blinds

The blinds are SB (small blind) and BB (big blind), with forced preflop bets of 0.5bb and 1bb respectively. Both blinds act before all other players preflop (except after a limp/raise has acted), and postflop they are always OOP.

Detailed Explanation

Two shared traits of blind seats:

1. Forced investment: each hand starts with chips already committed, so the marginal cost of calling is low
2. Absolute OOP postflop: no positional player acts after you

But SB and BB strategies differ sharply:

SB

• After everyone folds to you, vs BB: use a mixed raise + limp strategy
• Facing an open: usually 3bet or fold (flatting out of position postflop is very poor)
• SB is the lowest-win-rate seat of all six positions (even pros typically run -10 to -15 bb/100 here)

BB

• Facing an open, you've already put in 1bb, so you can defend wide thanks to pot odds
• Defending against a BTN 2.5x open: range can be 40-50% wide
• OOP postflop but balanced through check-raises and a sensible check-call range
• BB has a negative win rate (around -20 bb/100), but far better than a "fold all" baseline

Common Use Cases

• SB facing an open: widen the 3bet range, narrow the flat range (only the strongest speculative hands)
• BB defending wide: use pot odds to call, use check-raises to counter
• Blind-vs-blind: SB vs BB is one of the most heavily studied frontiers of modern theory, with dense mixed strategies
• Beginner mistake: flatting too much from the blinds → equity realization plummets postflop OOP — switch to 3bet or fold