betting
Four-bet (4-bet)
Also: 4-bet, 4bet, five-bet
A re-raise of a three-bet. Four-bet pots are large and usually decided pre-flop or on the flop; the range doing it is the tightest in the game, plus a few bluffs with ace blockers.
Example. Open 2.5 bb, 3-bet to 8 bb, 4-bet to 20 bb — the original raiser has 4-bet.
With 100 big blinds, a 4-bet is typically to about 2.2–2.5 times the 3-bet, leaving room for a 5-bet all-in. Value 4-bets are pocket aces, kings, queens and ace-king; bluff 4-bets are hands like A-4 suited that block aces and can fold to a shove without much regret. Beyond the 4-bet, players talk about a 5-bet (usually a shove) and, very rarely, a 6-bet.