关煞位河牌五注彩虹面（CO River 5-Bet Rainbow）

Term Introduction

CO River 5-Bet Rainbow is a compound term that combines position (CO), street (River), number of raises (5-Bet), and board texture (Rainbow). In Texas Hold'em, this term describes an extremely rare scenario: a player in the CO position makes the fifth raise on the river, while the three flop cards are all of different suits (i.e., a rainbow board).

Components

• CO (Cut-Off): The cutoff seat, i.e., the first position to the right of the button. It is a late position, offering informational advantage.
• River: The river, the final betting round, after all community cards have been dealt.
• 5-Bet: The fifth raise. Typically, in a betting round, raises are counted from preflop: e.g., preflop someone opens (bet), someone 3-bets, someone 4-bets, then someone 5-bets. Postflop, consecutive raises can similarly be called 3-bets, 4-bets, etc. A river 5-bet means four raises have already occurred on the river, and the current player makes the fifth raise — extremely rare.
• Rainbow: A rainbow board, meaning the three flop cards are all of different suits, usually reducing the possibility of flush draws.

Strategic Implications

Since a river 5-bet is almost never made with ordinary hand strength, it typically represents:

• Extremely strong hands: such as the nut flush, full house, or better.
• Rare bluffs: making an ultra-high-frequency bluff-raise on the river — success rate is extremely low. A rainbow board further reduces the chance that opponents hold a flush draw, so a 5-bet for value is more likely targeting made hands. Generally, a river 4-bet or 5-bet occurs primarily in deep-stack situations where both players have very strong holdings.

Notes

This term is not a standard poker term; it is more descriptive. In actual play, river 5-bets occur extremely infrequently. The "rainbow" description mainly emphasizes the flop texture, unrelated to the river itself, but is used as part of the compound term for a complete scenario description.