Check-raising, as the name suggests, involves checking in front of an opponent in the hope that one or more players makes a bet. When the action gets back to you, you raise. It's generally a good idea to be holding a very strong hand when you do this as many players like to call down check-raisers 'just to see,' and the increased money in the pot can sometimes create situations where it becomes correct for your opponents to call with all kind of crazy draws.
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