小盲位河牌浮标（彩虹面）（SB River Float Rainbow）

This term rarely appears in mainstream poker literature, strategy videos, or player communities. It may originate from individual textbooks or informal usage in specific contexts. Typical scenario: The small blind calls preflop, the flop is a rainbow board (all three cards of different suits). The small blind checks or calls on the flop, then calls again on the turn. On the river, since no flush is possible and the board structure is relatively dry, the small blind may use position (if heads-up, they are out of position, but usually the SB is out of position postflop) or exploit weaknesses in the opponent's range to bet the river. This line generally requires an opponent who folds easily and the small blind’s own hand to be very weak or to have certain blockers. However, because the term lacks a precise definition, it is recommended to use more standard phrasing in discussions, such as "small blind river float on a rainbow flop" or simply describe the specific situation. In practice, note that rainbow boards reduce flush draws but may increase straight draws, so the float must be timed carefully.