CO Open-Raise Range Guide: How to Maximize Stealing and Pressure Advantages

Positional Scene Explanation

Cut-Off (CO) is the position to the left of the Button, the second-last to act on the table (both 6-max and 9-max). Advantages of the CO:

• You have observed the actions of players in earlier positions (fold or call/raise), giving you relatively sufficient information.
• Postflop, the CO remains in a favorable position (second only to the Button), allowing you to control pot size and bluff.
• When directly facing timid or conservative blind players, you can frequently steal blinds.

Typical scenario: 6-max table, folded to you (CO), blinds are regular players, effective stack ~100BB.

Recommended Range (Hand Types Description)

Assuming 100BB effective stack, no special reads, no significant leaks in blind players, the recommended CO open-raise range (approximately 22%–25% of hands):

• Strong Hands (Value Raises): 22+, A2s+, K9s+, Q9s+, J9s+, T9s+, 98s, 87s, 76s (all pairs, all suited aces, and some suited connectors and suited gappers)
• Medium Hands (Mixed Value and Bluffs): AJo+, KQo, KTo+, QTo+, JTo (these unsuited broadways are mainly used to exploit the blinds' weaker calling ranges)
• Bluff Hands (Range Balance): Some low suited connectors like 65s, 54s (not necessary, but can increase postflop playability)

Specific combos: About 280–300 combos (22%–23% of all 1326 combos). Example range:

• Pocket pairs: 22–AA (all)
• Suited aces: A2s–AKs
• Unsuited aces: AJo+ (ATo can sometimes be raised, but usually advised to fold)
• Suited kings: K9s–KQs
• Unsuited kings: KTo+, KQo
• Suited queens: Q9s–QJs
• Unsuited queens: QTo+, QJo
• Suited jacks: J9s–JTs
• Unsuited jacks: JTo
• Suited tens: T9s–T8s (fold T7s and worse)
• Suited nines: 98s–97s (fold 96s and below)
• Suited eights: 87s–86s
• Suited sevens: 76s–75s
• Suited sixes: 65s
• Suited fives: 54s

Note: The above range is a standard recommendation; in practice, adjust based on blind players and stack depth.

Range Construction Logic

Building the CO range follows three core principles:

1. Blind Steal Value: Include many hands that have high equity against the blinds' wide ranges (e.g., A2s, K9s) and hands that easily form strong draws (suited connectors).
2. Postflop Playability: Prioritize hands that easily flop top pair, flush draws, or straight draws, rather than pure air.
3. Squeezing Early Positions: Since the CO faces folded action from earlier positions, there is no need to worry about slow-playing from early position, so the range can be wider than UTG.

Typical logic:

• All pocket pairs are worth raising because they can easily flop sets and have good disguise.
• Suited aces (A2s–A5s) are excellent bluffing hands that can flop an ace or a flush draw and also block AK, AQ.
• Unsuited broadways (like KTo, QJo) are raised mainly to exploit weak calls from the blinds; if they miss the flop, you can continue c-betting to steal the pot.

Adjustment Factors

The range should be dynamically adjusted based on:

• Blind Player Tendencies:
  • If blinds call too often (>40%), tighten the range, remove low suited connectors (below 76s), and add more strong hands like KQo, AJo.
  • If blinds 3-bet too often (>10%), increase 4-bet bluff hands (like A5s, K9s) and reduce marginal hands.
• Stack Depth:
  • Short stacks (<40BB): Tighten range, mainly use strong hands to shove or raise, fold small suited connectors.
  • Deep stacks (>200BB): Add more speculative hands (like 65s, 44), but be careful to control pot size.
• Positional Factors: When the Button is yet to act, you can loosen up slightly; if the Button is an aggressive 3-bet player, tighten.
• Player Types: Against weak players (who don't fold and don't 3-bet), raise for value; against tight players (who fold too much), steal with all marginal hands.

GTO Reference

According to modern GTO solver results, under standard 100BB no-raise-before-you conditions, the optimal CO open-raise frequency is about 22%–24% (using standard 2.5BB raise). Core principles:

• About 70% of the range is used to raise (the rest folds), but some low suited connectors may be mixed in with folds.
• Within the raising range, value hands (those that can call a 3-bet) make up about 60%, and bluff hands about 40%.
• When facing a blind 3-bet, use TT+, AQ+, A5s, KQo, etc. to mix 4-bet and calls.

Note: GTO is a reference baseline; in practice, adjusting to exploitative strategies often yields higher returns.

Practical Application

Below are typical scenario examples:

1. Successful Blind Steal: CO raises to 2.5BB, SB folds, BB calls. Flop is K♠7♣2♥, you hold A♠5♠. Continuation bet 1/3 pot, BB folds.
2. Facing a 3-bet: CO raises, BU 3-bets to 9BB. If you hold A♦K♣, calling or 4-betting are both viable; if you hold T♦9♦, fold.
3. Against Tight Blinds: Blind players fold >70% of the time, you can add more hands like Q2s, J5s (but be cautious, recommended for study only, not high-stakes games).

Key Reminder: The CO position's strength lies in flexibility, but avoid over-stealing. Balance your range to prevent exploitation by 3-bets from the blinds.