Poker Math That Matters

Semi-bluffing
Semi-bluffing is a powerful tool in poker. It's important to learn
when to use it and how to use it correctly. Bluffing and semibluffing
bring us into the world of fold equity. Fold equity is a
term we use to describe what we gain when our opponent folds.
Our opponent can only fold after we've shown aggression by
either betting or raising. Fold equity gives us more than one way
to win a pot. We can make the best hand, or our opponent can
fold. In the previous section, I talked about bluffing. We
learned how to think about the reward to risk ratio. Our
examples were on the river where we always had the worst hand.
Now, as we explore the power of fold equity, we're going to look
at the more complicated semi-bluffing. Semi-bluffing is when
you're betting with a hand you doubt is good right now but has a
good chance to improve on a later street. Because of this, you
cannot semi-bluff on the river. Let's begin by looking at an
example.
We have a 100x stack and hold A♦Q♦ on the button in a 100NL
game. An early position player limps, and we raise to $4. The
big blind started with $40 and calls. The limper folds. The flop
is 7♦9♦3♥. The pot is $9. The big blind has $36 left. We decide
to bet $9, and he calls. The pot is now $27, and the big blind has
$27 left. The turn is the K♣. The big blind bets out for $12.
As we examine our pot odds, we can see he bet just under 1/2
pot, which means we're getting a little better than 3:1 and need to
have greater than about 23% equity to continue in the hand.
Let's make some assumptions about his range to see how we're
doing against that assumed range. I've given you no information
about this player to help you formulate a range, so I'm just going
to give you a range to work with. Let's say we assume his range
to be AK, 88, TT and 89s.
99