Out Play Your Opponents by Using PokerStove

Part 2: VPIP/PFR is not the same as PokerStove's top N% of hands.

From the PokerStove FAQ:

The slider interface for setting the top N% of hands orders the hands according to their preflop all-in equity versus three random hands. This rather arbitrary selection was picked because it balances the value of high cards with the value of drawing cards. It is not an absolute ordering, and depending on the specific situation you may want to edit that range of hands when doing equity calculations.

I often see people taking a number from their HUD, sliding PokerStove's hand percentage indicator over, and using that to determine Villain's range. Hopefully this post illustrates the error in such an approach. Let's say an aggressive Villain has an UTG PFR of 17%. Using PokerStove's slider:

Let's revisit our aggressive UTG raiser from the previous page:

In both examples Villain is raising the exact same 17.3% of hands from UTG, but we see two very different ranges. So what is the significance?

Let's say that Villain raises UTG and we flat with T 9. The flop comes K T 4 and he leads out (we expect him to do this with his entire range). How does our hand fare against his range?

Against PokerStove's default 17.3% of hands we have 43% equity:

With position and pot odds we can call, but we're not loving it. If Villain barrels a lot then calling actually becomes a bad play. Perhaps flatting his UTG raise with T9s was a bad idea in the first place.

Against Villain's true 17.3% range our equity is a much-improved 53%:

Now we are actually happy to call and our preflop flat makes a lot more sense.

This is just a single simple example. Many more complex, more interesting hands will come up where it is very important to get as close as possible to Villain's actual range of hands. Sometimes it may even be necessary to determine if a specific hand is even in a Villain's range, for example if he is repping a very specific hand on the river. The first step in accurately determining a hand range is to get it right preflop, and if you're relying on PokerStove's top N% of hands, you're already making a small mistake.