SB 4Bet

SB 4Bet in Poker

SB 4Bet refers to the action where the player in the small blind (SB) makes the fourth bet in a betting round—specifically a re-raise after an initial raise and a subsequent 3-bet. This term is most commonly used in no-limit hold'em cash games and tournaments.

Context and Meaning

In a typical preflop scenario, the action might unfold as follows:

• A player opens (raise) from early position.
• Another player in later position 3-bets (re-raises).
• The small blind then 4-bets (re-re-raises).

This sequence is powerful because the small blind is acting after two players have already shown strength. The SB 4Bet usually indicates a very strong range, often including premium hands like AA, KK, QQ, AKs, and sometimes AKo or high suited connectors as bluffs, depending on opponent tendencies.

Strategic Considerations

• Position: The SB is out of position postflop, which makes a 4-bet a commitment to play a large pot without positional advantage. Therefore, the SB’s 4-betting range is typically tighter than a 4-bet from the button or cutoff.
• Stack Sizes: Effective stack sizes matter. With deep stacks, SB might 4-bet a wider range to apply pressure; with short stacks, the 4-bet often becomes a shove (all-in) to avoid difficult postflop decisions.
• Opponent Profiles: Against aggressive 3-bettors, SB can expand their 4-bet bluff range (e.g., with Ax suited or small pairs). Against tight opponents, SB should polarize to value hands and occasional bluffs.
• Frequencies: In modern game theory optimal (GTO) play, the SB 4-bet frequency is low—typically around 5-10% of the time facing a 3-bet. Overly frequent 4-betting from the small blind can be exploited by opponents who call or 5-bet bluff.

Example Hand

Example for illustration:

• Blinds: 100/200, 20 ante.
• UTG: raises to 500.
• CO: 3-bets to 1,500.
• SB: 4-bets to 4,000 with K♠K♣, intending to get value from worse hands or fold out weaker 3-bets.

Related Terms

• 3-Bet: The initial re-raise; the SB 4Bet is a response to a 3-bet.
• 5-Bet: A further raise after the 4-bet; sometimes the SB faces a 5-bet shove.
• Cold 4-Bet: A 4-bet made by a player who has not put any money in the pot yet; SB 4Bet is typically a cold 4-bet if the SB did not limp or call.
• Defending the Blind: A broader concept where the SB raises or calls to protect their blind; 4-betting is an aggressive form of defense.

Common Mistakes

• 4-Betting Too Often: Because SB is out of position, frequent 4-bets can be costly when called.
• Incorrect Sizing: A small 4-bet (e.g., min-raise) gives opponents good odds to call; a large bet (e.g., pot-sized) narrows the SB's range too much. Standard sizing is 2.2–2.8x the 3-bet size.
• Ignoring Table Dynamics: The SB’s range should adjust based on whether the 3-bettor is tight or loose, and how often the initial raiser folds.

In summary, the SB 4Bet is a strong, but carefully deployed, move in poker. It signals a hand that wants to play a large pot or to steal the blinds, but it carries increased risk due to positional disadvantage.