Cutoff CO Open-Range Guide: Positional Advantage and Practical Adjustments

What is the Cutoff (CO)?

The cutoff is the first position to the right of the Button, i.e., the 4th position in a 6-max table (UTG, HJ, CO, BTN, SB, BB). In a full-ring table (9-10 players), CO is after HJ and before BTN. CO is one of the last positions to act preflop with position (only behind BTN), so it can steal blinds more safely and leverage position to control the pot postflop.

Basic CO Opening Range

Assuming an effective stack depth of 100BB with no special reads on opponents, a reasonable CO opening range is about 15%-25% of starting hands. Here is a typical range example (around 20%):

• Pairs: All pairs (22+)
• Big cards: A2s+ (suited aces), AKo-AJo, KQo, KJs+, QJs, JTs
• Suited connectors: T9s, 98s, 87s, 76s, 65s (some players include lower suited connectors)
• Offsuit broadways: ATo, KJo, QJo (some ranges)

Strictly speaking, CO can open wider than HJ because BTN, SB, and BB are yet to act, but BTN has position, so caution is needed.

Typical ~20% range example (by percentage):

• 22+ (all pairs, ~6%)
• A2s+ (12 suited aces, ~2.3%)
• ATo+ (ATo, AJo, AQo, AKo – 4 combos, ~3%)
• KQs, KJs, KTs (suited K with Q/J/T, ~0.9%)
• QJs, JTs (~0.6%)
• T9s, 98s (~0.6%)
• A9s, A8s, A7s, A6s, A5s, A4s, A3s (partially included, ~1.5%)
• KQo (~0.9%)
• Plus other mixed hands.

Actual range should be adjusted based on opponents.

Factors Influencing CO Opening Range

1. Opponent Type

• Nit/Tight-Passive: Widen range, steal blinds more, especially against SB and BB. Add low pairs, suited connectors, Axs, etc.
• LAG (Loose-Aggressive): Tighten range to avoid being 3-bet squeezed. Prefer strong hands (JJ+, AQ+) and a few hands with potential to fight back (e.g., A5s).
• Calling station: Value-oriented, open strong hands (TT+, AJ+), reduce bluffing hands because calling stations call a lot.

2. Blind Players

• If SB and BB are tight with high fold rates, widen range significantly (e.g., 28%+).
• If SB and BB are loose-aggressive and 3-bet frequently, tighten range and consider 4-betting or calling to defend.

3. Stack Depth

• Deep stacks (>150BB): Add more speculative hands like small suited connectors (54s+) due to high implied odds.
• Short stacks (<40BB): Narrow range, mainly strong hands (TT+, AQ+) to push all-in or open.

4. Dynamic Adjustments

• If there are multiple limpers ahead, generally avoid limping; instead raise to isolate, but consider a wider range to isolate in CO.
• If BTN is an aggressive player, tighten CO's opening range to avoid being 3-bet by BTN and facing tough decisions.

Key Postflop Strategy Points

• Use Position: CO acts second-to-last postflop (only BTN acts later), but still has positional advantage. Continuation bet (C-bet) frequency can be high, especially on dry boards.
• Blind Stealing and Protection: When blinds call, CO should usually continuation bet postflop, especially when the board connects with your range.
• Against BTN: If CO opens and BTN calls, BTN has position, so CO should be more cautious postflop. Generally, a leading range should lean toward value.
• Isolating Limpers: When someone limps ahead, CO can raise to isolate with a wider range, e.g., A8s+, KTs+, 77+.

Example Range Chart (10% / 15% / 20% Comparison)

(Note: Combos vary by hand type)

Summary

The CO position is one of the most important stealing positions preflop. Its opening range should comprehensively consider positional advantage, opponent tendencies, stack depth, and dynamics. Generally, the basic range is between 15%-25%. Against tight-passive blinds, you can be more aggressive in stealing, while against aggressive opponents, you need to tighten up. Postflop, you should leverage position to make continuation bets and be aware of BTN's counterattacks. By continuously adjusting your CO range, you can significantly increase your win rate.