Set Mining

What is Set-Mining?

• Set-mining
  is where we call pre-flop with the sole intention of flopping a set. We are not concerned about making plays post-flop, or attempting to get to showdown. If we don’t flop a set we will fold immediately to any action.
• In order for a set-mine to be profitable, it is necessary to win a certain amount of chips on average when we make our hand. We don’t necessarily know the exact amount we will make, but it is possible to make good estimates. These will be based on villain’s tendencies and the stack sizes.

How Much do I Need to Make?

The answer to this is based on how often we will flop a set ; 11.8% of the time. Assuming we were to stack villain 100% of the time when we flop a set, we need to make 7.5 times our initial investment, or invest a maximum of 13.37% of the effective stacks. (See below if you are interested in how this was calculated)

The Maths

Hopefully you are familiar with the extremely useful and simple formula -->

% equity = % of total pot you can invest

If we were to stack villain 100% of the time time when we flopped a set, otherwise lose; we would essentially have 11.8% equity, and can therefore invest 11.8% of the total pot. (By total pot here, we are talking about total implied pot - the amount we can potentially win from villain compared to the size of just our pre-flop investment.)

HOWEVER

 In practice these calculations are inaccurate for the following reasons...

Even when we hit our set sometimes -

• We don’t get villain’s whole stack
•  Villain has a higher set or other better hand which beats us
• Villain gets all-in with worse but makes a better hand by the river
• We think our set might not be good and end up folding

Although on the plus side...

•  Sometimes we see free turn/river cards so don’t need to hit directly on the flop
•  Sometimes we win even when we don’t hit our set.

The first category (which reduces our equity), vastly outweighs the second category (which increases our equity). The result is that our calculations need to be far more conservative. This is how we arrive at the common poker rules detailed below.

Two Main Rules

There are two main rules which are often cited in connection with set-mining.

Call 20 rule

“You need to be able to make 20 times your initial investment after the flop”

If our opponent open-raises to $1, in order to call we need to be able to make $20 after the flop. If our opponent does not even have an extra $20 left in his stack, this will not be possible. We don’t need to make 20 times our pre-flop investment on average, but in order to make up for the times when we don’t extract any value post-flop or we run into a higher set and lose; it is necessary to be able to make more than the average amount on other occasions.

5-10 rule

“Don’t invest more than 5% of your stack on a set-mining opportunity except in special circumstances where you may invest up to 10%”

What exactly are these “special circumstances”? The 5-10 rule was not originally intended just for set-mining situations. It applied to any situation with a speculative hand. The “special circumstances” fall into one of two categories. Either you have excellent implied odds, or you have post-flop steal-equity.

Implied Odds

In the context of set-mining, having good implied odds means we expect to make a higher amount of chips on average when we flop our set. In situations with excellent implied odds we may be able to invest slightly more chips pre-flop and still have a profitable set-mine. According to the 5/10 rule we may be able to invest up to 10% of the effective stacks, which is roughly equivalent to a “call10” rule. But in which situations do we have good implied odds?

• Villain has a very strong range – If villain is playing a very tight range he will make strong hands more often. This means we can expect to get paid off bigger with our sets. Conversely if villain is playing a wide range, it may mean our implied odds go down. It can sometimes be acceptable to fold small pocket pairs from the blinds versus a wide button opener.
• Villain is aggressive – It may be the case that villain has a weak range, but he is the type of player who just loves to keep on firing huge bets as a bluff. You have good implied odds against these players also. Just keep on clicking the call button while letting them do what they like to do best! (bluff.) Conversely, if villain has a weak range but is also quite passive, it may not be a profitable set-mining opportunity.
• Villain has a deep stack – If we can potentially make way more than we need to post-flop, this is very good for our implied-odds. In general, the deeper the stacks, the better the set-mining opportunity. Conversely, if the stacks are shallow, we may not have a profitable set-mine.
• Villain is a fish – It may not matter that villain has a weak range if he is just going to call down 3 streets with his bottom pair. As a general rule, the worse a player is, the better your implied odds. Against better players it can be tougher to find good set-mining opportunities. They may correctly realise when you are very strong and make some hero folds. It means you will make less money on average post-flop.

Steal Equity

Steal-equity or fold-equity in this situation describes additional equity given that you might be able to get your opponent to fold post-flop when you miss your set. Steal-equity is not technically relevant to set-mining. Why not? Because the definition we gave to set-mining was calling pre-flop with the sole intention of flopping a set. (i.e not calling and then attempting to steal postflop).

If we think a little more generally about any situation where we call with a pocket pair, steal equity is important. Once again we might be able to put up to 10% of the effective stacks in the middle pre-flop – this time not because of our implied-odds, but because we think we are going to be able to steal the pot post-flop when we miss. This will usually happen because villain has a wide/weak range.

We can hence invest potentially up to 10% of the effective stacks with a pocket pair for either of the “special circumstances” mentioned in the 5/10 rule. Excellent implied odds, or excellent post-flop steal-equity. If we wanted to be technical though, calling with a pocket-pair because of your post-flop steal-equity is not technically a true “set-mine”.