I was playing a cash game online and I got pocket Kings. If someone else keeps raising me pre-flop, should I go all-in or should I hold back in case he has pocket Aces?
Well, I'd have to say "it depends". If you are going against AA then you are a 4 to 1 dog. Not a good situation. If you are playing against a super-rock (TAG) then it might be a fair bet that their super-aggressive play is advertising AA. However, those players are fairly rare and the average TAG is capable of going over the top with AKs, in which case you are a major favorite (~2 to 1). This is especially true, IME, in tournament play. In fact, the only hand you fear is AA - at least heads-up pre-flop. AA vs KK is pretty rare.
If you have other players in the hand, you want to push them out, so going all in is a good strategy. You don't want to go all in with KK (or even AA for that matter) against 2 or more players - ever - if you can help it.
You also should consider your own table image. Have you been playing a bit loose, making it seem reasonable that another player could push you around with a marginal hand? If so, then pound with KK - you're very likely the overwhelming favorite.
So, unless you have a good analytic reason to believe that your opponent has AA, then go all in. You'll very likely have the best of it. But, if you find that you're just "wondering" if they have AA, then you're likely just playing scared. Playing scared is infinitely worse then making an occasionally bad push against AA.
Remember, poker is played over the long haul. Just because your KK gets snapped off by an unexpected AA doesn't mean it's a bad play. Just like your AA gets snapped by the frisky idiot playing J4os - that's just poker. However, over time, getting your money in with the best of it more often than not will yield positive results. It's a mathematical certainty. Playing overly cautious poker - scared money - will always end badly.
It depends on a lot of things. The first thing to consider regardless of your cards is how well do you manage your bankroll ? If you are playing for all the money you have in your life then the answer is easy here... Even with AA you should fold, and you should leave the table and play some lower stakes.
Even if the math shows a positive expected value you would need to be able to do hundreds of all-ins to reach the long term and show profit. If you play for a one shoot it's pure luck. That said if you're playing for more money that you can afford to loose, don't take the risk because you won't be able to reach long term and beat random luck due to card distribution.
Now suppose the cost of your all-in costs you 50$ and you have a bankroll of 2000$ to play poker then you can considering the math involved and start thinking about long term poker.
The answer here is simple, if you have no history about your opponent, you should go all-in regardless of how many times he raised you during this specific hand. There are still enough players out there that look at their JJ-QQ and AK and think those are the absolute nuts!
If you have history on your opponent, and by that I mean you really need to know that player so well that you know he only reraises with AA. By that I mean you played more than 2000 hands (online) or like 1 week long in a casino with that player and he only reraised like two times during that period. Then I would consider folding my Kings.
As you described the situation here, I jam my chips in the middle !
If in doubt, call with KK. But there is one situation where there is "no doubt" and you should fold.
I disagree with others about the TAG (tight aggressive player). This person may have AA, but may also have AK or QQ. Against this "range," you are a favorite but will sometimes lose to AA. Weaker players will have wider ranges leading to greater winning frequencies for you.
The person to fear is the TAC, tight and super conservative player. Has played three hours (or more) and never once raised. Showed down only a few hands, including KK, QQ, and AK. In that three hour time period, there is about a 50 percent chance s/he will get an AA hand. This is the one time this person raises. S/he's got AA. Fold.
You are only behind KK+. You have 50% equity on QQ+. Mathematically you should call if their range is QQ+.
If they raise you a lot pre flop no way their range is KK+. If their range is KK+ then they would only be raising 2/221 hands. If you are holding KK then the random chance of AA is 1/221.
I they are raising you loose like 1/4 of the hands then KK is a 3:1 favorite. You should push with 99+ and AKs. Then you are a 2:1 favorite and play more hands.
You have to be really really good to muck KK in NL no matter what stakes or games you're playing and be profitable.
Until such time as you have seen millions of 👐 s go 👋, you'll always be a sucker for mucking here.
With a little more context you can make the case but for such ambiguity the answer is no, do not fold.