A check-raise is checking to your opponent and then raising after he bets. It is the out-of-position player’s main weapon: it turns villain’s c-bet into a big pot when you are strong and adds fold equity to big draws.
Out of position you cannot bet first without giving away your hand and facing a raise, so you check — and when villain c-bets into a board that hits your range, you raise. For value, the check-raise grows the pot while you are ahead and denies the cheap turn card to his draws. As a semi-bluff with a big draw, it takes the pot down immediately often enough, and when called you still hold plenty of outs. Mixing the two keeps villain from reading the raise as ‘always the nuts’. Wet boards are where both halves work best.
Two limits keep check-raises profitable. Do not check-raise bluff on boards that favor the raiser: on A-K-x his range holds far more strong hands than yours, so a raise gets called and you are drawing thin. And do not lead into the raiser with your strong hands on boards he will bet — a donk bet takes away the c-bet your check-raise wants to attack. Slow-playing sets on wet boards ‘to trap’ is the other common mistake: every heart and straight card on the turn can kill your action.
Worked example
FAQ
When should you check-raise?
With strong hands and big draws on boards that hit your range — wet, middling flops where you hold sets, two pair and flush-plus-straight draws. Against a small c-bet with top pair on a dry board, just call; raising folds out his bluffs.
Is a check-raise always strong?
No, and it should not be. A balanced check-raising range includes semi-bluffs with big draws; if your raises are never draws, villain folds everything but his strongest hands and your sets stop getting paid.