1. Hands that cannot tolerate the multi-way environment that is being threatened and need to raise to prevent it. We shall call these iso hands (short for isolation).
2. Hands that actually benefit from the multi-way environment and want to accept it by limping along.
3. Hands that are put off raising by the lower fold equity (our chance of making our opponents fold) caused by the limp or limps, and that are not suitable to limp along and play multi-way. These hands will we shall simply fold.
1. IsolatingThe first question we should ask ourselves when encountering limping before us is whether our hand will benefit the most by making an iso-raise. In my book, The Grinder's Manual, I stipulated three key attributes that make a situation a good one in which to iso. Here they are:
(A) Frequent Strength: This factor is all about how frequently our hand will make something strong on the flop. By 'frequently' we mean hands that are easy enough to flop such as top pair decent kicker or a flush draw. Powerhouse hands such as sets are very nice, but they do not come around often enough to be called 'frequent'. Consequently, we should think of starting hands such as AA, QQ and AQs as having a great deal of frequent strength; hands like KJo and A5s as having a fair amount of it; and hands like 44, 54s and A6o as having relatively little.
(B) Fold Equity: This concept is central to the EV of so many of the decisions we make as poker players. A good interpretation of 'fold equity' is simply the percentage of the time that our opponents fold, thereby increasing our EV (Expected Value). While we cannot know the exact numerical value of our fold equity, we can estimate whether it is likely to be higher or lower based on how many people have limped, the player types who have limped, and how many loose players there are left to act behind us. The better the fold equity appears to be for us, the weaker the required frequent strength of our hand for isolating.
Example 1: Let's imagine that two very loose reckless players limp in UTG and the HJ and the action reaches us in the CO. We also know that the BB is very call-happy and is likely to be easily tempted by a multi-way pot. This is clearly a situation in which we need greater frequent strength to isolate. Here, hands that flop good one pair a lot like AJo or QJs are still worth trying to thin the field with as they crave a heads-up, or at worst, a three-way pot. However, in this situation we will not be able to raise too many worse hands than these due to the likelihood of being called by multiple opponents.
Example 2: This time the action reaches us on the BU. CO has limped, but he is a very passive and fit-or-fold player, likely to give up either now or when he does not connect too well with the flop. The blinds are tight and not looking to get involved in pots lightly. This is an enormously different spot to the example above. Now we should gladly isolate with hands as speculative as 85s and K8o. All of the conditions are right for it. In other words, we have a great deal of fold equity so we need very little frequent strength.
(C) Position: Being in position (acting last post-flop) is a very powerful advantage indeed. The power of information and heightened control over when money goes into the pot vastly increases EV in almost every situation where stacks are relatively deep. Therefore, being in position increases the EV of any poker investment, especially making an iso-raise. While this factor is not quite as impactful as the two preceding ones, it can tip the balance very easily in favour of deciding to iso. In Example 2 above, we might not be so eager to isolate as wide as 85s if we were in the SB and had to act first on every subsequent street. The weakest hand I would raise with in that instance might be something like 87s, 76s or JTo. Position can be a real deal-breaker when it comes to isolating.
Note that the requirement for these three factors is inversely proportionate. The more of A we have the less of B and C need. The more of B we have the less of A and C we need and so on and so forth.
The limper has created extra incentive for other players to join in the fun. This means that we should take extra measures to dissuade them when we have a hand with which we desire to thin the field. A good rule here is:
Raise to 3BB plus one extra BB for each limper and each very loose player left to act behind. Add a further BB if limpers have position on us.
This creates a preemptive disincentive for our opponents to create a multi-way environment that our hand cannot tolerate. For example, if we are on the BU, two players limp, and one calling station waits in the blinds, we might want to size right up to 6BB (3+1+1+1).
2. Limping AlongIt is almost never okay to open-limp (limp as the first player into the pot) in 6-max cash because open-raising is almost always a better play. Limping behind other limpers however, is a different beast altogether and something we might often consider. There exists a type of hand that actually prefers the multi-way climate caused by the limper. These are hands with low frequent strength, but high implied odds.
Hands with high implied odds are ones that are currently experiencing a favourable ratio of investment to average payout if they connect in a huge way. It follows that high implied odds hands are hands that are capable of connecting in a huge way some meaningful amount of the time. We shall take 'huge' here to mean better than one pair. The natural candidates for limping behind then are small pocket pairs like [22-66] and suited connecters that do not make large pairs EG. 87s. By getting in cheaply with these hands after a limp, where fold equity is already shrinking, we keep our investment down the times we miss and are forced to give up on the pot, while still giving ourselves the chance to flop a huge hand. The more opponents that enter the pot, the better our implied odds become as the chances of being paid of increase. We can see that the limpers create an environment that these hands are actually happy to see.