Cutoff CO Opening Range Guide: Building a High-Profit First-In Raise Strategy

Position Scenario Description

The Cutoff (CO) is the last unacted position with position preflop (only the button remains to act). In a 6-max game, the CO sits after the HJ and before the button; in a full-ring game, the CO sits after MP2. Since the CO has both steal potential (against the small and big blinds) and position advantage (almost always last to act postflop), its opening range is typically wider than early positions, but still needs to account for the button's squeeze threat.

Recommended Range

The CO's raising range is approximately 20-25% of hands (depending on blind opponents' styles). A typical range includes:

• Strong pairs: TT+ (often 99 as well)
• High card combos: AQo+ (AQ suited, AK suited), AJs+ (AJ suited and above), KQs
• Medium pairs: 77-88 (sometimes raised or mixed with traps)
• Suited connectors and gappers: JTs, QTs, KJs, ATs, etc., especially wider suited hands like T9s, 98s
• Some small suited aces: A9s-A2s (adjust based on opponents, avoid frequent 3-bet targets)
• Some small suited kings: K9s-K8s (for range balance)
• Special cases: Occasionally add offsuit high cards like AJo, KQo, but at lower frequency

Range Construction Logic

1. Position advantage maximization: CO is relatively safest among unacted positions, allowing inclusion of more speculative hands (like suited connectors) to exploit postflop position for drawing profitability.
2. Steal and isolation: When blinds defend weakly, widen the range to steal dead money; if blinds are tight-passive, add small pairs and small suited aces.
3. Countering button squeeze: If the button 3-bet frequency is high, tighten the range, reduce weak hands that are easily bluffable (like A9o, KJo), and increase hand quality for entering pots.
4. Balancing value and bluffs: Range includes both value hands (strong pairs, big high cards) and bluff hands (small suited connectors, small suited aces), making it hard for opponents to read.

Adjustment Factors

• Opponent style: Against tight-passive blinds, raise to 3BB and attack with about 30% range; against loose-aggressive blinds, shrink to 18-20% range, increase 3-bet calls and 4-bet frequency.
• Stack depth: Deep stacks (>100BB) allow more small pairs and connectors; shallow stacks (<50BB) should focus on high cards and strong pairs, reduce reliance on implied odds.
• Number of blinds: Heads-up pots allow wider CO raises; multiway pots (e.g., blinds with callers) shift towards nutted hands, reduce speculative hands.
• Tournament/Cash: In tournaments, ICM pressure requires more conservative play, especially near the money bubble, reducing marginal hand raises.

GTO Reference

Theoretically, the CO's GTO opening frequency is about 22-26% (varying with blind defense ranges). A typical GTO range includes:

• Value hands (TT+, AQ+, KQ, etc.)
• Bluff/balance hands (A2s-A5s, T9s, 76s, etc.)
• Mixed hands (88-99, ATs, KJs, etc.)

In real games, deviation is normal: against exploitable opponents, deviate from GTO, e.g., drastically widen range against blinds that fold often, tighten against aggressive opponents.

Practical Application

Example: 6-max table, effective stacks 100BB, blinds 0.5/1, CO position.

• Hole cards: T♠9♠ (suited connector)
• Action: Folded to you. Per recommended range, T9s is in raising range. Raise to 3BB. If blind calls, postflop if you hit a draw (e.g., straight or flush), use position to semi-bluff bet; if only high card, optionally check.

Adjustment tip: If the button is an aggressive 3-bettor who frequently pressures CO raises, consider folding or calling (depending on opponent's 200BB+ depth, can call) with weak suited connectors, but usually prefer folding. Conversely, if the button is tight-passive, continue raising per standard range.

Always remember: The CO's strength lies in position and initiative, but you must flexibly adjust the range based on blind and button reactions, avoiding rigidity.