SPR, which stands for "stack-to-pot ratio," shows how big a player's stack is in relation to the pot.
To figure out SPR, you need to divide the size of the smallest stack in the hand by the size of the pot. For example, let’s assume you are playing a tournament and find yourself on the flop with10,000 in the middle of the pot and 25,000 behind you. In this situation, you need to divide 25,000 / 10,000 and get a stack to pot ratio of 2,5.
Usually, SPR is divided into three groups –from 0 to 3 is low SPR, 3 to 6 is medium, and over 6 is considered a high stack top pot ratio. SPR can be calculated on any street in the hand.
Going back to our example, 2,5 would be characterized as a low stack to pot ratio, meaning you should play your hand aggressively if you decide to get involved and will probably be forced to commit a big junk of your stack.
Lower SPR also means that your hand strength goes up in value. If you have top pair with low SPR, you will be very happy to play for stacks, while the same hand in a high SPR situation will be significantly weaker. Therefore understanding this concept can be very valuable for sport stack spots.