Cutoff CO Opening Range Guide: How to Leverage Positional Advantage to Build a Profitable Range

Importance and Range Principles of the Cutoff

The Cutoff (CO) is located to the right of the Button (BTN) and is one of the last positions to act preflop. With only the BTN and blinds left to act, the CO has a significant postflop positional advantage—you get to see other players' actions before making decisions after the flop. Therefore, the CO's opening range should be much wider than early position (EP), but slightly tighter than the BTN.

Standard Opening Range Example

Below is a typical full CO range (assuming 6-max, 100BB effective stacks, no special dynamics):

• Strong hands (3bet+ value): JJ+, AK, AQs+ – roughly 6% of hands. These are usually raised for value and prepared to resist 3bets.
• Medium hands (raise open): ATo+, KQo+, A9s+, KTs+, QJs+, JTs, T9s, 22+ – about 20% of hands. These have sufficient equity or playability and are suitable for direct raises.
• Steal hands (raise or fold): A2s-A5s, K9s-KJs, Q9s-QTs, J9s, T8s+, 98s, 87s, 76s, 66-77, A7o-A9o – roughly 10% of hands. These aim to steal blinds or use positional advantage postflop.

Overall, a balanced CO opening range is about the top 30% of hands. Adjust accordingly in actual play.

Key Factors Affecting CO Range

1. Opponent Style

• Tight-passive blinds: Broaden your stealing range, increasing raise frequency with small pairs, suited connectors, and weak aces.
• Loose-aggressive blinds or BTN: Tighten your range to avoid frequent 3bets or getting into tough spots postflop. Prioritize raising with big hands and suited connectors.

2. Stack Depth

• Short stacks (<30BB): Narrow range to strong hands (TT+, AQ+) due to limited postflop maneuverability.
• Deep stacks (>150BB): Expand to 35%-40%, including more speculative hands (e.g., small suited connectors, weak aces), leveraging implied odds and positional advantage.

3. Table Dynamics

• Blinds folding frequently: Increase stealing frequency, even raising with hands that only have backdoor draws.
• BTN is a 3bet heavy: Reduce marginal hand raises; prefer calling or folding with medium hands.

Execution Strategy and Postflop Plans

Preflop Decisions

• Raise sizing: Standard 3BB; reduce to 2.5BB when stealing to save chips; increase to 4BB against weak blinds to isolate.
• Responding to 3bets:
  • Defense frequency: Against BTN 3bets, defend roughly 40% (including 4bets and calls).
  • 4bet range: QQ+, AK for value; A2s-A5s as bluffs (for balance).
  • Calling range: AJs, ATs, KQo, 99-JJ, suited connectors (e.g., T9s, 98s).

Postflop Considerations

• As the preflop raiser, c-bet frequency on the flop is typically 60%-70%. On dry boards (e.g., K72r), bet small (1/3 pot); on wet boards (e.g., T98 two-tone), bet large (2/3 pot) or check.
• Bet aggressively when the flop favors your range (e.g., high cards or draws); check more when the board favors opponents' ranges.
• Use position for thin value bets and bluffs, especially capitalizing on opponents' fold equity.

Common Mistakes

• Overly wide opening: Failing to adjust for players behind, leading to frequent 3bets and chip loss.
• Inflexible postflop play: The CO is not obligated to c-bet; checking for pot control can be superior.
• Ignoring ICM: In tournaments near the money, significantly tighten the CO range to protect chips.

In summary, the CO opening range must balance "steal equity" with "cost of being 3bet." Adjust continuously based on actual situations and refine by observing opponents' reactions.