One of the most exciting things to happen in a hand of poker is when you hit a set. When it comes to holding low pocket pairs (deuces through sixes), hitting a set or better is the only comfortable and clearly profitable spot your will find yourself in.
It’s easy to remember the times that you have been greatly rewarded for hitting a set, but more difficult to recall those occasions where you had to check-fold. Without relying on sound poker theory, this skewed sense of a positive expectation is the most common factor leading poker players to call far too often with low pocket pairs pre-flop.
What mathematics say about sets
The odds of hitting a set are roughly 7.5:1, and the obvious reason why hitting a set is so awesome is that your equity will usually be very strong against pretty much any range of hands on the majority of flops. At the same time your hand is usually well disguised ,which improves your chances of playing for and winning a big pot.
Without hitting a set on flop, the equity — essentially the chances of winning at showdown — of low pocket pairs is not great as almost any flop, turn or river will be bad for your hand (mainly due to overcards being present), hence rarely allowing you to get to showdown. Because of this, you will rarely see a solid, winning player call a pre-flop bet with a low pocket pair to protect or realise its overall equity. The reason is almost always to try and hit a set and then play for stacks.
To make calling with a low pocket pair profitable imagine the only way to win the hand is to hit a set, therefore you need to expect a profit greater than the odds are to make your hand (7.5:1). This expected profit is also what is knows as implied odds.
Say an opponent, who you have covered in terms of chips and who you know will likely pay you off on any flop if you manage to hit your set, opens to $10 pre-flop with $100 left in his stack. The implied odds here are 10:1, since you need to risk 10 to win 100. Thee odds would allow you to make a correct call to try and hit a set.
The tricky part
In reality, it’s practically impossible to calculate your exact implied odds as this will vary mainly based on our opponents range, skills and board texture. Even if your opponent always have more than 7.5 times the amount you need to call left in his stack, it’s highly unlikely your will get action every time. This means that you actually need better implied odds than 7.5:1 to be sure your pre-flop call is at least break even.
Against an opponent you think is very likely to pay you off if you hit your set, either because his overall range is very strong and narrow or because he perhaps overvalues the strength of his hands, calling with minimum implied odds of 10:1 is fine. Being in position or with multiple callers are two other factors that can make this a clearly profitable call.
However, in many other situations you are likely losing some money calling with implied odds of 10:1. Which brings me to the next point.
Situations to avoid
Before I sum up the do’s, let’s take a look at the don’ts. Here are some situations you should look to avoid calling with a low pocket pair:
1. Being up against one or more very good opponents. This hurts your implied odds as these players will be able to get away from some strong hands when you hit your set.
2. Calling out of position. If you are calling out of position any decent opponent can easily practise pot control and keep the pot small. Calling out of position, which usually means calling from the small blind or the big blind also makes your range easier to define. From the small blind, your calling range should be quite narrow and capped. Your calling range from the big blind will be a lot wider but still capped. What this means is that when you do hit a hand and put in a raise, it becomes easier for your opponent to correctly estimate your range and potentially slow down with a strong hand.
3. Another situation to avoid is calling when you have one or more very aggressive players left to act. With a significant risk of another playing putting in another raise and forcing you to fold, calling the initial open raise with a low pocket pair should yield a negative expectation.
In all of these situations I would recommend to call with implied odds of at least 20:1. Otherwise, folding or three-betting these hands are your only good options. The additional fold equity you gain when three-betting improves the expected value of your hand, just make sure you are not trying to bluff players which will call your three-bets a lot.
Situations to look for
Conversely, what you are looking for when calling with low poker pairs pre-flop is to have the implied odds of at least 10:1, be up against either a very tight range or a weak player, preferably in position — basically the opposite of the don’t section! If this is not the case you should look for at least 20:1 in order to make a call, otherwise folding or three-betting are better options.