What is 4-Bet?

A 4-bet in poker is the fourth wager in a betting sequence: a re-raise made in direct response to a 3-bet. Because it escalates the pot before the flop is even seen, a 4-bet signals either a very strong holding (premium hands like pocket kings, aces or ace-king) or a deliberate bluff designed to fold out a wide 3-betting range. The action counts the initial raise as the first bet, the re-raise as the 3-bet, and the response to that as the 4-bet. In No-Limit Hold'em it is almost always sized as a "raise on a raise," making it one of the most pressure-heavy plays available before the flop. A 4-bet can be for value or a bluff, and skilled players balance both so opponents cannot simply fold everything but the nuts. Worked example: at 1/2 blinds, the button opens to 6, the small blind 3-bets to 20, and the original raiser 4-bets to 55. Facing that, the small blind must call 35 more to win a pot of roughly 76, needing about 32% equity to continue. Against a range built mostly of QQ+ and AK, a hand like AQ is often folded, while KK or better calls or shoves. The common mistake is 4-betting too rarely, letting aggressive opponents 3-bet freely and steal pots uncontested. Balancing a value-heavy 4-betting range with occasional bluffs keeps opponents guessing. Compare with three-bet, continuation-bet, all-in and range-poker.