Explain your thought process. Opponent was about 34/25/2.5 after 50 hands. I've been playing super tight around 12/9 since my table was very very loose. Stack sizes say it all.

Opponent seems to be positionally aware, likes to steal and was 8/8 100% at showdown.

Do we raise, fold, or call in this spot PF?
Poker Stars, $0.10/$0.25 NL Hold'em Cash Game, 6 Players
SB: $3.85
BB: $9.50
UTG: $5.95
MP: $29.15
CO: $24.60
Hero (BTN): $48.40

Pre-Flop: K J dealt to Hero (BTN)
UTG folds, MP raises to $1, Hero?

I probably just fold since it is MP vs CO. If I have always just folded when he has raised and I had a hand I was planning to open with, I might 3-bet, but I'd prefer if he was raising from CO. If he is in CO and I am OTB, I am probably floating him with KJs and 3betting him with KJo. If you haven't played back yet, you should have at least one free light 3-bet coming to you, so I would probably 3bet the lower end (and KK+, AK) of my button steal range next time I am on button and he opens from CO, and call/float the rest of the range. And any hand I call with, I am almost always floating flop.

3-bet often to narrow his range both in the hand and to make him think twice before raising into your button - let him know you have position on him. I would mix in 3-bets and calls and rarely fold KJo but I prefer a call with this hand. Depending on board texture try often to push him off whatever trash he has after the flop. You could just fold if you're not confident playing this guy after the flop and it wouldn't be bad. Just make sure you punish him for raising light by 3-betting him often with solid broadway hands and mix in some SCs and small PPs also to widen your 3-bet range so you're not giving away your hand. He'll have to tighten up or be continually playing big pots OOP with inferior hands which is a losing proposition. When he tightens up make sure to re-adjust your range for 3-betting him again.

I'd fold 80%, raise 20%.
So in other words, he's less likely to open raise garbage in MP than in CO or BTN? Makes me more likely to fold.

I would usually fold it to a raise, but if I think opponent is raising lightly - I will 3-bet once in a while simply to take it down preflop. If he calls the 3 bet - I play postflop very carefully and if he 4-bets - I fold.
I don't like cold calling because it will be difficult to know where I stand postflop!
I like to try a 3-bet also because in the future - he may be more inclined to give me action if I 3-bet with AA or KK .

You can't fold this hand.

I lean toward a call for the following reasons:

1. You have position
2. You have a hand that doesn't play well in a big pot so 3-betting is a bit stinky here (unless it is purely to steal but this isn't a steal type of hand).
3. You are way ahead of his range
4. Blinds are short and if they have a brain they will realize that your 3-bet range is pretty wide here and could easily push a wide range over your 3 bet. If they push you are behind anything they make this play with but will still have to call the SB and most likely the BB.

Bob's your uncle.

Good job of paying attention. I had no idea we were in the button. In the HH we acted right after MP, so I assumed we were in CO. I also missed stack size of blinds, which I agree makes hand more playable since they can't squeeze.

I still think folding is fine here, but 3-betting and calling are better than if we are in CO. I think we are not ahead of villains MP raising range, so I prefer a 3-bet to a call to take it down right away. KJo really isn't that strong, and I would think it is in the lower end of an MP opening range even from PFR25.

Folding is fine because we don't need to play back as much against someone 2 to the right as we do against someone immediately on our right. But not folding is okay since playing from the button rocks so much harder than from the CO.

KJ is definitely way ahead of his opening range here if those preflop stats are at all accurate.

I liked all your points but the 4th one is not true/valid in this situation. I removed it and replaced it with my thinking. There is no evidence to suggest your reraising range here is wide. Very few people light 4bet in this spot at 25NL. Not sure why you said this, I would guess you don't play in these games. This is more likely to be true at 50NL, but is definitely not the case at 25.

This seems about right to me. Your default play in this situation should be a fold, but since this guy is so aggressive you can mix in 3bets here and there. Make sure you fold it most of the time, though. Flatting his raise is bad because you'll find yourself in a ton of nasty RIO situations. Maybe if it was sooted I could see some merit in a call, but offsuit it's just ugly.

SO lets say positionally aware PFR of 25 is opening 15% of hands from HJ. Our equity wih KJo is 40%.

Let's say they are opening up 25% of their hands from HJ (which obviously is much higher than a positionally aware player with a total PFR or 25 would). Now our equity is 47%.

Our KJo is definitely behind their range.

These equity numbers don't really mean anything. We are playing a pot in position, not felting the hand pre against his entire range.

OK, let's try this. KJo is around the 10% range of hands. For us to be way ahead with it, villain has to be raising way more than the top 20% of hands from HJ. Sure we have a positional advantage, but KJo plays like crap post flop and we can win a small pot or lose a big one.

Well his pfr is 25% so his range from mp is going to be about 25% maybe a little less like 23%. We have position and he's a "lag" at 25 NL so he probably sucks. Personally I would just 3 bet but I don't think calling is bad if you can just play well postflop. Never really considering folding.