The Importance of Stack Size
Over the past decade no-limit Hold'em has overtaken limit Hold'em as the most popular variation of poker in America, Europe, and Arab casinos. On the surface these variants might appear very similar, but they play differently and no-limit requires a different strategic thinking. While the differences are many, this article will discuss just one important consideration in no-limit - varying play according to the relative size of your stack in comparison to your opponent's stack. The reason is that in no-limit Hold'em, the money behind is more important than the money in the pot. Ideally, your goal is to win your opponent's stack, which is often more valuable than the money in the pot.
Consider a situation in which you and your opponent are relatively deep stacked, meaning that you each have 100 or more big-blinds (BBs) in your stack. Under these conditions tough decisions can arise on boards that allow for big hands - like straights, flushes, or full houses. A common situation in which you have flopped top-pair with a good kicker on a board with two suited cards requires careful hand reading skills if your opponent calls your bet. Is your opponent drawing to the flush or continuing with a weaker pair? This would not be as a great a concern in limit Hold'em because your opponent cannot place a large bet on the river if a third suited card appears. A common line of play is to bet until the flush appears on the board and then check-call on the river. Your opponent is almost always getting the correct pot odds to draw to a flush and will call you down. There is nothing you can do to change the pot odds, but you only need to call one last bet on the river to verify the flush and it is almost always in your interest to do so.
However, the math in this situation changes drastically in no-limit. Your opponent could place a large bet or move all-in should a flush appear at the end. You cannot simply call under all circumstances because you risk losing your entire stack. It is not simply one last bet. On the other hand, you do not want to be bluffed out of a large pot every time a flush appears. To counter this possibility you need to place bets after the flop of sufficient size that opponents do not have the correct pot odds to draw to a flush. With a deep stack, you can "name your price" for draws. Noticing which opponents will pay a bad price for a draw and which will not also helps with your hand reading ability and defending against bluffs.
For example, consider play after the turn with two-suited cards on the board and $50 in the pot. You believe that you are ahead in the hand and that your opponent is on a flush draw. If the game is $5-10 limit and you bet $10, your opponent is getting the correct odds to call. The flush will arrive 1 out of every 5 times but your opponent is getting paid at least 6 to 1 on the $10 call and possibly more if you call his river bet. Calling your $10 bet is always correct for your opponent.
Now consider the same situation in $1-2 no-limit Hold'em with $250 stacks for each of you. In this situation you could place a $50 bet. If your opponent calls he is getting paid only 2 to 1 on the flush draw, which would make it a bad call. Although, if you are the kind of player willing to call an all-in river bet no matter what happens on the end, your opponent could potentially get paid 6 to 1 on his $50 call, which would make it profitable. It is these kinds of considerations that make deep-stacked no-limit Hold'em such a complicated game.
But, this same situation changes considerably against a short-stacked opponent. If your opponent has only 20 BBs ($40 in a $1-2 game) you cannot easily price him out of a draw. However, it is not possible for your short-stacked opponent to be paid off in a big way if he hits the draw. You will not be facing a tough decision on the river as to whether or not to call a large bet. The net result is that "made hands" such as big pairs go up in value and drawing hands go down when one or both of the players are short stacked. In fact if stacks are really short - 10 BBs or less - about the only decision to be made is whether to go all-in pre-flop. There are simply not enough chips available to set prices of any consequence after the flop.
These examples show that monitoring relative stack sizes - yours in relation to your opponents - is essential in playing no-limit Hold'em. The game is much more about winning stacks than it is pots, which means that it is often the relative stack sizes that determine correct strategies. In contrast to many online casino games, such as online roulette in which every bet has a negative expectation, skilled online poker players can place bets with positive expectations if they can correctly assess the situation and induce their opponent to place a bad bet.