The fourbet is one of the most powerful and stylistically defining tools in no-limit hold’em. Used properly, it allows an aggressive player to seize initiative, punish wide three-betting ranges, protect vulnerable hands, and construct sophisticated bluff frequencies that keep opponents guessing. Yet it is also an action that demands careful thought: a poorly chosen fourbet can commit you to difficult spots or leak chips against savvy opponents. This article breaks down the anatomy of the fourbet — why and when to employ it, how to size it, how ranges and stack sizes affect decisions, and how to plan for the postflop when you get called or shoved.
Definition and fundamental reasons for fourbetting: A fourbet is the re-raise of a three-bet (the original raise is the open, the re-raise is the three-bet, and the next re-raise is the fourbet). There are two primary motives for fourbetting: value and fold equity. A value fourbet is made with extremely strong hands that are willing to get stacks in or build a large pot preflop. A bluff or polarizing fourbet is designed to make opponents fold marginal or speculative hands and to balance your strong range so that your opponents cannot exploit you by folding too frequently to fourbets.
Position and range dynamics: Position matters greatly. Fourbetting from late position against an opener who is out of position gives you leverage if called. Conversely, fourbetting from the blinds can be riskier because you might face callers in position on later streets. Your fourbet ranges should reflect positional realities: value-heavy and somewhat narrower in the blinds or out of position, and more balanced and wider when you can profit from position postflop. Against aggressive three-bettors, you should tighten your fourbet bluffs and focus on value; against passive or frequently c-betting opponents, you can expand your bluff frequency.
Sizing for effectiveness: Effective fourbet sizing accomplishes two goals — it sets up convenient postflop decisions when called, and it extracts fold equity against marginal hands. Common practical sizes are in the range of 2.2x to 3.5x the opponent’s three-bet, but absolute figures depend on effective stacks and table dynamics. If the standard open is 2.5x and a three-bet arrives to 7.5x, a typical fourbet to around 20x (or about 2.5-3x the three-bet) is common. Against extremely wide three-bets, larger fourbets can push more hands off equity; against tight ranges, a smaller fourbet may keep the field in and allow you to realize equity. Always think in terms of effective stack percentages: fourbet shove becomes more attractive as stacks shrink relative to the bet sizes.
Stack sizes and commitment lines: Effective stacks greatly influence whether a fourbet should be a shove, a sizing aiming to fold out opponents, or a value-oriented sized bet. With deep stacks, a fourbet bluff has better implied postflop play and can be more complex, allowing for continuation ranges that profit from future folds and fold equity. With medium stacks (20-40 big blinds), fourbet shoves are common as a polarized move, forcing opponents to commit with only very strong holdings. Very shallow stacks generally remove the nuanced strategic elements and reduce the decision to shove or call.
Constructing balanced ranges: Modern high-level play emphasizes balancing your fourbet range to avoid being overly exploitable. That means mixing in some bluffs with your value hands so that opponents cannot automatically fold when they perceive weakness. Typical fourbet bluffs include hands with blockers (such as A5s, A2s, KQs), hands that perform well in all-in equity with fold equity potential, and hands that can navigate certain postflop situations. Value range should include premium pairs and broadway combinations that expect to be ahead when called.
Blocker theory and choosing bluffs: Blockers are essential in constructing effective fourbet bluffs. An ace or king in your hand reduces the likelihood that opponents hold premium hands containing those ranks, making a fourbet bluff more credible. For instance, A5s or A2s serve double duty: they block heavy parts of your opponent’s calling range while maintaining reasonable equity if called and good playability postflop. Choosing bluffs with both blocker value and reasonable showdown equity improves the profitability of fourbet bluffs.
Exploiting opponents’ tendencies: The optimal fourbet strategy depends on your opponents. Against opponents who fold too much to fourbets, increase your bluff frequency and apply pressure. Against players who call too wide, tighten up your bluffs and focus on value hands. Versus opponents who shove light over fourbets, avoid fourbetting without a willingness to get it in; these players exploit fourbets by turning them into frequent shoves. Adjust your frequencies and hand selection dynamically — table history and recent hands often dictate immediate deviations from your default strategy.
Postflop planning and contingencies: Every fourbet must include a plan for postflop play. If you fourbet and get called, what will you do on different board textures? Value-heavy ranges can often continue on favorable boards and control pot size on dry boards, while bluff-heavy ranges may need to c-bet selectively to leverage fold equity. When you face resistance (a five-bet shove or large turn action), know which hands you can continue with and which are forced folds. Preparing these contingencies prevents emotionally driven mistakes in high-pressure spots.
Practical examples: Suppose you face an open from the cutoff, a three-bet from the button, and you are in the small blind. If your stack is deep and you hold KQs, a fourbet as a fold-equity-oriented play makes sense because the hand blocks many strong broadway combinations and plays well postflop. Against a loose-aggressive opener and a passive three-bettor, a polarized fourbet with AA, KK, and select bluffs will pressure the field. In contrast, with 30bb effective stacks, your fourbet range becomes narrower and often commits you directly to a shove or a very polarized size.
Training and frequency: Use solvers as a study tool but remember to adapt. Solvers provide equilibrium ranges that are informative, especially about how often to fourbet in different positions and stack sizes, but real-game exploitative play often departs from equilibrium. Practice fourbetting in lower-stakes environments to observe responses and refine sizings. Track your outcomes and review hands where fourbets were either folded or called — those hands reveal patterns opponents use to counter you and show where adjustments are required.
Final advice: The fourbet is a high-variance weapon that rewards study, timing, and psychological acuity. Balance your fourbet ranges, use blockers intelligently, consider stack depth and positional leverage, and always enter a hand with a clear postflop plan. Flexibility is key: shift between exploitative and balanced approaches according to table dynamics and player tendencies. With disciplined practice and thoughtful adjustments, your fourbet strategy can become a major source of edge at both live and online tables.