Fold around to the blinds and you reach poker's purest confrontation: two players, everyone else gone, ranges known to both. Blind-versus-blind spots are the widest in the game and the most asymmetric — the small blind holds preflop initiative but signs away POSTFLOP position the moment the big blind calls. Every lesson about wide ranges and poor realization meets its opposite number here.

The widths, read live from this app's charts: the small blind opens 42% of hands for 3bb (rfi:SB) — wider than any full-table seat, because only one opponent remains to get through. The big blind answers by defending 51% (vsrfi:BB:vs:SB), 3-betting 13% and flatting the rest. Both numbers dwarf their full-table counterparts, and neither is a typo: with the button gone, there's no third player to punish loose opens or loose defends, so BOTH sides expand until they meet.

The strategic texture differs from every other matchup. The small blind's raises fold out the middle and isolate a near-random single hand — but the times the big blind continues, the small blind plays EVERY street first, with a capped calling range staring back across the table. That inversion explains the chart's structure: the small blind 3-bets-or-folds much of what would be a flat elsewhere (position is worth that much), while the big blind flats MORE than it raises, happily realizing its positional edge with medium hands. Watch the same matchup at ten big blinds and the tree collapses again — the small blind's chart becomes jam-or-fold like every push/fold seat, jamming 56% (pf:10:jam:SB).

One practical warning closes the loop: these are the widest ranges you'll grade against, which makes them the easiest place to over-adjust on tiny samples. A few blind-versus- blind losses feel systematic because the pots arrive unraised into familiarity — but the charts say the width IS the equilibrium, and drifting tighter to "avoid trouble" quietly surrenders the widest edge the format offers.