This article will detail what changes you should make to your standard heads-up game if you are heads up at the end of a major tournament. We'll discuss what you should look for in your opponent and how you should go about handling chops, even if you feel you have more experience than your opponent.
The first and biggest change to a typical heads-up game is the antes. Because of the antes, you're going to raise every single two-card hand on the button, for the rest of the tournament. Typically a balanced heads up preflop strategy will mix in limps and folds to create an optimal strategy, but in a tournament situation, both players should be raising every hand preflop. Failure to do so is an immediate loss. Create your optimal strategy after the raise: figure out the appropriate calling range for a three-bet and the appropriate four-bet range depending on how often your opponent is attacking your raises.
The second change worth mentioning is the fact that your opponent probably didn't enter the tournament expecting to play heads-up poker. In a lot of cases, it might be his first time playing heads-up, and so we're going to need to be able to quickly classify the player and adapt our strategy. The first thing to remember is that, unless your opponent has significant heads-up experience, he's going to be flying a bit blind at this point in the match. Most people are going to adopt a trial-and-error strategy... he'll play the same way until a lot of chips change hands or the effective stacks get much shorter.
Playing against opponents from different backgrounds
Depending on your opponents poker background, I've found a few things are true about his playing style in the heads-up phase of an MTT. If your opponent is an MTT grinder, but hasn't got that much heads-up experience, he's going to raise around fifty percent of his buttons, limp another 25%, and fold the worst 25% of his hands. If he's a good MTTer, he'll likely 3-bet relentlessly, usually when your stack is about 8-12x the size of your raise. If he's 3-betting you deeper or shorter, he usually has a strong hand.
If your opponent comes from a 6-max cash background, expect to play a post-flop game, and try to avoid this. Don't raise as often from out of position, and when you do raise, vary your play on flops. In position, check back mid/bottom pair, and check back air sometimes too. Most of these guys are itching to check-raise, so see that coming.
If you're playing against a fish (a dream come true!), keep the pots small and don't gamble with him. Minraise your buttons still, but don't call his 3-bets or button raises without a VERY good hand. If your hand is marginal, or you can't decide between two decisions, take the less risky approach.
Should you chop?
The last point I want to make is about chop considerations. Let's assume you've got a 5-10% ROI edge on your opponent, which wouldn't be unheard of, even though you're only 20-40 BB deep. If the 2nd place money is more than 10% of your bankroll, you should CHOP even-steven without any questions. Try to get a few % out of him, especially if he's wise enough to SharkScope you and see your heads-up experience. But, even if the best chop he'll offer you is an exact chop by chip count, you're doing yourself a favor, in the long run, by having the money you've already earned without risking it. I know chopping for 2nd doesn't have the same glamor as taking down a major tournament, but you'll have the opportunity to move back to to your regular with a padded bankroll and peace of mind that you made a good decision. If the difference between second place and first place is $5,000, you'd need a bankroll of at least $50,000 to enter a heads up SNG of an equivalent value. Even if you expect that you have a 10% edge in the game, you would be making a mistake by entering it.