KK vs AK: who wins?

This matchup is all about blockers. The kings hold two of the kings ace-king would love to pair, so the AK is really playing three aces as its outs. That pushes kings well past the usual race numbers without reaching pair-versus-pair territory: call it 2-to-1 and a bit. It is also one of the most common big all-ins in poker, because both hands re-raise relentlessly and neither can imagine folding. If you hold the kings, you are happy every time. One ace in three spoils it, which is exactly the fraction of the time an ace-high flop was going to ruin your night anyway.

Quick tip: Two players re-raising hard preflop usually means exactly this collision or a bigger pair. Kings against AK is the good outcome.

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.