Knowing how likely it is that your opponent is either value betting or bluffing on the river can be the difference between a winning and losing player
Using what’s known as the VB-ratio (value-to-bluff ratio) it’s possible to deduce how many hands your opponent could be value betting with (i.e. they think their hand will be good enough to win the pot) and how many they are bluffing with.
How to Calculate a VB-ratio?
The first thing you need to do before launching into a breakdown of a player’s bluff hands and value hands is to segregate their range into these two parts. Once you’ve done this you need to assess how many hands you believe to be in your opponent’s bluff range and their value range.
Using the funnel principle (whereby you filter down a player’s potential range as a hand develops) you should have some idea of how many potential hands a player has that could be winners at showdown. Once you’ve worked out the number of potential value and bluff hands they could hold, you need to break down the number of combinations these hands equate to (you can use PokerStrategy.com’s Equilab to easily find the amount of combinations you’re facing).
After assessing the number of hands your opponent could have and then using Equilab to breakdown the number of combinations this total entails, you can then put this into a useful equation.
For example, if your opponent value bets #60 (60 combinations) and bluffs with #30, then the VB-Ratio is 60/30, which gives 2:1. Your opponent therefore has two value hands for every bluff. Or put differently, he value bets twice as often as he bluffs.
Using the VB-ratio
Once you’ve established the VB-ratio you can then use it to guide whether or not you should call, fold or even raise on the river. Basically, if the VB-ratio is smaller than the pot odds that are facing you, then you can profitably make a call with any hand that beats your opponent’s bluffs.
For example, if you’re facing pot odds of 2:1 on the river and you’ve calculated that your opponent’s VB-ratio is 2:1 then you can justify making a call (mathematically) with any hand that beats their bluffs.
Now that we’ve established the basic principle of calculating the VB-ratio and how you can use it to guide your river decisions, let’s put it all into a real-life example to show you how you can use it at the table.
Look at the following example for the calculation of the VB-Ratio. A LAG in the BB calls your button raise (you have Q♠-J♦) and check/raises you on a Q♥-9♠-7♦ flop.
You estimate his average pre-flop range that he calls with from the BB to be: 99-22, ATs-A6s, KJs-K8s, Q8s+, J8s+, T8s+, 97s+, 87s, 76s, 65s, 54s, AJo-A7o, KJo-K8o, Q9o+, J9o+.
You deduce that your opponent’s VB-Ratio could look something like this:
A LAG will raise two pair+ here for value which means he could have Q-9 (6 combinations) and 9-7s (two combinations). To this we can add sets into his range with 9-9 (three combinations) and 7-7 (three combinations). Overall this gives us 14 value combinations.
In terms of bluffs we can throw in open-ended straight draws which equal J-T (12 combinations) and T-8s (four combinations) as well as gutshot draw such as K-J (12 combinations), K-T (16 combinations) and J-8s (3 combinations). In total that makes 47 combinations.
One important point to note when going through this process is that you should try and determine the value range as accurately as possible because it will usually be small. In contrast, a player’s bluff range is usually quite large and therefore can’t be determined as accurately during live play.
After looking at the dynamics, the VB-ratio from our example would look like this: 1:3.4 (in live play you can simply say it’s between 1:3 and 1:4).
Turn: Q♥-9♠-7♦-3♣ (pot: $4.90)
Action: BB bets $4, Hero calls $4
At this point the turn doesn’t change anything and your opponent will bet again with all of his range.
River: Q♥-9♠-7♦-3♣-6♥ (pot: $12.90)
Action: BB bets $10
On the river you now need to take your opponent’s VB-Ratio into account before you make your decision. You already know that you can call if your opponent bets less than the pot size (a pot sized bet would give you pot odds of 2:1) and the VB-Ratio is 2:1 or less. It is therefore sufficient if your opponent’s betting range on the river includes half as many bluffs as value hands.
The fastest way to make a decision is by determining your opponent’s value range and then taking half of it. You then start counting his bluffs and as soon as the bluffs reach half the number of the value bets you stop counting and make the call.
In this case, your opponent value bets the same hands as he did on the flop as well as T-8s which will have made a straight on the river. Together this makes 18 value combinations. Thus, if your opponent has nine bluff combinations, this will be enough for you to make a profitable call. By quickly scanning our previous breakdown you can see that your opponent would bluff with K-J, K-T, J-T and J-8s, which is more than the nine bluff combinations required for you to make a profitable call in this spot.
When you’re faced with a tough decision on the river it’s important to consider a player’s VB-ratio before you make a move. By comparing the amount of time someone could be bluffing and value betting versus the pot odds, you should be able to improve your long-term EV when it comes to make calls and folds on the river.
This lesson was brought to you by the Poker School at PokerStrategy.com.