Sometimes when you face a small bet on the river by your opponent you just know that he is not strong. A lot of bad players put out block bets on the river from out of position to name their price to make sure that they can showdown their hand. They do not want to get bluffed out of the pot so instead they bet an amount that they are comfortable calling.
There are a number of reasons why block bets usually are not a good approach to scary rivers. First and for most if your opponent is going to bluff why would you prevent him from bluffing through block betting? I never really understood this line of thinking by low and sometimes midstakes players. Secondly, if you think your opponent has you beat because of his bet sizing and his hand looks like value then fold.
There have been many times that I did not know quite what to do on the river until I saw how my opponent acted. Often times I hear players say “I didn’t want him to bet too much because then I couldn’t call.” Do you see what is wrong with this line of thinking? It doesn’t matter how much your opponent bets at the end it only matters if you think you have the best hand given the pot odds. Poker players that are thinking about folding because their hand is not a 200 dollar hand are not thinking about the game in the correct manner. You should not be examining your own hand strength in an absolute sense but whether or not you have the best holding. Sometimes I may fold top set on the river. Sometimes I might call with king high. But to say that I want to prevent my opponent from betting a lot is ludicrous and it stems from people always wanting to get to showdown.
If you are good at hand reading you can really exploit block bets through bluff raising. Sometimes players will convince themselves to call anyway so be careful. This reminds me of a hand that I played at the Seminole Hard Rock Poker Open this week. We were in the early stages of the tournament and a player from under the gun raised to two and a half times the blind. I was in the cutoff with 9♠ T♠ and called and a very big fishy player also called in the small blind. The board ran out K♣ Q♣ 5♦. The small blind checked and the preflop raiser made a standard continuation bet. A lot of the times I fold here but I thought that if I floated this board the preflop raiser would just check fold the turn so I called. Much to my dismay the small blind called as well. His range was extremely wide—a king, a queen, a flush draw or a straight draw were all in his possible holdings. The turn came the 2♦ and the small blind checked again. This time the preflop raiser also checked and this gave me the green light to stab at it and win a nice sized pot. I knew that the deuce did not change anything but also brought an additional draw to the board. I thought that if the preflop raiser had at least top pair he would almost certainly bet again to win the pot or get value from the draws. Unfortunately the stubborn small blind took some time with it and called again and the preflop raiser folded. I really thought that the small blind now either had a weak king or combination flush draw plus pair or straight draw. The river came the Q♦ for a final board reading K♣ Q♣ 5♦ 2♦ Q♦.
Now to some that may have looked like a scary card. But in reality I actually thought it was not that scary at all. There is no way that this guy was holding on with just a queen the whole time and the fact that the river was the Qd meant that he couldn’t have a flopped middle pair that turned a flush draw. If I was certain that this guy wouldn’t fold a king if it was checked to me I most likely would have under bluffed the river as my hand had no showdown value. However, surprisingly he came out and bet about 1/5 if the pot which was 1800. I just didn’t believe that someone would bet so small when they made a backdoor flush and correctly sussed this out as a blocker bet with a king. I then had to determine if I thought he would fold a king as many players will block the river yet still call a raise even though the action is counter intuitive. But here I figured if I made it 15k which represented about half of his stack he would fold. He ended up taking a very long time with it and eventually dumped his hand.
So you can see that his weak sizing at the end coupled with my ability to read his hand really created quite a profitable bluff raise situation.