CO 20bb Resteal

What is a CO 20bb Resteal?

In no-limit hold'em, the cutoff (CO) is the seat to the right of the button. A "resteal" is a re-raise (usually all-in) against a player who raised from a later position, typically the button or small blind, with the intent to steal the blinds. When the cutoff has a stack of about 20 big blinds, this play becomes a common tournament strategy.

Why 20 Big Blinds?

At 20bb, the stack is large enough to have fold equity (the chance the original raiser folds) but small enough that calling a raise and playing postflop is awkward. The effective stacks are shallow, making it difficult to profitably call and see a flop. A resteal all-in puts maximum pressure on the opponent, forcing them to decide with a hand that may not be strong enough to call a 20bb shove.

Typical Ranges

A CO 20bb resteal range includes hands that have good equity against a wide stealing range but are not strong enough to flat call. This typically includes medium suited connectors (e.g., 87s, 65s), small pairs (22-77), and weak to medium aces (A2s-A9s). The exact range depends on the opponent's opening frequency and tendencies. Against a loose stealer, you can widen the range; against a tight opponent, you tighten it.

Why Cutoff Specifically?

Being in the cutoff, you have a positional disadvantage to the button and blind players, but you are still in late position. At 20bb, flatting from the CO is often suboptimal because you'll be out of position against the button if they call, and your stack is shallow. Therefore, a resteal becomes a better alternative.

Mathematical Considerations

The required fold equity for a resteal to be profitable depends on pot odds. If the button opens to 2.5bb, the pot is 3.5bb (including blinds). A 20bb jam risks 20bb to win 3.5bb if everyone folds. To break even on fold equity alone, you need folds more than 85% of the time (20/23.5). However, when called, your hand's equity matters. With a hand like 76s, you have about 30-35% equity against a typical calling range. The overall equation involves both fold equity and showdown equity.

Adjusting to Opponents

• Against a tight player: They steal rarely, so only resteal with strong hands.
• Against a loose aggressive player: They steal often, so resteal with a wide range including speculative hands.

Tournament Stage and ICM

• Early in a tournament: Players call lighter; restealing is less effective because opponents may call with marginal hands.
• On the bubble: Fold equity increases as players avoid busting; resteals become more profitable.
• ICM pressure: If you are the short stack, ICM forces you to take marginally negative chip EV spots; if opponents are short, they may call tighter.

Example

In a tournament, action folds to the button who raises to 2.5bb. The small blind folds. You are in the big blind with 20bb and look down at 87s. You decide to shove all-in. The button folds. This is a typical resteal: you are exploiting the button's wide opening range, forcing them to fold hands that may have been stealing.

Conclusion

CO 20bb Resteal is a fundamental tournament play that balances risk and reward. Mastery involves adjusting to opponents, stack sizes, and tournament stage. It is an essential tool for exploiting aggressive players and accumulating chips without showdown.