Here's one I learned reading The Grinders Manual.
we can compute our "
Required Fold Equity" (RFE) when we open with a raise, using the following formula:
RFE = R/(R+PG), where R = our raise size and PG = our potential gain.
Let's say we're playing 6-max cash, it folds to us on the button and we decide to open-raise to 2x the big blind... so R is 2 big blinds, and PG is the sum of the SB + BB, or 1.5 big blinds... this makes our RFE = 2/3.5, or 57%.
In other words, we need to obtain folds from both SB and BB 57% of the time we make this play in order to "break even". If they fold more often than that, we profit in the long run by making this raise, and please notice, it does not matter what our two cards are here at all.
So... how do we know if this is a good play or not? Quite easily - we look at each players specific stat called "Fold to BTN Raise", and since we need both players to fold in order to win this pot uncontested, it is an "AND" condition, meaning we multiply their stats together.
If SB folds 85% of the time to a BTN raise and BB folds 70%, multiplying them together (0.85 * 0.70) we get 0.60 or 60%... and since our RFE is only 57%, this becomes a "+EV" play for us - it is a play with positive
expected value, and thus it is a profitable play.
If you experiment with the math, you will quickly realize raising to 3x results in a higher RFE, which essentially explains why 2x opens have become the standard in the modern game as opposed to a 3x open, which used to be the norm years ago. It's all because of fold
equity considerations. It is counterintuitive, in a sense - most players would think raising more would be better, but this math explains why it isn't. If 2x can get the job done, there's no need to "bloat the pot" with a 3x open, which only makes our task harder, especially when we do get called or raised... since we most likely have a junk hand, we're just throwing chips away with the larger raise size.
Hope this helps someone! It has helped me to understand the power of the HUD and how we can utilize it more to our advantage.
