CO河牌干燥全下（CO River Jam Dry）
Refers to a situation in a poker hand where a player in the CO position Cutoff, to the right of the dealer makes an all-in jam on the river against a dry board.
Term Explanation
CO River Jam Dry is a common and specific play in Texas Hold'em. "CO" stands for Cutoff, the position to the right of the Button. Due to its relatively late position post-flop, it is often used for stealing blinds or value betting. "River" refers to the fifth community card, the final betting round. "Jam" is slang for all-in. "Dry" describes a "dry board" — a board texture lacking obvious drawing possibilities (e.g., straight draws or flush draws), typically composed of unconnected, unsuited high cards (e.g., K♠8♦2♣) or paired boards (e.g., A♥A♣3♠).
Strategic Implications
On a dry river board, players' hand strengths tend to be polarized: either strong made hands (top pair or better, sets, full houses, etc.) or complete air that missed. Thus, when a player in CO goes all-in, it is either to extract value from an opponent's weaker made hand (value jam) or to force an opponent to fold a medium-strength hand (bluff jam). Since dry boards offer few draws, the opponent's calling range tends to be narrower, making the bluff more effective. However, players must balance their range to avoid being exploited.
Practical Considerations
- This term commonly appears in online poker or strategy discussions, emphasizing the combination of position and board structure.
- In practice, the CO player must consider factors such as opponent type, stack depth, and prior action — this strategy should not be used mechanically.
- A dry board is not always safe; one must still be wary of opponents holding hands like pocket pairs or bottom pair.