range that is mainly big suited broadways,
big suited aces (which dominate us) and some low suited connectors
that are just looking to hit a random pair or FD to x jam on us. and
when we hit top pair with A5o or KJo it is not exactly disguised as
most of our 4 betting range revolves around Ax and Kx.

They don't have great playability, but that's the reason why we are considering them in the 4bet or fold region vs the call 3-bet region. They have good blocker properties and mainly we are looking for preflop FE. If a player with a nitty 3-bet % 3bets me, I'm folding these hands (and I'm probably over folding which is theoretically exploitable). If a player with a 60% fold to 4-bet, 20% call 4bet and 20% 5bet 3bets me, and there's no dynamic that would make me think he'll be playing differently against me, then I'm happy 4-betting Axo since we're essentially free rolling the flop. We have 2 cards (equity), position, and initiative. We also can fire cheap 25-33% c-bets that need to work very infrequently to profit on favorable board textures.

so yeah, I guess it's easy to come up with 4 bet bluffs on the button,
but it's not as easy to come up with ones that have some sort of
post-flop playability in 4 bet pots. where as the sb flatting range
consists of hands that are EXTREMELY playable and want to see a flop.

True. But going back to my previous point, it's okay that our bluffs will have poor playability. They're mostly banking on preflop FE and they don't need to make up a ton of EV when they see a flop, but because we will still have initiative and a 25-33% cbet is still quite effective when we miss/we can hit a hand from time to time, it can be a better option than folding preflop (and we can't call the 3-bet since the hand has poor playability and we wont have initiative/FE by calling.)

yeah it has to work more often, which means that we cannot 3 bet the
exact same range for 2x pot than we can for 1x pot. say we 3 bet 20%
for 2x pot from the sb vs the btn, now we have just given both the bb
and the button a sick price to just jam in 66 and print a ton of money
as we are folding like 75% of the time to jams. and there is just so
much money in the middle, that they will now be incentivised to do so.
and if you start 3 betting 2x pot, probably the bottom half of your 3
betting range is now gonna be -EV vs a decent player who realised that
his AQo is now the nuts here as a jam instead of a flat.

At 100bb, if BTN opens to 2.5x and SB 3bet to 10x, BB won't be able to jam 66 and print money. Of course if you're 3-betting 2.5x to 20x with a 20% range, that's a different story. But the BB will be forced to either CC 3bets or Cold 4-bet as a defense against the wide SB 3-bet vs BTN strategy vs most large but reasonable sized 3-bets.

in theory u should be bluff5bet jamming, since opponent should be 4betting a little bit more than value4betting since also the bluffs have equity in the pot. so in theory u should do 5bet bluffing, but in reality its very often not profitable, bc most of the people are not 4betting often enough as a bluff. so in reality its basically completely player dependent, and u should be very careful with this since the overall playerpool doesnt 4betbluff enough.