Okay this seems to be a topic that has had enough coverage lately, but I still struggle with picking my exact range for hands to defend in the bb, so I decided to make a topic and hope you guys can help me out a bit. Math is probably the weaker side of my game, so don't be too harsh on me;)

Blinds are 5/10 in a cash game and we are super short stacked. I'm in the bb with 5 big blinds and the button opens 41%. It's clear we need to call 10$ to participate in a 45$ pot, so 10$/45$ x 100% = 22.22%, so we should be defending really really wide here, but the question remains, how wide? The chance of one of your hole cards making a pair on the flop is 32.43%, I got this off the internet, how do I calculate this myself?

So from the example I give, it seems that you can defend any two cards you get in the bb. Just call pre and donk any pair, fd, gutshot for the remaining 3 bb's you have left. We need 30$/105$ x 100% = 28,57%

Not sure if I made myself clear, but hopefully you guys can help me anyway! I'll end with an example:

BTN: $661 (66.1 bb)

SB: $139.50 (14 bb)

Hero (BB): $50 (5 bb)

CO: $90.50 (9.1 bb)



Preflop: Hero is BB with 8 T

CO folds, BTN raises to $20, SB folds, Hero calls $10



Flop: ($45) 3 T J (2 players)

Hero bets $30 and is all-in, BTN calls $30



Turn: ($105) 6 (2 players, 1 is all-in)

River: ($105) 2 (2 players, 1 is all-in)