If you’re ready to crush your opponents by outplaying them on the flop, you’re going to need a working knowledge of poker fundamentals. One of these is an incredibly important metric known as stack-to-pot ratio, or SPR. By figuring out our SPR and our opponent’s SPR, we can make better decisions and decide just how committed we are to the pot.
Basically, as the name implies, SPR tells us how large our stack is compared to the pot: SPR=stack/pot. For instance, if there’s 50 chips in the pot and we have 100 chips in front of us, then we have 100/50=2. On the other hand, if we had 150 chips, then our SPR=150/50=3.
You don’t need to calculate this to the exact decimal, but, like most things in poker, a rough estimate will get us most of the way there. Having 153 chips isn’t so different than having 145, and, for both of them, we can call it 150 chips to make our math easier.
Remember, SPR is ONLY used on the flop. Trying to apply this kind of thinking to the turn or river can be disastrous.
The Power of SPR
So, what’s the big deal with SPR? Why should we care about how many times the pot goes into our stack? Well, it all comes down to one important concept: pot commitment.
Pot commitment refers to a situation in which, given our holding meets a certain threshold, we cannot fold and give up on the pot. We’re committed to either winning the pot or losing our stack, and folding would put us in a situation in which we basically can’t win.
SPR helps us to figure out our pot commitment because the EV of folding is always worse than calling if the pot is large compared to our stack and we have a reasonable amount of equity. This tells us that, in low SPR situations, we are pot committed with top-pair or better hands. Basically, if our SPR is 3 or less, then we’re auto-committed with these types of hands. As our SPR grows, it gives us more room to fold and to make plays on later streets.
Once you get used to calculating and applying SPR to the flop for both yourself and your opponent, start thinking ahead while you’re still pre-flop. If you call that big 3-bet, what will your SPR be on the flop? Do you have a hand that your comfortable getting committed with?
Because of these considerations, we need to think about our effective stack size when forming our pre-flop ranges. If we have a big stack, we can more comfortably play cards like suited connectors because we can easily fold them, but, if our stack is shorter and we’re more likely to end up in a low SPR environment, we want to play bigger cards so that we can have more profitable shoves on the flop.