Check behind
To check behind is to check in last position after your opponent has already checked, which ends the betting round and takes you to the next card for free.
It is the cheapest way to keep a hand that wants to reach a showdown. Betting a marginal hand often only gets called by better and folds out worse, and checking behind keeps every hand you beat in the pot.
The cost is that it also gives a free card to whatever is drawing against you. That trade is the whole decision: a board where little can improve is a fine one to check behind on, and a board full of draws usually is not.
an example
your cards
board
The river is out, your opponent checks and you hold queen jack with no pair. Betting only wins if they fold a better hand, and they will not fold an ace. Checking behind loses the pot but saves the bet.
This example is made up. The real one is in your own hand history: find check behind in your own hands and see how often it came up and what it cost you.
related terms
Check
To check is to pass the action to the next player without betting, which is only allowed when nobody has bet before you ...
Give up
To give up is to stop betting a hand you have been bluffing with and let the pot go, because another bet costs more than ...
Showdown value
A hand has showdown value when it can win by simply being shown at the end, without needing anybody to fold.
next
Knowing the word is not the same as seeing it.
Forty hands against a bot, no account, and your own hand history at the end.