One topic that is vital to your success in poker, and in Sit & Go’s in particular, is pot-commitment. All forms of poker revolve around not only a deck of cards but odds and probability. For example, most players know that a pair versus two overcards is approximately a coinflip, with both hands having around 50% equity. But even when a strong hand is all-in against a weak hand the weak hand will have some equity, and if the price is right it may be correct to play. For example, a low pair against Aces may win only 18-19% of the time, but with 5-to-1 pot odds it would still be correct to call.
Similarly, if you have most of your stack posted in the big blind you would usually be correct to call with any two cards, for example with 2-3 offsuit you would still have 28.5% equity against the top 15% of hands.
Using such principles it is possible to come up with general rules for situations in which you will have to call a bet or raise no matter what, because of a combination of hand ranges and pot odds, and this is what is referred to as being pot-committed. If you have more than third of your stack posted in the big blind you should usually call all-in with any two cards, since you will be getting such good pot odds. Also, if you raise and are reraised all-in you will definitely be pot-committed if you are getting better than 3-to-1 and should often still call getting 2-to-1 depending on the situation.
Adapting for Sit & Go’s
Pot commitment in Sit & Go’s is slightly more complicated because of ICM considerations (read some other Raise Your Game articles to learn more about ICM), where pot odds will seem more attractive than they actually are because the benefit of winning extra chips is not as great as the harm of losing the same amount. But the basic principles still apply, and when getting very attractive odds you will still need to call. However, in marginal spots or extreme situations like being on the bubble with high blinds you may want to consider other factors too. For instance, if someone is about to blind out before you or will be forced all-in if you fold, pot odds may become irrelevant.