This can kind of be a generic spot.
1/2 NL

Hero - $375 stack, dealt KK utg +1. Open to $12.

Villain - $600 stack. Is to my immediate left and raises to $40. Folds around to Hero.

I hadnt been at the table long, maybe 1 hour. Not playing many hands. Villain is a young guy who has played 5 or 6 hands and won most of them. By association of one other young player who I am familiar with, the villain is probably a solid player as well.

I call $28 more looking to check raise the flop.

Flop A J 6 rainbow.

Hero checks. Villain bets $60. I puke.

Should I always be playing back in this spot pre-flop? I'd just hate to have $120 in there rather than $40 on flop with an A. My stack size seemed like id have to shove any flop if i 4 bet pre flop.

$300 or less I'm getting ai with KK every time. $375 is a little deep, I don't mind flatting because I really don't want to 4bet/fold pf.

Great flop for you, JJ got ahead, AQ got ahead, AK got ahead, all you still beat is QQ and a rare possibility of TT, c/f.

Pre - Because of your raising position and his 3-betting position and the dynamic between the both of you(he probably views you as a solid player as well) I like the flat.

Flop - Check/fold is best. We're losing to 6 combos of AK and 3 combos of JJ and we're ahead of 6 combos of QQ and tied with 1 combo of KK. Since we're ahead about 1/3 of the time it's really marginal at best and it's going to be really hard to play future streets.

This is villain dependent. In general if 4betting will fold out everything but QQ+ or KK+ then flat obviously. If you 4bet and can get hands like TT, AK to call (or even 5bet you) or even worse to call, then this is a clear 4bet. Im sure many posters will disagree but this deep I think flatting is best and its not even close. Even a lot of bad players can fold JJ, AK to major aggression pre especially this deep. Also note that an ace will only flop 23% of the time if all aces are still in the deck but only 18% of the time if villain holds Ax. You shouldn't 4bet just because you're afraid of an ace popping up or flat because you want to lose the min against Ax. You 4bet or flat depending on villains continuing range to your 4bet, etc. As played on flop I would check call flop and check fold turn. Bet small on river for thin value if it checks through on turn. Villain could easily be making a cbet with QQ or worse and it's likely he will shutdown if he doesn't have an ace as AK, JJ make up a large portion of your range

Check fold flop as is fine as played as well. You're definitely beat a lot here. You do beat TT as well

I'd 4b call pre cos we're oop I don't like flatting with KK OOP ever although our flatting range widens it to like 88-QQ, AK,AQ,

Ship it with your 4b.

I like both flatting pre and shipping pre, depending on my V

AP, check/fold and curse the cards!

Flatting is fine against another TAG. Problem is when a board like this comes off you should be folding. As stated all his weaker range just caught up and you still have 2 more streets to to. Do you really want to be stacking off with KK on an Ace high board? Fold and move on you did what you could in his spot. If the flop came 10 high who knows you could of won a huge lot off of JJ or QQ.

I'm fine with the flat sometimes but mostly 4b to $125.

The flop is interesting... So he doesn't have aa.... I flat here and see what he does on the turn.

Add me to the flatting 3b camp.

I'm skeptical that Villains who fit this description are going to 3b in EP with JJ/TT very often, though. I'd heavily weight this toward QQ+/AK pf. As played, c/f flop. If we knew Villain would never double barrel QQ or check back AK ott, I'd be fine with a c/c, c/f line, but in reality we'll make more mistakes on the turn & river than Villain will.

If villain will bet his entire range here call the $60 and hope he doesn't bet the turn. If he bets again fold.

4 bet to 100 get it in preflop. Puke fold the flop although it might not be horrible to peel the flop and see if he shuts it down.

I saw a post by Bill Hubbard on dc that advises "clicking it back." 4bet here. This will help you define his hand. If he calls, it is so unlikely he has AK (AK never wants to see a flop) and never has AQ. If he repops, get it in vs AA, AK or QQ. Your equity is still fair against his range.

You have 57% against that range but that's assuming all combos of QQ and AK which is unrealistic. Almost all llsnl villains would flat your 4bet or fold with those hands pre. If you listen to bills posts here, it's likely you will realize that he would likely recommend 4betting small to like $80 or $90 and then folding to a 5bet. We get flatted by worse hands and get value and KK+ 5bets allowing us to lose the minimum at the same time when beat. I like this line too.