Big blind

Take a $1/$2 game. The button opens to $6, the small blind folds, and you're in the big blind with $2 already in front of you. You need $4 more to call. The pot holds $9 (the button's $6, your $2, and the small blind's dead $1), so you're risking $4 to win $9, better than 2 to 1. That price drags hands into play that would be instant folds anywhere else. 9-7 suited, heads-up against a button open, clears it without trouble. The discount is why the big blind sees flop after flop it would otherwise muck.

Stacks get counted in big blinds ("I'm on 80bb") because that bet is the one everyone at the table has already put up, so it reads the same at any stakes. But the price cuts both ways. Once the small blind folds, you're out of position for the rest of the hand, acting first on every street against a player who acts last. A call that looked cheap before the flop leaks money after it, when the raiser keeps firing and you keep guessing.

What the discount buys matters as much as the discount itself. Suited and connected hands defend best (9-7 suited, 6-5 suited, K-9 suited flop pairs with backup, draws, second ways to win) while offsuit high-card junk turns a cheap call into a guessing game. And the price moves with the open size. Against a min-raise to $4 you're calling $2 with $7 already out there, 3.5-to-1, defend nearly everything playable. Against a $10 open you're calling $8 into $13, not much better than 1.6-to-1, and most of the discount is gone. The top of your range shouldn't call at all: three-betting A-Q or 9-9 takes back the initiative instead of renting a flop out of position.

Some bookkeeping honesty helps too. The big blind loses money long-run in every lineup (every other seat only posts when the button comes around), so the goal isn't profit, it's the smallest loss. Fold everything and you surrender the full $2 every single orbit while late position steals for free; defend sensibly and you claw most of it back. Out of position the plan matters more than the cards: check-raise the flops that favor your range, let go of the ones that don't, and remember the raiser misses the flop about as often as you do.

The usual mistake is defending on price alone. Beginners see the discount and call with J-4 offsuit or Q-6, then have no plan when the flop misses and the bet lands. Getting the right price to call is not the same as holding a hand that can win the pot once the cards are out. The mirror image costs just as much: folding the big blind to every steal because playing out of position feels bad. The $2 left your stack the moment it was posted: the only question is how much of it you take back.