Big Blind (BB) (BB)

Also known as: Big Blind, BB

The seat that posts a full blind and acts last preflop. The price discount on its forced bet gives it the widest defending range — and "bb" is also the stack unit.

The big blind (BB) sits two seats left of the button and posts a full blind before the cards. Despite being a forced bet, it grants two real advantages preflop:

Last to act preflop: when the action folds or just calls around, the BB closes the betting and can check to see a free flop.
A price discount to continue: because one full blind is already yours in the pot, you are getting pot odds to call a raise — you only need to put in the difference. This is why the BB has the widest defending range of any seat.

Against a single raise, you defend wide rather than fold, because folding surrenders your invested blind plus the dead money. The correct width comes from the raise size, position of the raiser, and how well your hand realizes equity out of position — the full subject of blind defense. In tournaments the big blind ante sweetens the pot further, widening defense even more.

Separately, "bb" is the universal stack unit: a 40bb stack means 40 big blinds deep. Measuring stacks in big blinds (not chips) is how players reason about stack-to-blind ratio, push/fold, and pressure.

Example

Blinds 1/2. The button raises to 5; folds to you in the big blind. You already have 2 in, so you only call 3 more to win a pot of 8 — over 2.6:1, needing ~27% equity. Almost any two cards clear that price, which is why you defend a very wide range here instead of folding. The same J♣7♦ you'd muck UTG is a routine big-blind call.