Hey, you need a high samplesize on villain to make the assumption that he really has 15% 3bet in that spot. Is it 6max or fullring?

The Spot is not really common btw. in 87% you fold UTG, in 13% you raise and if you raise in 85% of cases MP folds (normally around 92% fold).

Lets have a closer look on that spot from theoretical point of view:

If you are UTG and openraise, the whole table has to make your weakest hand indifferent between raising or folding, they do that by 3betting or calling with optimal frequencies, accumulated you'll face a 3bet in ~30% of cases if you openraise UTG at an optimal table.

If MP 3bets against UTG, the whole table has to make his weakest hands in his 3bet-range indifferent between 3betting and folding. Means: CO-BB cold4bet or call (I think cold-calling is bad btw.) a certain frequency and helps you to defend your range. Your range defends only partly against 3bets from MP in that spot, thats why you easy can fold a lot.

Okay, practice:

Firstly, if you openraise 13% from UTG, the villains should exploit that by folding a bit more because you are too tight.

Villain obv 3bets too much, the other guys can exploit that by cold4bet slightly more and you can add up some more 4bets, but you dont have to do that and the other guys dont have to that also, because the EV of all your defend-ranges increase a lot if villain 3bet twice as often as optimal because your ranges are strong!. All his non-optimal bluffs should have an negative expected value. Okay mabye it is +EV if the table is super passive but thats not your problem if you defend accurate or "normal".

If you fold 66% and villain in MP "exploit" that because of your stats, he is doing something wrong and start to exploit himself.

If you have a well constructed defending-range you're not forced to make a change. Please note you need a huge samplesize because the spot not occure very often, if villains runs hot in that spot on 10k hands in your hud this stat can be very falsified.

You can post your gameplan UTG vs. MP 3bet here and I can check that. But please note, if sizes change, we have to change our strategy.

There are some spots where you should start to change your ranges in an exploitive way to maximize your EV, for example if SB raise way too much and your in the BB, or BB 3bet way too much and you are in SB. But in most spots, well constructed, unexploitable (or hart to exploit) ranges should work well enough.

First of all, thank you for your help.
Here's my UTG game plan when Im getting 3bet by ( MP, CO or BTN):
My default plan is to defend 36% of my opening range, which is 4.9% of hand ranges.

4B: AA-KK, AQo,AJs,ATs.
Call: QQ-99, AKo, AKs, AQs, KQs.

I wasn't sure if defending 36% of my range is good enough if he 3bets that often. Shall i start calling wider?
Or I dont even have to change since my range will be much stronger and assuming i play well post flop my default strat will auto exploit him.

Obv it depends on villains 3bet sizing how and how much you defend.

But positions of the 3bettor have impact to an optimal defend-strategy too, against CO you defend more than against MP and you should defend slightly more against BU than against CO.

I dont like to have much bluff4bets in my range when I face a 3bet in UTG, because 3bets are usually strong against UTG, if villain play shove or fold after a 4bet it is okay to 4bet some bluffs.

I furthermore think that AJs and ATs are better calls than KQs, because KQs is often dominated, AJs blocks AA thats good, but a lot of player like to 3bet-bluff Axs (thats a good strategy) thats why calling with AJs is better than 4bet, because we keep some dominated hands in villains range + we can suck KK and QQ + we can make high equity draws or straights, when villain has some sets or twopair/overpair in his range.

But calling KQs isn't bad.

AK: I think AK playes better as IP call, OOP sucks. AK is the best blocker-combo and if villain calls, he'll call weaker hands or flips, shove against our 4bet is ugly but mabye the EV(4bet AK) > EV(call AK) oop. And think about folds, if villain folds to a 4bet IP he almost always fold some or much equity against AK, thats a big deal for your hand.

Pockets as call are nice, 99+ should be fine but it depends on sizing and position, mabye 99+ against big 3bet UTG vs. MP, 88+ vs. CO, 77+ against BU. If you have to add more hands because off small 3bet-sizing, you should start with pockets down to 77 or 66 and add up higher suited broadways/connectors, lastly the AQo stuff, because AQo is a very bad hand oop in 3bet pot.

Yea i would agree players dont tend to play shove/ fold that much after UTG 4bet as we are usually more polarized i guess.
After taking your suggestions, I have made some adjustments to my range, here it is:

4B: AA, KK, AKs, AKo, AQo ( bluff)
Call: AQs, AJs, ATs, QQ-99, KQs.

( vs weaker ranges or smaller 3bet sizing, add 88,77,QJs, JTs)