Another installment in my analysis of the concepts at the end of No Limit Hold 'Em: Theory and Practice by David Sklansky and Ed Miller.
Concept No. 22: Ace-king is a powerful "move-in" hand and frequently moving in preflop is by far the best play with it.
I think this is a powerful idea that is underutilized by many of the good players I play with. Sklansky won me over to this idea when he introduced it in Tournament Poker for Advanced Players.
AK has a negative reputation as being kind of a "sucker" hand, since it is rarely the favorite if another player puts lots of chips in before the flop, because the other player usually has a pair or another AK. I think this reputation is undeserved. While it's true that AK has less than 50% chance against many other strong hands, it is only a big underdog against AA (6.5%-12%) and, to a lesser extent, KK (~30%). Against other pairs, AK has 43%-50%. There are three points that I think are misunderstood by players who think it's a sucker play to move all-in with AK preflop.
1. Players put way too much emphasis on having 50% equity when all-in. Whether a play is "correct" is determined by calculating (or guessing at) the play's expected value (EV). Actually heads-up winning percentage is only one factor in an EV calculation. When you are raising all-in, your EV depends only on the size of your raise, your pot equity (the amount in the pot after your raise is called times the probability you will win), and your fold equity (the amount in the pot before your raise times the probability your opponents will fold). Because fold equity is always positive, the required equity (when you are called) to make raising better than folding is always less than 50%. Having a higher probability of winning when you are all-in is nice, but it is only one factor to consider, and the difference between 50% equity and 43% equity is pretty small. Using the criterion of having a 50% or better chance against a certain hand or range of hands is wrong. It misleads people into thinking AK is worse than it really is because AK often falls just below this threshhold.
2. If you hold AK, this reduces the likelihood an opponent could hold AA or KK, which are really the only two hands you need to worry about. Players do understand this, but I think the effect is underrated. There are only half as many ways to make AA or KK when only three of each are left in the deck. If you hold AK and your opponent's range is AA-JJ, there is only a 1/3 chance he holds AA or KK, and your equity is about 35% (38% with AK suited). Note that when your opponent's range is this small, your fold equity is likely quite large.
3. Many players tend to view a big preflop raise by a good player as AA. They will often fold JJ or QQ, and some will even fold KK in certain situations. Although this means you are usually way behind when you are called, your fold equity is enormous.
Good players tend to play very tight ranges when there is a lot of action preflop and not much money left to play with after the flop. Players often fall into the habit of playing only AA or KK in these situations, sometimes QQ. AK is the perfect hand with which to balance your big-pot play before the flop. In some situations where your opponent's range is especially strong, it can certainly be correct to fold AK before the flop, but I think this is done way too often. Players are missing out on lots of situations where moving all-in with AK (and especially AK suited) is a +EV play.