A crucial ingredient in poker is to take stack size into consideration when betting, raising and calling. When a bet is just a very small portion of the total stacks of the involved players, this aspect can be irrelevant, but when a bet would make another player pot committed if calling, when it can be a very important aspect.
How to decide bet sizes in relation to effective stacks?
It’s common to refer a bet to a certain number of big blinds. In tournaments, there the blinds are increasing, this become ever more important.
Beginners and many intermediate players don’t take relative pot sizes into consideration when betting. They are only taking the size of the pot into consideration.
But it’s very different to bet 100 with effective stacks of 1,000 or 2,000. In the first case, if the bettor is facing a raise, a re-raise could mean all-in or make him pot committed on a later street.
So what do we mean with effective stacks? The effective stack is the maximum that a player can lose or win in a pot. To illustrate this clearly, let’s look at some examples:
Stack 1: 1500
Stack 2: 1250
Effective stack: 1250
Stack 1: 5600
Stack 2: 1750
Stack 3: 3400
Effective stack: 1750
The concept is not very complicated in itself, as you can see.
Bet sizing with the effective stacks in mind are a way of planing in poker. You don’t play good poker if you suddenly realize that you are pot committed on the river and are force to call even that you fell you are likely behind in the hand.
Bet sizing to make the opponent pot committed
The first step to win the opponents whole stack is often to make him pot committed. Obviously, this could be made by putting him all in, but that is too apparent to be effective except he has a very strong hand. To lure the opponent into being pot committed is done by a sequence of bets, although often only two.
The recommended bet size for this is to bet approximately 40% (as recommended by the authors of Kill Everyone) of the opponent’s stack. With 40% invested, it will be hard to not call another bet since the pot odds will be good. There is quite obvious that you want your opponent to be pot committed when your hand is strong, and you that you don’t want it when your hand is weak.
If you trying to win the hand by a two-barrel bluff, you will avoid to make your opponent pot committed.
How to compare stack size to blinds
Another factor that can be of relevance for the size of a bet is the blinds. Playing poker with small or deep stacks can be quite different when it comes to strategy.
Playing with smaller stacks are in the most cases easier. Not that you prefer a small stack in a tournament, but when the stack is small, the decisions are fewer and your potential mistakes not that big.
If you go all in with a small stack and an opponent is calling with a better hand that are not as bad as if it had happened with deep stacks. Doing mistakes won’t cost you as much if you have a few chips only.
You may also change your relative pre-flop betting size when the blinds are getting bigger. If the tournament started with 20/40 blinds and have increased to 200/400 that may change the way you raise pre-flop.
If you started with raising around 3x big blind when the blinds were 20/40 you might consider to decrease that to around 2,5x or 2x big blind. This is since the blinds in this situation will make up a bigger part of the effective stacks.