You know the saying 'the best defense is a good offense'? Well, the blocking bet embodies this sentiment. A blocking bet (also known as a blocker bet) is used when you’re the first to act and you make a bet that's relatively small compared to the average bet size in an attempt to trim the monetary amount you'll have to put out to see the subsequent cards.
You make this small bet assuming that your opponent will not raise. The idea is that you'll only have to call what could have been a much larger bet had you decided to check. By making a blocking bet, you're being proactive. You're thinking ahead. You're keeping it real - and by real, I mean as cheap as possible. Presumably, you want to stay in the game long enough to make some serious coin (or at least get a decent return on your initial investment).
You can use the blocking bet at any stack size, but it is particularly useful when your stack has dwindled and your chip stack needs some TLC. In fact, just think of the blocking bet as life support for your bankroll.
Sounds good, right? Even, perhaps, a little miraculous. Well, it's not. You have to make this maneuver work for you.
The Blocking Bet: Making it Work
First, you need to understand that the blocking bet only works when you're not in position. The point of this maneuver is to see the next card or get to a showdown without having to front piles of cash. You also have an expectation that, had you checked, your opponent would have made a hefty bet. (After all, if you suspect your opponent was going to check after you, then you're not making a blocker bet. You're just cushioning the pot.)
This brings me to the next consideration, and probably the most important. To pull off a blocking bet, you have to have a handle on your opponent. You have to be experienced enough to know how to read other players. You can't make the call on whether or not your opponent will call or check if you don't know how to read them, right? Right.
Now, let's talk about the two situations where you will want to utilizing the blocking bet. They are:
1. When you have a drawing hand. In the event you make your hand, you’ll be paid off. Utilizing the blocker bet not only stopped your opponent from making a bet you couldn't afford to call, but it also effectively disguised your holdings. If you don't make your draw on the river, it's usually best (read: safest) to check and fold. We also get a little value of a small bit of fold equity. Sometimes we can move our opponent off a hand they would have otherwise bluffed had we chosen to check.
2. When you're on the river and you have a made hand that's venerable. Using the blocking bet on the river is an exceptional way to stonewall a chronic bluffer who may have made a monster bet on fifth street (whether based on their actual holdings or total air). Even if you just have a mid-strength hand, a blocking bet can let you see the showdown affordably.
Blocker Bet Sizing
There's no hard and fast rule here. You just need to bet enough to dissuade your opponent from bluffing, but keep the bet size small enough that you can swallow the loss without choking in the event your opponent has the nuts and raises. This means the exact size of your blocking bet is going to be on a sliding scale. Yes, the bet is going to be comparatively small (when compared to the average bet size) but it should not be so small that your opponents suspect your strategy. If they suspect this, they will simply come over the top and the blocking bet will have been in vain.
This said, some opponents will read your blocking bet for exactly what it is, and you can actually use a blocker to INDUCE a bluff from them where they would have otherwise possibly checked back with a worse hand or bluffed for less. You’ll get more value from the hand and you’ll have pulled off the move. However, you really have to be able to read your opponents for this to work, so I’d only recommend this tactic for expert players.
The way to overcome this obstacle is to mix up your play with value bets so your opponents will see that most of the time, you do act with solid holdings. By doing this your opponents will not be able to tell if your small bet is a blocking bet or a value bet and as such, they won't know how to act. Denying them this solid footing is what is going to secure your success – and the more mistakes your opponents make, the better for your bottom-line.