AA vs 22: how often do deuces crack aces?

This is the surprise in every pair-versus-pair table: deuces do roughly as well against aces as kings do. The underdog pair wins mainly by flopping a set, and a deuce hits the board exactly as often as a king does. The deuces even sneak in a few extra wins by making straights on low boards where the aces play only one pair. The lesson is that against a bigger pair, the rank of your pair barely matters. What matters is set mining cheaply: deuces want to see a flop for a small price and win a big pot the one time in eight they spike.

Quick tip: Small pairs do not want all-ins preflop, they want cheap flops. Two outs twice is about 18% when you miss, so the money comes from sets, not showdowns.

All numbers are all-in preflop equity vs one opponent, computed by the Poker Shark equity engine from the full 169 by 169 hand matrix, weighted across suited and offsuit combos.