Beating the Blocking Bet

If in a game of No Limit Holdem you encounter a player in an early position who puts in a small to medium sized bet on the river, what is probably going on here is that they are putting in a blocking bet. The player would prefer that you respond to them by calling their small bet, than checking and leaving the next action up to you. Left to your own devices, you might put in a bet bigger than the one they would enter. A player who is trying to get to the showdown as cheaply as possible will want to avoid investing heavily in that last betting round.