Isolating opponents in poker is a valuable tool to utilize in your quest to become a well-rounded and consistently winning player. But if we are to use isolation as a tool we first have to answer the fundamental question, How do we define isolation?
In its simplest form, isolation occurs when we raise a player who has entered a pot (usually by limping) with the goal of getting that limper heads-up, ideally in a scenario where we can win the hand more often than not. We do not want to do this with just any player — rather, there are a certain set of scenarios where isolation is most effective. If you see a player limping in often and then folding post-flop when they do not hit their hand, make a mental note of it. Keeping track of individual’s VPIPs (the amount of times they Voluntarily Put money Into the Pot, hence the initials, VPIPs) is perhaps the most valuable observation you can make at the table, as I describe an ideal isolating scenario.
Let’s assume that you have been at the table for a while, and you have kept good track of the VPIPs of all of your players. You are in the cutoff (to the right of the button) and a player that has been limping often does it once again. Here is where we look to our left to assess what the players yet-to-act are likely to do. What has the player on the button been doing? Is he a tight player? Does he loosen up on the button? How about the blinds? Do they often cold call 3bet raises? The makeup of individuals yet to play is crucial when you attempt to isolate. It is a piece of the puzzle that defines why you might isolate here.
After assessing what the players to our left may do, we must return our attention to the limper on our right. From prior observation, you should have had several opportunities to see his hands at showdown, from which you can begin gathering your read on the player. For our example, we can follow the most typical scenario; the player is likely raising with high value hands and limping with a lot of speculative hands, if he is voluntarily putting money into the pot pre-flop
There are several other consideration that you should consider when using an isolation play.
Hand selection is important. Obviously, hands that are on the higher end of your range will mean that once you are heads-up, post-flop, you will likely be ahead. Even hands like Ace-high, though, can be useful for an isolation play, particularly if the flop is uncoordinated, such that your opponent likely missed it. In those scenarios, you are often ahead with your Ace (assuming your opponent just flat-called your pre-flop raise), and even if you are behind, a well-timed continuation bet can usually make a player fold their hand, if it did not connect and you showed strength pre-flop with your raise.
Of course, getting heads-up with an isolation play is only half the battle. Once heads-up, you need to capitalize on the situation. Otherwise, you may just be isolating yourself into a losing hand. For this reason, you must rely heavily on your observations prior to the hand. You should be particularly aware of your opponents’ betting patterns post-flop. If the player you isolated pre-flop bets on the flop, it does not necessarily mean that he has hit his hand. Oftentimes, players learn to continuation bet at or near 100% of the time. Knowing whether your opponent continuation bets constantly or is timid post-flop will help you avoid isolating an opponent, only to hand the pot over to him once you are heads-up. You must consider things like how often does he see the turn? You also want to know what type of hands he values enough to take to the river. Have you seen him showdown a lot of one-pair hands? Consider his common betting patterns. When a novice player deviates from his normal behavior, he is either very strong or very, very weak. Our goal is to punish him for putting himself in weak situations in the first place. As a result, our hand holding often does not matter!
The key lesson to learn is that it is as important, if not more important, to understand the ’why’ of the hand, and not just the ’what.’ If your opponent bets heavy against you post-flop, your goal to isolate is probably no good this hand, so it does not really matter if we have KK or 6d8d. In that scenario, isolation is almost irrelevant, and you would be best served by playing your strong hands accordingly and tossing your speculative holdings; that said, if we can assume that your opponent will fold a good percentage of the time post-flop after limping pre-flop, then you will be almost assured of being profitable against that player in the long-term.