If you need certain cards to improve your hand but you’re facing a bet, is it worth calling? Some quick math tells you.
There’s 60 in the pot and you face a bet of 20. Any card that improves your hand is an “out”.
What are your chances of hitting one of your outs? After the flop, multiply your outs by 4. After the turn, by 2.
15 × 4 = 60%
Pot + your call = pot total. Your call ÷ pot total × 100 = the cost of calling.
60 + 20 = 80 · 20 ÷ 80 = 25%
Call
Your chance is bigger than the cost
The rule of 4 and 2 is a quick estimate, a little generous when you have lots of outs, but close enough to make good decisions at the table.