word type: verb
In various poker games a player will often use a blocking bet on the river to keep things at a more reasonable price. The alternative of checking and having to call down against a bet much larger than a blocking bet is often the very reason why people put one out there instead. The problem with block bets, however, is that you are still faced with the possibility of your opponent raising. Since block bets look weak, it is then hard to determine whether or not your opponent actually has a hand or he is simply bluffing. Generally, it's best not to make a block bet if you're opponent's range is weighted more heavily towards two-pair or better - just check-fold.
Example - A Good Time for a Block Bet
Let's say you hold KhQs in the BB and the action folds to the player on the button who opens for 3x. You decide to flat and the flop comes down Ah-Qh-4s. You check-call you opponent's c-bet and the turn brings the 7h. The action goes check-check and when the 3d falls on the river, you're unsure of what to do. This is a good spot to try a block bet, mainly because in reality, it might actually be a value-bet. It's completely reasonable for your opponent to have an ace, and if you check to him, he is most certainly going to try and extract value from you, thus making a small bet will save you from calling the larger bet that he's going to make a good percentage of the time. However, it's also within the realm of possibility that your opponent has 55, 66, 88, 99, TT or JJ, in which case he is probably going to call a small bet. Regardless of what your opponent actually has, this is a good time to try a blocking bet.