Just after pocket aces, pocket kings is the strongest starting Texas Hold'em hand.
Whenever you hold pocket kings preflop, there is only one hand that you're behind, namely pocket aces. However, unless you have a very strong read on your opponent, you shouldn't worry about him or her holding that hand. It has been proven statistically that ever folding pocket kings preflop is a losing long-term play. Don't do it unless you have an excellent read on your opponent!
It's very easy to play pocket kings before the flop. However, in order to maximize your profit, you should have a good knowledge of your opponents. Are they tight players? Are they lose players? If they are tight players, you might do best to check-raise if you're in early position. However, if you receive kings in early position and you're against a bunch of lose players, you should consider putting a strong raise in order to thin the field or get everything to call with a weaker hand.
One thing you should remember is to never let more than 2 or 3 players see the flop. Pocket kings don't fare too well against multiple opponents as you can see in the following table:
|Your Opponent's Hand||Chance of Winning||Chance of a Tie||Chance of Losing|
As you can see in the table, the only hand that has you crippled with just a 19% chance of winning is pocket aces. However, you're a huge favorite against any other hand before the flop. That's what makes pocket kings such a powerful hand to play.
Now it's the flop. You don't have to worry about pocket aces now, there are many other hands which could beat you now as well. The one card that you don't want to see on the flop is an ace. Consider mucking your hand with small losses if there was significant action preflop and there's an ace on the flop.
You should also watch out for mid-high paired boards such as 99J, 88Q or 1010Q, as it's likely that one of your opponents has flopped trips. However, don't let that discourage you from playing or trying to maximize your profit from the hand. Just make sure that you make the best possible read on your opponent and that you put him or her on a hand.
Should you instantly much pocket kings when an ace falls on the river? Remember, if you're only up against four players holding random cards, there's only less than a 50% chance that one of them has an ace. However, since most players play ace-rag preflop, it's much more likely that one of them has an ace, probably in the neighborhood of 70-80%. If there's a bad and a call, you should consider mucking your kings. You can also make a continuation bet to see where you stand.
If there's no ace and based on the available information you believe that you still hold the best hand, you should play your pocket kings very aggressively. Yes, there will be many hands that beat you, but chances are that you will still be ahead, especially if there are straight or flush draws out there.