SPR (Stack to Pot Ratio)

The stack-to-pot ratio is defined as the ratio of your stack in relation to the pot. Also, the SPR is an indicator of your risk/reward ratio.
The pot is $20 and you have $80 left. Your SPR is therefore: $80/$20 = 4.
The higher the SPR, the more can you still win or lose from the pot. The SPR is also helpful when evaluating your playing style: for instance, the higher your SPR, the more profitably can you play your draws.