Conventional wisdom says that if the flop SPR is less than some nominal value, you should stack-off more lightly than when you’re deeper stacked. Depending on the source of the advice (e.g., Miller, Splitsuit) the stack-off threshold SPR values can vary widely, but range somewhere between 3 and 6.

Why this range of numbers? Or, more importantly, where does this kind of SPR stack-off threshold recommendation come from?

I don’t have a full answer, but I did recently take the time to plot Expected Value (EV) as a function of SPR vs. Pot Equity:



Note the “knee” in the curve at/around an SPR of 3 to 3.5. I think this explains why some experts cite 3 as the value below which you should be pot committed with single-pair type hands.

It also implies that you should pretty much always be pot committed on flops where you have pot equity of 50% or greater.

I think. Maybe. Hell, I don’t know.

I would love some commentary and feedback on this plot and SPR theory from the real math experts here...

Cheers!