Full explanation — Small Blind (SB)
The Small Blind (SB) is a mandatory bet posted by the player immediately to the left of the dealer button, typically equal to half the big blind. The SB is widely considered the toughest position at the table: it acts first in every betting round after the flop, meaning it has the least information relative to everyone else once preflop is over, which makes it structurally disadvantaged for the rest of the hand.