I'm not a real expert, just have some thoughts.
Young/Aggressive/Pro = often is a GTO player
1) I believe that pre 3bet could be bigger against him, instead of pot size i would bet around 6-7bb. Just because he's aggressive, in position, his 2bb is already there, and you have KK out of position. 6.5BB is a nice invitation to Value town.
2) I think that checking the flop after that 3bet is good in just one case, if you've flopped a set. One rule works well against aggressive players, on the flop it's good to appear weak when you're strong and appear strong when you're weak. It's better to bet those 16K on the flop, instead of the turn. only 2 outs improve your hand, while so many cards can give you extra doubts and fears. Let him decide it on the flop - if he wants to go to the showdown with his cards and full stack in the middle, cause such bet on the flop, after 3bet will tell this to him.
Let's say i'm that villain player, what do I see?
let's say my hand is ATo
I see a pre-flop 3bet OOP. What is this? It's probably a good pocket pair or a strong ace 50/50.
Flop: A 9 6
-> Check
What is this? Why? He's out of position and not looking for value here? Why? Now I feel like he doesn't like that flop. 80% that he has underpair, 20% for a set of nines or aces
Turn: A 9 6 J
-> Bet 3/4 of the pot
What is this? is this a
bluff or value bet? It looks like a bluff, cause weak play on the flop after strong pre-flop play told me that more likely opponent has no ace. he wasn't looking for the value and didn't wanted to defend his hand on the flop, right now I think that it's a bluff or a set of jacks, or a well prepared trap. 90% for the bluff, 10% for trips/traps.
River
A 9 6 J 4.
Adding possible spade flush? Not really. What was that pre-flop starting hand for the flush? AsKs or KsQs? KQ is out of equation, cause OOP 3bet with KQ is a really terrible move, it leaves us with AsKs. He has it? IF he had it then most likely he would want some value on the flop, but he checked the flop. Right now he can have set of nines, set of aces or set of jacks. If he has it then more likely he will go for value with a pot size bet or little less, but not less than half of the pot.
-> But Hero CHECKS.
What? Why? I'm 95% sure now that he's not looking for value, 5% that it's a trap and Hero has the nuts. In this case I will always bet and will try to make it look like a hard to call value bet, cause all-in will look like a bluff or nuts with my remaining 70K stack, and I don't want my opponent to think that I'm
bluffing, I want him to think that it's a value bet, doesn't matter if my hand is 72os or if it's ATo like I've assumed above. This is how I will make it clear for me and for the Hero. So if Hero 3bets then it will be a hard decision for me if my hand is AT, and easy fold if my hand is 72 or KQ, but so far it looks like Hero is bluffing or has fear that his underpair is not good and I can represent Ace or set with a nice bet. And that's what I'll do.
My logic was correct and Hero folds.
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My hand is AT again and Hero 3bets 6.5BB preflop, my stack is 40bb, 2bb invested, need to add another 4BB. I'm in position, but it's another 10% of my stack, most probably I will see another 15% or more of my stack on the flop and something like 30%+ on the turn, most probably it will be all-in for me on the turn with such a start. It leaves me less room for maneuvering if my hand is weak, even if it's a weak ace like AT... Flop is A high, Hero bets 10bb and I realize that i'm against AK-AQ, Aces maybe, now there is no space for bluff for me, I can only call with ace or set, bluff 3bet isn't a good solution for me here.
