Ok, first of all, if you 5bet, there is only 1 sizing possible. You cant bet more than about 36% of your stack without having enough equity to stack off on A5s or a small pair against most ranges. It may be different this deep when his range is heavier on AA but you can probably still profitably call a shove after raising to 1k on your high eq bluffs so its either call or shove.

Lets work out what we are against here. ill assume he opens around 13% and 4bets around 17% and calls 33%, folding 50%. We risk 1400 if we shove A5s to win 800 plus we heavily block AA so he needs to stack with at least 40% of his 4bet. This is his value part, which he raised intending to stack off. 0.40.17.13, 0.9% so he's stacking with AA-KK. You have more equity shoving Axs against that so good call.

Now, on the flop,the whole hand gets harder because the SB shouldnt be play like this and its difficult to put him on a range. His play is just bad and shouldnt ever be made with any hand. I figure QQ and JJ are the most likely hands he's doing this with. We shouldnt bluffcatch if we dont close the action since he can have many nutted combos. However, KK is stronger than a 0ev bluffcatch here so, if the SB is as wide as you think he is, im on board with calling.

UTG 4bet range should look something like AA-KK and 18 combos of hands at a lower frequency like QQ-AK-Axs-SCs etc. So on the flop, he very rarely has a set, we block his KK value bets, and we beat any AQs or ATs type of hand. We are only scared of AA. which he has 18% of the time but should check at some frequency.

Lets say that we call and SB folds, since we folded our bluffcatchers our range looks something super strong like KK-QQ and some JJ and strong draws at a smaller frequency. If he bets at any runout that didnt improve most of his bluffs like an A turn, we MDF and end up with a 0ev call on KK. I suspect he should rangecheck any non A turn tough, and we try to showdown.

Not going to leave some 3 paragraph comment. We have Kings. Lol I’d rather jam pre for 2 reasons
1. SB is getting 3-1 to call and most likely won’t be folding a hand he cold called 140 often and you don’t really wanna go 3 ways with so much in the middle already
2. If he does have Aces you’re never folding a 672 or any similar flop anyways. So yeah I’m just jamming and picking up $700 or getting coolered by aces.

What else do you call pre?

This was my friends hand, but I would assume he 3bets half the combos of TT (3), JJ-AA(24), AK(16), AQs (4) thats about it. Preflop I am in favor of jamming or 5bet to 900-1100 range. As played, I think he can call flop and evaluate the turn.

On this texture QJx or Axx he will definitely be over folding vs a 1/3 sizing. On low board he is stacking off with an overlay of sb range, sb isnt folding JJ qQ for 1/3 sizing on a low flop so Kk gains some value there. If he was deeper, I could see 5bet of 1200 and fold to 6bet, being live games AA is only hand they really 6 bet.

As played
Flop (1550) QJ5r
Utg 600, hero folds, sb raises to 1600, utg folds.

All hands were revealed, will save spoiler for later.

I will also say if 4bet was larger, where sb is unlikely to overcall, I could then be on board with flatting the 4bet and going Hu IP.

As the utg player what hands would you cbet 3 way in a 4bet pot on this texture?

Just as a short addendum: as long as we have an existing 5-bet/folding-range, it's not correct to say that we should simply shove, "just because we don't plan to fold against a 6-bet-shove anyways".

In this case I agree though that we likely are not 5-betting anything we plan to fold, so the result is the same - it's just about the argument. :)

And given the weird cold-call of SB, I'd rather jam pre than call.

BigFiszh