In this poker strategy article, poker coach John “WhatA298” Bradley explains, why it is so important to know the Stack to Pot Ratio (SPR), and how to make use of this knowledge in game.
In poker, Stack to Pot Ratio, refers to the ratio of the pot size compared to the effective stacksize.
So, if the pot is $10, and you and your opponent have $100 in your stacks, then the Stack to Pot Ratio (SPR) is 10.
When you are on the flop, or any other street in fact, there is always a ‘weakest hand’ that you will be happy to stack off with.
There are many things that determine where you draw this line: preflop action, board texture, opponent type etc. One of the main factors, however, is SPR.
At an SPR of 1 on the flop, top pair is almost always a good stack off. At an SPR of 10, however, it becomes very loose indeed. At an SPR of 10, your stack off threshold is more likely to be two pair, or perhaps a set.
Players’ stack off ranges should be very elastic in relation to SPR. In reality, however, players’ ranges are far too inelastic.
Players tend to see some hands as absolutely very good (two pair, for example), and some hands as absolutely really bad (Ace-high, for example).
Everything is relative, and given a low enough SPR, Ace high is an easy stack off; while given a high enough SPR, two pair is far too loose to stack off with.
Knowing this tendency towards inelasticity in your opponents, you can lead them into situations where they are liable to make this mistake.
One way to do this is to limp preflop, rather than raise, to create a higher SPR on the flop.
Here I limp the Button with 97s. Raising and limping here are similar EV, and both are fine. If you limp, however, you can engineer a situation where your opponents will make bigger mistakes.
When you limp, you create an SPR on the flop of around 17. If you raised preflop, and were called, then the SPR would be around 11 on the flop.
In this hand, the opponent lead the flop, I raised and he shoved.
At an SPR of 11, his play is probably way too loose. But at an SPR of 17, his mistake is magnified significantly.
In poker, everybody gets the same amount of good and bad situations in the long run, and your edge comes from playing comparable situations better than your opponents.
A mistake that many players make, is to stack off with a hand like this (pair and gutshot), no matter the SPR. The higher the threshold that should be stacked off here, the larger the edge you are gaining over your opponent.
Creating a low Stack to Pot Ratio
In this hand, I decide to 3bet for numerous reasons, one of which being that, by lowering the SPR postflop, some advantages can be gained.
Once the opponent calls, the SPR is now 1.6, rather than 4 if I had called preflop.
This means that to bluff at the pot postflop, I can make very small, very inexpensive bets, which shouldn’t get too many folds; but will get a lot of folds in practice (due to peoples’ tendency towards inelastic ranges).
So, in this situation, I bet flop (1.59bb), turn (4.27bb) and river (15.26bb). This is three bets, but only 1.6 times the size of the pot, on the flop, in total.
Hands such as a 5 or Ace high should be strongly considering calling down here, due, in part, to such a low SPR on the flop.
However, in practice, many opponents see a 3bet preflop, and three bets postflop, and therefore see 5x or ace-high as worthless here.
Stack to Pot Ratio Conclusion
Becoming aware of the Stack to Pot Ratio (SPR) while you play, is very important, and can lead to you finding many additional ways to exploit your opponents.
Hopefully the two examples shown here will give you food for thought when playing your next session, as you engineer pot sizes to your advantage.