BB 4Bet

Overview

BB 4Bet refers to a re-raise (the fourth bet) made from the Big Blind position after an opening raise and a 3bet have already been made. This action usually occurs in heads-up or multi-way pots where the Big Blind faces aggression from later positions. The Big Blind's range for 4betting is typically polarized: strong hands like AA, KK, AKs, and sometimes bluffs. The decision to 4bet from the Big Blind depends on stack depths, opponent tendencies, and the size of the 3bet.

Strategic Considerations

Positional Disadvantage

Being out of position postflop, the Big Blind often prefers 4betting as a means to end the hand preflop or to create a situation where they can better realize equity. A larger 4bet size (often 2.2–2.5x the 3bet) is common to deny correct odds for the caller. However, overly large 4bets can commit too many chips, especially with medium stacks.

Range Construction

A standard BB 4bet range includes value hands (QQ+ and AK) and occasionally suited connectors or Axs as bluffs. The frequency of bluffing increases when the opponent has a wide 3bet range (e.g., from the button or cutoff). Against tight 3bettors, the Big Blind should tighten their 4bet range. Solvers often mix calls and 4bets with borderline hands like AJs or TT depending on opponent's range.

Stack Depth Effects

• Deep stacks (100bb+): The Big Blind can 4bet more liberally, including some bluffs, because implied odds allow for postflop play.
• Shallow stacks (below 40bb): The Big Blind may prefer to shove all-in rather than make a smaller 4bet, as committing a large portion of stack with a non-all-in bet is often suboptimal.
• Short stacks (20bb or less): The Big Blind's 4bet is effectively a jam, and their range should be value-heavy.

Example Scenario

Assume a 6-max game, 100bb effective stacks. UTG opens to 3bb, cutoff 3bets to 9bb, hero in BB. A typical BB 4bet range might be {AA, KK, AKs, AKo, A5s, A4s, KQs} as bluffs. The 4bet size could be 22bb to 24bb. If the cutoff shoves, hero will call with AA/KK, and sometimes AKs if suited. Bluffs will fold. This range exploits a cutoff 3bet range that includes many suited connectors and broadways.

Risks and Adjustments

Overusing BB 4bet bluffs can be costly, as the Big Blind will often be forced to fold to a 5bet shove. Opponents may adjust by 5betting lighter or flatting 4bets more often. To counter this, the Big Blind should occasionally call 3bets with strong hands (e.g., QQ, AK) to balance their range. Understanding opponent's 3bet and 5bet tendencies is crucial.

Conclusion

BB 4Bet is a powerful tool for the Big Blind to defend against aggressive 3bets, but it requires careful range construction and awareness of stack sizes. It shifts the pressure back to the original raiser and can prevent the Big Blind from being exploited postflop. Mastery of BB 4bet ranges is a key skill in modern no-limit hold'em.