Cutoff CO Opening Range Guide: How to Maximize the Advantage to the Right of the Button

Why the Cutoff is So Important

The Cutoff (CO) is the position to the right of the Button and is one of the most valuable positions at the table. The CO player has positional advantage postflop (except against the Button) and gets to decide whether to raise before the Button acts. This gives the CO two core abilities:

• Information advantage: The CO can observe the actions of players before them to gauge hand strength.
• Steal opportunity: If everyone before folds, the CO can pressure the blinds, especially when blind players are tight.

Therefore, the CO opening range should be wider than earlier positions but slightly tighter than the Button.

Standard CO Opening Range (100BB deep, no special dynamics)

Below is a typical CO preflop raising range (6-max, from UTG to Button). Note: based on regs without clear leaks; adjust dynamically in practice.

Value Raises (roughly top ~15% of hands)

• High pairs: TT+
• Strong AX: AK, AQ, AJs, ATs
• High card connectors: KQ, KJs, QJs
• Medium-strong pairs: 99, 88 (can be value in some dynamics)

Medium-Strength Raises (roughly middle 20%-30% of hands)

• Small-medium pairs: 77 down to 22 (mainly to flop sets, need deep implied odds)
• Suited connectors: T9s down to 65s (e.g., T9s, 98s, 87s, 76s, 65s)
• AX suited: A2s up to A9s (flush potential + Ace-high value)
• Weak high cards: KJo, QTo, JTo (sometimes raised, but caution against domination)

Bluff Raises (bottom of range)

• A-rag offsuit: A2o, A3o, A4o (steal when blinds are tight)
• Gapped suited connectors: K9s, Q9s, J9s (occasionally, using blocker effect and flush potential)

Typical range example: about 25% of hands (~54 combos out of 216). In lower stakes or against weak blinds, can expand to 30%.

Adjustment Factors

1. Opponent Tendencies

• Tight-passive blinds: If blind fold rate is high (>60%), widen range, add marginal hands like A2o, K9s.
• Loose-aggressive blinds: Tighten range, raise more value hands to avoid tough spots after being 3-bet.
• Aggressive Button: If Button frequently 3-bets, reduce raising frequency with medium-strength hands, increase calling or folding.

2. Stack Depth

• Deep stacks (>150BB): Increase proportion of suited connectors and small pairs for better implied odds.
• Short stacks (<40BB): Tighten range, raise mainly strong hands to avoid tricky postflop spots.

3. Blind Size and Structure

• Large small blind: e.g., 1/2 vs 2/5 blinds – larger relative blinds make steals more valuable; can widen range.
• Ante in play: Better pot odds allow more aggressive stealing; add ~2%-5% more hands.

Practical Considerations

• Avoid over-raising: CO is strong, but don’t raise every time it folds to you. If multiple players limp, be cautious as limp-callers may have strong hands.
• Mix bet sizes: Usually raise to 2.5-3 BB. Use larger size (3-4 BB) against loose blinds, smaller size (2-2.5 BB) against tight blinds to save chips.
• Use blocker effect: e.g., holding A2o blocks AA and AK, reducing opponent’s strong hand probability – good for stealing.

Summary

A successful CO opening range rests on three pillars:

1. Understand positional value: wider than early position, tighter than Button.
2. Dynamic adjustment: flex based on opponents, stacks, blind structure.
3. Balanced range: find equilibrium between value and bluffs to avoid being easily read.

Mastering the CO allows you to pick up risk-free dead money preflop and build advantage for postflop play.