Cutoff CO Opening Range Detailed: From Tight-Aggressive to GTO Balanced Strategy

Position Scenario Description

The [Cutoff] (CO) is the seat to the left of the button (BTN) and has the second-last action postflop, only behind the button. The CO player sees all actions from earlier positions and can choose to raise or fold before the button acts, giving them high steal and squeeze opportunities. However, since the button is still behind them, the CO's range must balance value and defense.

Recommended Range

Below is the typical opening range for CO in 6-max [Full Ring] cash games when all earlier positions fold (assuming 100BB stacks and no specific reads).

Base Range (approximately 25%-28% of hands)

• Strong Hands: All pairs 77+, all suited connectors ([A2s]+, [K7s]+, [Q8s]+, [J9s]+, [T8s]+, [96s]+, [85s]+, [75s]+, [64s]+), all suited gappers ([A5s]-[A2s], [K9s]-[K6s], [Q9s]-[Q8s], [J8s], [T7s], [97s], [86s], [76s]), all unsuited big cards ([A9o]+, [KQo], [KJo], [QJo]), and some unsuited connectors ([ATo], [AJo], [KQo]).
• Frequency Adjustment: Actual selection can be fine-tuned based on opponents and dynamics.

Visual Range Description

• Pocket Pairs: [22]-[AA] (some players fold 22-[55], but a more balanced strategy usually retains all pairs because of set-mining potential)
• Suited Aces: A2s-[A5s], [A6s]-[A9s], [ATs]+ (usually all included)
• Suited Kings: [K7s]-[K9s], [KTs]+ (low suited kings are sometimes folded, but for balance [K5s]-[K6s] may be raised)
• Suited Queens: Q8s-[Q9s], [QTs]+
• Suited Jacks: [J8s]-[J9s], [JTs]
• Suited Tens: [T7s]-[T8s], [T9s]
• Suited Nines: [96s]-[98s]
• Suited Eights: [85s]-[87s]
• Suited Sevens: [75s]-[76s]
• Suited Sixes: [64s]-[65s]
• Unsuited Big Hands: [A9o]+, KQo, [KJo], [QJo] (sometimes [A8o]-[A6o] but at lower frequency)
• Suited Connectors: All suited connectors ([54s]+), but some players only raise [T9s] and above.

Range Construction Logic

The CO range is built on a balance between "value raises" and "speculative raises".

1. Value: Intends to get immediate value from calls or 3bets. Includes top strong hands ([QQ]+, [AKs]) and medium strong hands ([TT]-[JJ], [AQs], [AKo]).
2. Protection: Uses medium pocket pairs ([88]-[99]) to protect against being outdrawn when they flop an overpair.
3. Speculation: [Suited connectors] and gappers, aiming to hit draws or strong hands postflop and leverage positional advantage.
4. [Blind Steal]: With the button and blinds behind, use some weaker hands (e.g., A9o, KJo) to steal blinds, especially if the blinds are tight.
5. Frequency Control: To avoid being exploited, do not raise only strong hands; raise about 25%-28% of hands to keep fold equity acceptable.

Adjustment Factors

Based on Opponents

• Tight Blinds: Widen stealing range, include more weak unsuited aces and connectors (e.g., [A5o], [K9o], [QTo]).
• Loose Blinds: Tighten range, raise only value hands and good speculative hands ([suited connectors], Axs), and be prepared to defend against 3bets.
• Button Likes to 3bet: Reduce raising frequency, especially with weak hands, and widen your [4-bet range].

Based on Stack Depth

• Short Stack (<50BB): Reduce speculative hands, add more value hands, as implied odds for suited connectors decrease.
• Deep Stack (>200BB): Increase speculative hands and suited connectors, as potential postflop rewards are higher.

Based on Dynamics

• Limps from Early Positions: CO should raise to isolate, with a narrower range (about 15%-18%), excluding weak hands to avoid getting squeezed.
• Raise from Early Positions: CO should use a calling or 3bet range, not a direct raise.

[GTO] Reference

In [GTO] models, the CO opening frequency is about 25%-28%, and the raise size is typically 3BB (at 100BB depth). GTO strategy emphasizes balance:

• About 1/3 of the raising range consists of value hands (intended to continue against 3bets), and 2/3 are speculative or steal hands.
• When facing a 3bet, GTO requires defending about 40%-50% of the raising range (including calls and [4bets]) to prevent opponents from profiting by 3betting any two cards.
• Specific defending frequency depends on 3bet size and opponent tendencies.

Practical Application

Example 1: Standard Situation

A player is in the CO position, all earlier positions fold. [Pocket cards] are 8♠7♠. According to the baseline range, this hand (suited connector) should [raise]. Raise to 3BB, blinds call. Flop is T♠9♠2♦, hitting an open-ended straight draw and a backdoor flush draw. The player makes a half-pot continuation bet, representing hands like JQ, QT in the range, which can force folds.

Example 2: Adjusted Situation

The big blind is an aggressive player who likes to 3-bet. CO holds A♠J♦. According to the baseline range, this should be a raise, but considering the blind will often 3-bet, you should either fold or defend with a wider [4-bet range]. If you decide to raise, you must be prepared to respond to a 3-bet (call or [4-bet]).

Example 3: Position-Based Steal

The big blind is a conservative player. CO holds K♣9♣. You can raise to 3BB to steal. The big blind might fold, or call and then fold on the flop to a low board. If the [big blind 3-bets], K9s is not in the defense range, so fold directly.

In summary, the CO opening range needs to be adjusted flexibly based on opponents, stack depth, and dynamics. Maintaining a balanced, value-oriented range while aggressively attacking from position is key to long-term profitability.

Frequently Asked Questions

Q1: Should the CO raise all pocket pairs?

A: Generally it is recommended to raise all pocket pairs, including low pairs ([22]–[55]). This is because you can flop a set and control the pot in position. However, if the blinds are very aggressive, you may consider folding small pairs (22–55) to avoid frequently facing 3-bets and being forced to fold.

Q2: When facing a limp from an earlier position, what range should the CO use?

A: When facing a limp from an earlier position, the CO should raise to isolate, using a narrower range of about 15%–18% of hands. This includes value hands ([TT]+, AQ+) and some speculative hands (Axs, suited connectors), but exclude weak aces and weak kings. This is because the limper may be trapping.

Q3: How should the CO adjust when facing a 3-bet from the BTN?

A: A 3-bet from the BTN usually indicates a strong range. The CO should defend with a frequency of roughly 40%–50%, 4-betting the top of the range (e.g., [JJ]+, AK) and calling with medium hands (e.g., TT, [AJs], [KQs]). Weak hands (e.g., A9o, QJo) should be folded directly.