A-K is one of the best starting hands in NL Hold'em. But it is much more difficult to play than K-K and A-A preflop. Deciding whether to raise/call/fold with A-K is an important concept to understand, one i needed to put in writing for myself though i hope others find it useful as well.
In all of the following situations, assume:
Opponents 3bet range: J-J+/A-Q
100x BB stacks
First situation: standard preflop raise(3xBB)
You should usually reraise in this spot. It prevents weaker hands from calling behind you, which would make your hand more difficult to play on the flop. It also gives you a chance to find out if UTG was raising with a strong hand, since he would probably raise again with K-K/A-A/A-K. Finally, being the last one to raise preflop is almost always the best way to take a hand to the flop. This is because if you do get called you can then c-bet the flop, allowing you to oftentimes take the pot down without having to flop a good hand.
Second situation: standard preflop raise(3xBB) with 1-2 callers.
Raising is even better in this spot than in the first scenario. You are trying to limit the number of players who go to the flop, since the more players there are in the pot the harder it is to win the pot through a c-bet/having the best hand. Plus, the pot size is now bigger, meaning that there is more incentive to try to win before the flop.
Third situation: preflop raise (3xBB) followed by a reraise(12xBB).
Calling is a bad idea in this spot. This is because when your opponent bets the flop (and you missed it) you won't know whether he has an overpair, or is c-betting with missed overcards. You will have to fold on any non Ace or King high flop, since a bluff has a low chance of succeeding due to the face you have not represented a strong hand up to this point.
Folding is ok, since it is difficult to play this hand on the flop unless an Ace or King hits. Even then you might be facing A-A or K-K, and lose your stack on any good looking flop when you do get action.
Raising is ok also, since you can now win the pot preflop. Plus, when you go to the flop any opponent that has stayed with you would have to be concerned that you are holding K-K/A-A. Almost all opponents will 5-bet (usually going all in) only K-K/A-A, though sometimes they will trap by just calling the 4 bet preflop. I would say that people are trapping with K-K/A-A when they just call a 4-bet probably 75% the time and the other 25% of the time they are holding Q-Q/A-K looking to see if you will push the flop (definitely a bad play, but there are some people who do it). You can fold to a push preflop, but you should bet strong on any flop if you are first to bet/ been checked to. It is your best chance to win the pot against Q-Q/A-K. Who knows, you might even get K-K to go away! :)
Of the choices (raise/call/fold), i like raising the best.
1). You have a good hand that's favored against most opponents 3-betting range.
2). You have the opportunity to make your opponent fold a better hand than yours at some point in the hand.
In the infrequently occuring scenario where there are three raises before you and you are holding A-K, i think you can fold and not lose a nights rest.
Being the first to raise with A-K is a little bit different. In many cases, you will just get called by 1-2 opponents and play a flop. I am going to be analyzing the cases where you are faced with combinations of callers/raises.
Fourth situation: You are first to enter the pot, and you raise (3xBB). An opponent reraises you (12xBB).
I think you should usually raise in this spot. Folding is a bad idea mainly because your hand is favored against most opponents 3-betting range. Calling is bad because your opponent is probably going to bet on the flop, and you won't have enough information to decide whether he is posturing a strong hand or actually has one. Raising gives you control of the hand, allowing you to be the one making the bet on the flop without a hand.
Fifth situation: You are first to enter the pot, and you raise (3xBB). 1-2 preflop callers, followed by a reraise(12xBB).
I wouldn't play my A-K any differently than i would in the previous scenario.
Sixth situation: 1-2 limpers before you. You are first to raise (3xBB). Action is folded around to the first limper, who reraises (12xBB). Second limper folds.
This is a frustrating situation. Most players won't limp raise as a bluff (quite a poweful play, though most players don't use it), so i would say you are against Q-Q+/A-K 90% of the time in this spot. You are not favored against this range, so folding is usually going to be the best play. If you have notes on an opponent that suggest that he more than likely to be bluffing 10% of the time in this spot, you should reraise him. Most opponents will give up on a bluff facing this much strength, so you can then fold to another raise/push.
Basically, i would reraise A-K in almost any spot. This is all i could think to write down. I hope some other people come along edit/add ideas to this post!
