关煞位25大盲注直接全下（CO 25bb Open Jam）

Overview

CO 25bb Open Jam is a common short-stack strategy in Texas Hold'em tournaments, specifically referring to directly choosing to go all-in when holding approximately 25 big blinds in the cutoff position (Cut-off, abbreviated as CO, which is the first position to the right of the dealer). This strategy is usually used to apply pressure against the calling ranges of the blind position players, leveraging stack depth and positional advantage.

Strategic Considerations

• Effective Stack Depth: 25bb falls into the mid-short stack range. At this depth, a standard raise might face a 3-bet from the blinds or difficult post-flop play after a call. Going all-in directly simplifies decisions and forces opponents to defend with a wider range.
• Positional Advantage: The cutoff is the last unentered position to act actively. After an all-in, the button (BTN), small blind (SB), and big blind (BB) must decide in turn. Due to positional disadvantage, the blind positions' calling ranges are usually tighter.
• Range Construction: The CO's all-in range typically includes strong hands (such as TT+, AQ+) and some medium hands (like small pairs, suited connectors) to balance value and bluffs. The specific range should be adjusted based on opponent tendencies and tournament ICM pressure.

Typical Example

Assume the blind level is 100/200, antes 25, CO has 5000 chips (25bb), and it folds to the CO. The CO decides to go all-in for 5000. The button, small blind, and big blind must decide in turn. If the big blind holds 99 or AJ, they might call; if holding weak hands, they fold.

Notes

• This strategy is especially common in the late stages of tournaments, as opponents tend to be more conservative under ICM pressure.
• In cash games, going all-in with 25bb may be seen as overly aggressive and should be adjusted based on opponents.
• If the stack depth is less than 20bb, the all-in range should be tighter; if greater than 30bb, a standard raise is usually recommended over an all-in.