Definition
Plain language
In poker, holding a card the opponent would need for a strong hand, which makes it less likely they have that hand.
As stated in the literature
A card in your own holding that removes combinations of the opponent's strong hands from consideration (e.g., holding an ace lowers the chance they hold pocket aces); used in PokerSkill's river guidance to inform bluffing and value decisions.
Also called: blockers
Why it matters: It lets a player reason about what the opponent can't be holding, turning their own cards into clues that sharpen bluffing and calling decisions.
For example, if you hold the ace of spades, it's impossible for your opponent to have the nut flush that needs that exact card, so you can bluff more confidently.
Heard on the show
“Another tests calcium-channel blockers, finds no metformin interaction, and that branch gets pruned — a dead end, dropped.”Episode 187 — An 8-Billion Agent That Beats Models 80 Times Its Size By Looking Things Up