Part: Part Five - Betting Before the Flop
A cold four-bet bluff
Pre-flop
An under-the-gun player opens, an aggressive cutoff three-bets, and it folds to you in the big blind with A♠5♠.
Open, then an aggressive three-bet, and you hold A♠5♠. Best?
WhyThe cutoff is three-betting aggressively and light, and the ace in your hand removes a big chunk of the A-A and A-K he'd need to continue against a four-bet. That blocker is what makes the play: you represent the top of your range, apply maximum pressure, and keep a suited backup draw the times you are called. Flatting a weak ace out of position is the trap you're avoiding.
What happensThis time the three-bettor actually has it and five-bet jams; you release, down the four-bet. Don't flinch - the blocker made this a profitable bluff over the long run, and it can't get through every time. You lose the pot, not the logic.
An ace-blocker like A-5 suited turns a weak hand into a powerful cold four-bet bluff against an aggressive three-bettor. It won't always work - occasionally he has the goods and you fold - but blocking his premiums is what keeps the play profitable across all the times it does.
The best cold four-bet bluffs hold an ace - blocking A-A and A-K means the aggressor is far less likely to have the hand that plays back, while you credibly represent one yourself.