CO 20bb Steal

Definition

A CO 20bb Steal refers to a raise made from the cutoff (CO) position when the effective stack size (the smallest stack among active players) is around 20 big blinds (bb). The primary goal is to "steal" the blinds and antes—i.e., to win the pot preflop without confrontation. This play is most common in tournament poker, where stack sizes are deep enough to allow significant fold equity but shallow enough to make ICM considerations critical.

Strategic Context

At 20bb, the cutoff is in a strong position to open-raise. The players left to act are the button, small blind, and big blind. The button often has a wide defending range, but the cutoff's raise can still be profitable if the blinds are tight. The standard raise size for a steal at this stack depth is typically 2.0–2.5bb (sometimes 2.2bb). A larger raise (e.g., 2.5bb) reduces the risk of being called by marginal hands but also lowers fold equity against aggressive blinds.

Range Considerations

The cutoff's opening range at 20bb should be wider than in earlier positions but tighter than on the button. A typical GTO-inspired range might include about 30–40% of hands: all pairs (22+), suited aces (A2s+), some offsuit aces (A8o+), broadways (KJo+, QJo+, and suited connectors like 65s+, suited one-gappers like 75s+), and some suited kings (K9s+). However, adjustments depend on the tendencies of the players behind. Against tight blinds, the range can widen; against loose or aggressive blinds, it should narrow.

Defenders' Responses

• Button: Often calls with a wide range (20–30% of hands) and 3-bets with value hands (JJ+, AK) and some bluffs. The cutoff must consider the button's stack size; if the button also has about 20bb, they can shove over a raise, putting the cutoff in a tough spot.
• Small Blind: At 20bb, the small blind is incentivized to protect their stack; they may call more often with speculative hands or shove with a polarized range.
• Big Blind: The big blind gets a discount and can defend widely (e.g., calling with many suited cards and pairs). A common mistake is defending too many weak offsuit hands.

Post-Flop Play

If called, the cutoff should have a range advantage on most board textures because they hold more high cards. With 20bb, the effective stacks are small relative to the pot, so post-flop decisions often lead to all-in situations on the flop or turn. The cutoff should c-bet frequently on low boards but may check back on coordinated boards that hit the defender's range.

ICM Implications

In tournaments, ICM pressure affects stealing at 20bb. In the money bubble or near pay jumps, tight players are more likely to fold, increasing the steal success. However, short stacks (under 15bb) may shove over a raise, forcing the cutoff to fold if they have a hand that isn't strong enough to call.

Example

Blinds 500/1000 with a 100 ante (9 players, pot 2400). Hero in CO with 20,000 chips (20bb). Holding A♠7♠, Hero raises to 2200. All fold. This is a successful CO 20bb steal.

Conclusion

The CO 20bb steal is a fundamental tournament poker move. Success depends on reading opponents' tendencies, adjusting raise size, and understanding the implications of stack depth and ICM. Mastering this spot is essential for building a chip stack without showdown.