Heads-up sit and go tournaments are played with two players, the small-blind being assigned to one player, and the big-blind to the other. The button is assigned to the small-blind, and is rotated between the players along with the blinds, just like at a full table. The button acts first pre-flop, and has the advantage of acting last on each street post-flop. Conversely, the big-blind acts last pre-flop, and first on each street post-flop. Heads-up play requires serious adjustments to several different aspects of your game.
If I had to choose one word to describe heads-up sng poker strategy, it would be "aggression"; but there's more to it than that.
Let's take a step back and look at a full 10-handed table. The blinds hit you every 10 hands and you could essentially make a profit from playing a tight-aggressive style, and little more. Of course your opposing players will catch on to your super-tight style, so you would have to switch it up every so often. But essentially, you could make a profit from playing solely top-10 hands.
As you move to 6-handed, the blinds hit you more frequently - every 6 hands now - and you have to adjust your starting hand requirements to make up for it. Playing a very tight style isn't enough anymore since you won't be getting paid off with those premium hands often enough to counter the blinds hitting you at an increased rate. On top of that, if you are playing attentive players, they should soon catch on to the fact that you're playing premium hands only, and you'll have a harder time getting paid off. You have to widen your pre-flop hand selection to include lesser hands to make up for getting hit by the blinds so often.
Now as you move to heads-up play with only two players at a table, you have to be playing many if not most of the hands dealt to you. You will be contributing at least a small blind's worth every hand, and to make up for that you have to play with loose starting hand requirements. On top of all this, most tournament situations that you will be in are probably going to be low-M situations, essentially meaning you'll be playing with a small stack-size to blind ratio, which adds even more pressure.
You should not just be limping a lot more, because by raising with most of your hands, you will be putting extra pressure on your opponent and increasing the chances that you will win the blinds and antes. In a typical hu sng tournament, you should be:
You also will have to mix your play up occasionally to keep your opponents guessing, and I'd suggest occasionally limping with a strong hand or raising with a weaker one. Of course every hand is unique, and the rules I'm laying out for you don't apply to every situation. If you're raised by an absolute rock of a player, then you might reconsider re-raising with 77, for example. The guidelines I give serve the purpose of giving you a good idea of how to play versus your average online player. Unless you're facing a naturally hyper-aggressive player (which isn't uncommon), your opponent will probably be playing a little too tight, and you have to take advantage of that.
Since most of the time neither player will even pair the flop or really hit the board, post-flop aggression is also important. Middle and bottom pairs are often enough to win a hand, and top pair is often enough to stack off with. Any hand better than top pair should be treated like gold, and you should try to get as much money in the middle with it as possible. Pre-flop, the value of certain hands also changes. Suited connectors and small suited cards, ideal for multi-way, limped pots which give good drawing poker odds, have now lost a lot of their value. The actual card values should have more of an impact on your decision rather than the fact that the cards are suited or not. The value of pairs also increases.
A tight player might as well be defined as a weak player when heads-up. I can't stress this enough: aggression is key in heads-up play. Even a hand as weak as 32 off-suit should be limped in with if your opponent is consistently not raising when you do; if not for the sake of looser starting hand requirements, then for the sake of our next topic: pot odds.
Considering pot odds strictly, it is incorrect to fold your small blind pre-flop. Of course, poker isn't played strictly through pot odds, and this example holds true only if your opponent has not been consistently raising you when you limp from the small-blind. As an example, let's consider this sit and go situation:
With the blinds at $100/$200 and a $25 ante, the pot starts at $100 + $200 + $25 + $25 = $350.
With you in the small-blind and first to act, it's $100 to call into a $350 pot, giving you 3.5:1 pot odds. Those odds are good enough to call with any hand, even with a lowly 32 as I mentioned. Even in a tournament with no antes, you'd still be getting 3:1 which is plenty good enough to call; so based on the pot odds alone, it is never correct to fold pre-flop. But poker is never that simple. If you've noticed that your opponent likes to steal, and you have seen him or her raise several times from the big-blind after you've limped from the small-blind, then you have to adjust your play. You can no longer limp with any two cards, and should dump the lesser hands. You'll have to use your judgment as to the range of hands you can limp with based on how aggressive your opponent is being.
Here's a pot odds chart to keep in mind. This can be very helpful when playing after the flop to quickly figure your odds of hitting your hand. Of course you need to consider your opponent's hand in every situation. The Poker Odds Calculator is a great tool for trying different combinations and figuring out how each affects your expected value in the hand.
Getting a read on your opponent is much more valuable heads-up since you'll be playing every hand with him. Getting solid notes such as "over-bet pot with weak hand", "folds to 4+ BB raise" or "bet pot when checked to multiple times" will give you a huge edge in a game, assuming your opponent isn't observant to the same degree as you. Pay close attention, and adjust your game accordingly. Since your opponents won’t be completely unobservant, you should try to switch your game up and use your past play to your advantage. This will help to eliminate recognizable patterns in your game.
For example, say you've been raising constantly from the small-blind, and you can tell you put your opponent on tilt. He's all but ready to shove what's remaining of his chips in the middle. You're on the small-blind again, and look down to find AA staring right back at you. Here would be a perfect situation to raise it up just like you've done all along in the game, and hope he has a smaller pair or something like KJ and feels like taking a stand with it.
Position should also be a huge factor in your decisions. With position on a player, you have the advantage of seeing his move before you have to make yours. Thus you will be making your decisions on every street with more information available to you than your opponent has available to him. In heads-up play, the big-blind will be out of position for the whole hand, save pre-flop. This gives the small-blind a huge advantage. If the pot odds for limping from the small-blind were somehow insufficient to call, it would probably still be theoretically correct to limp because you would have position for the remainder of the hand, making up for any disadvantage that poor pre-flop pot-odds would give you.
This positional advantage for the small-blind, and the positional disadvantage the big-blind has to deal with also affects how much you should be betting pre-flop. At a full table, the normal raise is 3-5 big-blinds. There is usually dead money in the pot from blinds, antes and possible limpers, and so your raise has to be big enough not to give favourable odds to a potential caller. Coupled with the number of players, and therefore number of possible hands that could beat you should you let them see a cheap flop, a bigger raise to isolate or win the pot immediately is the best option.
Heads up, there is very little dead money in the pot, and only 2 players. This changes the size that the ideal bet range should be. It's been mentioned in more advanced strategy books that the ideal raise from the small-blind is to 2-3 big-blinds, but with the changes (and loose play) that online poker has brought, I suggest raising it to 2.5-4 big-blinds. That size of raise will be giving your opponent at best 2.33:1 odds. You don't exactly want a call while holding J9 in the small-blind, and a min-raise (2 big-blinds total) is going to be irresistible for your average online player regardless of his holding.
With that said, your raise from the big-blind should be much different. As I mentioned, you will have the disadvantage of being out of position the rest of the hand, and you'll need to raise much more pre-flop to counter that. Doing so will help ensure that you won't have to make such difficult decisions on later streets. You want to either end the hand pre-flop, or end it with a solid continuation-bet on the flop should your opponent call your pre-flop bet. I'd suggest a range of 3-5 big-blinds on top of your already-posted blind. A raise of that size gives your opponent at best 1.67:1 odds; poor enough to make up for your positional disadvantage, and it will hopefully push out the weaker hands. Of course again, this is just strategy, and the situation you find yourself in could be one where your opponent is willing to cold-call 10 big-blinds, so you'd have to adjust your strategy accordingly. Every situation is unique.
Great poker players excel in marginal situations, and heads-up play is rich with them. There are plenty of people out there who play heads-up without adjusting their game whatsoever, and because of this, there is a ton of potential profit with this quick, volatile form of poker. To make a decent profit, you'll need an ITM% (in the money) of somewhere over 50. How much more than 50% depends on the tournament fees paid on the game you play. Heads Up SNGs can be very volatile and require an aggressive style. With practice and a lot of study, an ITM over 50% is definitely achievable - if you play your cards right.
Article written by ChuckTs