Cutoff Opening Range Guide: Building a Balanced and Exploitative Preflop Strategy

Position Scenario Explanation

The Cutoff (CO) is located to the right of the Button (BTN) and is a position with significant post-flop positional advantage. Since only BTN, Small Blind (SB), and Big Blind (BB) act after CO, and BTN's 3bet range is relatively wide, CO's open must consider the risk of being squeezed by BTN. However, compared to early positions (such as UTG), CO still has a wider opening range.

Recommended Range

Default Balanced Range (100bb effective stack, no specific exploitation)

• Value Raises (approximately top 10% of hands): AA-77, AKo-AJo, AKs-ATs, KQs-KTs, QJs-QTs, JTs, T9s.
• Mixed Raise/Call (approximately top 12%-20%): Middle pairs 66-22, suited connectors 98s-76s, suited one-gappers K9s-Q9s, suited Ax (A5s-A2s), etc.
• Overall Raise Range: Approximately 25% of starting hands. Specifically includes:
  • All pairs (22+)
  • All suited Ax (A2s+)
  • All offsuit AK-AJ, KQ
  • Some suited Kx (K9s+), Qx (Q9s+), Jx (J9s+)
  • Suited connectors (T9s-65s) and suited one-gappers (98s-76s, T8s, 97s, etc.)
  • A small number of offsuit connectors (e.g., T9o, JTo, QJo) can be mixed between raise and fold.

Range Construction Logic

1. Position Advantage: CO always acts last post-flop (unless BTN or blinds act first), so the range can be wider, leveraging position to extract value or bluff.
2. 3bet Defense Balance: The range must include enough strong hands (value combos) and bluffs (suited connectors, small pairs, etc.) to prevent BTN's 3bet from being easily profitable.
3. Blind Defense: Since the small and big blinds defend with wide ranges, CO should use more medium-strength hands (e.g., KJo, QTo) to realize equity post-flop.
4. Avoid Over-Stealing: When BTN or blind players 3bet frequently, tighten the range (remove weak Kx, weak Qx, and low suited connectors).

Adjustment Factors

• Opponent Tendencies:
  • If BTN is too passive (rarely 3bets), widen the range to about 30%, adding many marginal hands like A9o, K9o, Q9o.
  • If BTN 3bet is frequent (over 12%), tighten to about 20%, mainly keeping pairs, strong Ax, and suited connectors.
  • If blinds defend weakly (high fold or call rates), frequently open with small raises (2bb) to steal blinds; range can include any two cards, but balance must be maintained.
• Stack Depth:
  • Short stacks (<40bb): Use push/fold strategy; range includes all pairs, Ax, Kx; suited connectors can be discarded.
  • Deep stacks (>150bb): Avoid hands easily dominated (e.g., KTo, QJo); increase suited aces and small pairs.
• Game Dynamics:
  • If your image is loose-aggressive (high raise frequency), tighten appropriately to get more action when holding strong hands.
  • If your image is tight-weak, significantly widen range to steal blinds.

GTO Reference

According to modern GTO research (e.g., PokerSnowie, PioSolver, with 100bb standard no antes), CO's equilibrium opening range to 2.5bb is approximately 23%-25%. Below is a typical range example (approximate combination counts):

• All pairs (22+): 78 combos
• All suited aces (A2s+): 28 combos
• All offsuit aces (A9o+, K9o partially folded): about 60 combos (including AKo-A9o)
• All suited K (K9s+): 20 combos
• All suited Q (Q9s+): 16 combos
• All suited J (J9s+): 12 combos
• Suited connectors (T9s-65s): 16 combos
• Suited one-gappers (98s-76s, T8s, 97s, etc.): about 16 combos
• Some offsuit connectors (QJo, JTo, T9o): 12 combos
• Total approximately 258 combos, corresponding to 19.5% range (Note: slightly tighter when using 2.5bb raise).

Actual GTO ranges adjust slightly based on antes and blind sizes. For reference, simplify to:

• All pairs + all suited aces + all suited connectors + K9s + Q9s + J9s + A9o + KJo + QJo.

Practical Application

1. Use Position to Steal Blinds: When the BTN and blind players are both fold-prone, you can raise to 2bb with any two cards, especially when the blinds are tight-passive.

2. Responding to 3-bets: With JJ+, AK, AQs, always re-raise; with medium pairs (99-77) and suited connectors, call if pot odds are favorable; with weak hands (KTo, QTo), fold directly to avoid being exploited.

3. Post-flop Frequency: The CO's continuation bet (C-bet) frequency should be high (around 70%), using position to apply pressure, but note that you should check occasionally on wet boards to protect your range.

4. Against a Tight-Aggressive BTN: If the BTN 3-bet range is very tight (only QQ+, AKs), the CO can widen its raising range and fold frequently to 3-bets, while trapping with AA/KK.

5. Exploiting Game Dynamics: Observe opponent data; if a particular opponent raises from the CO too often (>30%), attack their range with 3-bets, and use TT+/AQ+ for 4-bets.

Remember: The CO is one of the best positions post-flop, but it is also a position where you can easily over-steal and make mistakes. Keep your range balanced and adjust to specific opponent dynamics to achieve a steady profit.