Recognizing a Check-Raise Bluff

When you're stomping around in a jungle, it would probably be a good survival skill to be able to tell the difference between a cobra's hood in full display, and the one the frilled lizard tries to drive away danger with. This same paradigm applies to a check-raise that is done in order to scare you off, and one that is done to kill you. If a player in the early position holds their fire before the flop, only doing the bear minimum, and for the rest of the betting rounds only reacts to what the other players do, but springs a check-raise on the river, you can probably safely assume they believe they are holding the winning hand.