Heads-Up Preflop Raise Sizing War Strategies in Heads-up Play Owen Gaines Owen Gaines is a professional poker player and author who has played an estimated ten million hands and written four poker strategy books. June 2, 2026 Small sizing changes can decide who controls heads-up preflop pressure Heads-up poker creates more preflop raising than any full-ring or six-max format because both players are forced into blind positions every hand. The button acts first before the flop but last after the flop, which makes raise sizing a major strategic lever. A player who raises too small gives the big blind easy calls. A player who raises too large risks building pots with weak hands. The standard opening range from the button is wide, but size should still reflect stack depth, rake, opponent tendencies and post-flop edge. At deeper stacks, a 2x or 2.25x raise keeps the pot manageable and preserves room to play turns and rivers. Against a passive big blind, a slightly larger open can extract more value from hands that dominate their calling range. The raise sizing war begins when the big blind starts three-betting often. The button should not answer every three-bet with aggression. Strong hands can four-bet for value, while selected blockers such as suited aces can work as bluffs. Medium hands often perform better as calls, especially when they retain playability after the flop. Against large three-bets, the button must defend less often because the price worsens. Against smaller three-bets, more hands can continue. That difference matters. Calling too wide against big sizing burns chips. Folding too much against small sizing lets the big blind profit immediately. The best adjustment is not emotional retaliation. Instead, it’s range discipline. Track frequency, not just one hand. If the opponent three-bets too often, widen value four-bets and add blocker bluffs. If they three-bet tight, fold more marginal opens and stop paying them off.