枪口+1位河牌圈4-Bet彩虹面（UTG+1 River 4-Bet Rainbow）
On the river, the player in the UTG+1 position makes a fourth raise 4-bet with a rainbow board three cards of different suits.
Term Explanation
“UTG+1 River 4-Bet Rainbow” is a highly specific poker scenario that combines position, betting round, number of raises, and board texture. Typically, a 4-bet occurs preflop, but postflop, after three raises have already occurred (e.g., a bet on the flop, a raise on the turn, and a raise on the river), an additional raise is referred to as a river 4-bet. In this term, “Rainbow” indicates that all three cards of the community board (usually the flop) are of different suits, meaning no flush draw is possible.
Strategic Implications
On the river, a 4-bet from UTG+1 (under the gun +1, i.e., the second position to the left of the big blind) typically represents extreme hand strength. Since this position is early, the opening range should already be tight, and a river 4-bet almost only occurs when holding the nuts or a near-nut hand. The rainbow board eliminates flush possibilities, so the player's strong hands come from made hands (e.g., straights, trips, two pair, etc.) or bluffs. However, at such a high betting level, the probability of bluffing is extremely low because the opponent’s calling range is already strong.
Typical Example Scenario
Suppose the flop is 8♥ 5♠ 2♦ (rainbow), the turn is Q♣, and the river is A♠. Player A is in UTG+1, calls on the flop and turn, then on the river after an opponent bets, Player A raises, the opponent re-raises, and Player A then raises again (i.e., the 4-bet). This sequence indicates that Player A believes their hand is far stronger than the opponent's pot-committed range.
Notes
In actual play, a river 4-bet is extremely rare, typically occurring only in deep-stacked or highly aggressive games. When analyzing this term, note that different poker terminology systems may label postflop raising sequences differently; some players may simply call it a “river re-raise” instead of “4-bet”.