CO 3Bet

Definition and Context

In poker, specifically in No-Limit Hold'em, the term "CO 3Bet" refers to a re-raise (the third bet in the betting round) made by the player sitting in the cutoff (CO) position. The cutoff is the seat immediately to the right of the button (dealer). A 3Bet occurs when a player raises after an initial raise (the open raise) has been made. Thus, a CO 3Bet is a re-raise from the cutoff. This is a common preflop action because the cutoff has positional advantage over the blinds and often over the initial raiser (if the raiser is not the button).

Strategic Importance

The cutoff is a strong position for 3-betting because it allows the CO player to isolate the initial raiser while still having position on most opponents postflop (except the button). A CO 3Bet can serve multiple purposes:

• Value: With strong hands like AA, KK, AK, QQ, the CO 3Bet aims to build a pot while in position.
• Bluff/Semi-bluff: With hands that have good playability (e.g., suited connectors, small pairs), the CO may 3Bet to force folds from weaker hands or take down the pot immediately.
• Range Advantage: The CO can apply pressure to the initial raiser, especially if the raiser is from middle or late position, since the CO's 3-betting range can be wider than earlier positions.

Typical Range Considerations

A typical CO 3Bet range might include:

• Premium hands: AA, KK, QQ, AK (often for value).
• Strong hands: JJ, TT, AQ, AJs (sometimes mixed with calls).
• Bluff hands: Suited connectors like 76s, 87s, A2s-A5s, or small pairs (22-66) as semi-bluffs.

The exact range depends on the opponent's tendencies, stack sizes, and table dynamics. Against a tight opener, the CO may 3Bet a narrower value range; against a loose opener, the CO can widen both value and bluff ranges.

Common Villain Responses

When facing a CO 3Bet, the original raiser may:

• Fold: If holding a weak or marginal hand.
• Call: With medium-strength hands or speculative hands, planning to play postflop in position (if the caller is the button) or out of position (if the caller is in early or middle position).
• 4-Bet: With very strong hands (or occasionally as a bluff) to re-raise the CO. The CO then must decide whether to call, fold, or 5-bet.

Example Scenario

Blinds 1/2, 6-handed. UTG folds, UTG+1 raises to 6. Hero in the cutoff holds A♠K♠. Hero 3-bets to 18. This is a CO 3Bet for value, aiming to isolate UTG+1 and build a pot in position. If UTG+1 folds, Hero wins the blinds and the raise. If UTG+1 calls, Hero has a strong hand with position postflop.

Conclusion

The CO 3Bet is a versatile and powerful weapon in a player's preflop arsenal. It leverages positional advantage and can be used both for value and as a bluff. Understanding when and with what hands to 3-bet from the cutoff is a key skill in modern poker strategy.