When you sit down at the table, how do you decide how many chips you’re going to put in your stack? Do you play differently when you have a short stack or a large stack? And how should we adjust our game to account for the size of both our stacks and the people that we’re playing against?
In poker at least, size matters. The way that you play both with and against a short stack should be different from the way that you play with and against deep stacks, and knowing how to adjust your strategy to account for this aspect can give you a +EV edge.
Measuring Stack Size
While looking at our chips in a real-life setting can give us an idea of stack sizes, it’s not always accurate because some chips are worth more than others, and we don’t have any visual aids in an online medium like Pokerrrr. Instead, we should measure stack size in big blinds (BBs).
For instance, if the big blind is 10 chips, then a stack of 100 is 10 BBs. If the blind is 50, then an equivalent 10 BB stack is 500 chips. We can say that these two stacks are the same size, 10 BBs, even though the actual amount of chips differs.
Conventionally, a standard buy-in is a medium sized stack of 100 BBs. Roughly speaking, a small stack is anything less than 50 BB and a large stack is anything above 150 BBs.
Stack Size Adjustments
The reason that we need to adjust our game to account for stack sizes is because of stack to pot ratio, or SPR. Because a short stack is going to face much lower SPRs on the flop, they’re going to end up pot-committed a far larger percentage of the time than medium or deep stacks.
This means that the short stacker should tighten their range and play less ‘speculative’ hands like suited connectors, instead preferring hands that they can be comfortable getting it all-in with on the flop when they hit top pair. Deeper stacks, on the other hand, have more room to maneuver in later streets thanks to their higher SPR, and this opens the door for more play with a wider range.
Remember, since the short stack should be playing with these considerations in mind, we need to adjust to that when playing against a short stack. If we have a deep stack on the flop with a high SPR and a strong draw, are we really going to be able to call a shove from a short stack? We know that their range is full of top-pair type hands, and so this call is much harder than a bet of the same size from a deeper opponent.
Essentially, this comes down to what is known as effective stack size. The effective stack is the smallest stack in play—since a bet can never be larger than that stack, it essentially removes the rest of the larger stack from play and forces both players to play from the perspective of the smaller stack.