Aggression factor, VPIP and YOU! How to relate the 3 "by mason55"

    • silent21
      silent21
      Global
      Joined: 08.08.2008 Posts: 1,556
      Hello everybody. Before time i had an issue with the interpretation of AF factor but an one article i found helped me alot. Recently i've found that this happens to be a problem to alot of players so i decided to share the article.

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      What is AF

      If you look at what aggression factor is in PokerTracker you'll see that it's:

      (Raise % + Bet %)
      ----------------
      (Call %)


      It's the ratio of the amount of time that a player is aggressive vs the amount of time that he's passive. It's a pretty simple concept but it's easy to misunderstand and misapply.

      How to use AF?

      Aggression factor is a unit-less ratio. It's not that useful without some other information. Just like most other things in poker, it's almost always situation and player dependent, the only exception being a player with an AF of 0.

      For example, if someone's aggression factor is 0 over 100 hands we can assume he's pretty passive. He's never bet or raised, only called and folded. If he WERE to suddenly raise us we'd be scared.

      Now let's see how AF affects our everyday decisions.

      Take 2 players. A 50VPIP and an 18VPIP. Think about the approximate handranges that they're seeing a flop with.

      50VPIP (fish):
      {22+,A2s+,K2s+,Q2s+,J4s+,T6s+,96s+,86s+,76s,65s,A2o+,K5o+,Q7o+,J7o+,T8o+,98o}

      18VPIP (TAG):
      {22+,A5s+,K9s+,Q9s+,J9s+,ATo+,KJo+,QJo}

      Now think for a second about how each of those hand ranges hits the flop. The TAG is going to be making a lot of top pair, good kicker hands, as well as sets and combo draws. The fish is going to be making a lot of top pair bad kicker and midpair type hands.

      Say these players have a flop distribution (just guessing here)

      Fish
      ----
      10% top pair
      10% middle pair
      10% bottom pair
      8% flush draw
      1% set
      1% combo draw
      60% air

      TAG
      ----
      20% top pair
      8% mid pair
      2% bottom pair
      8% flush draw
      1% set
      1% combo draw
      60% air

      Let's look at what happens when you bet into them

      TAG
      ----
      Raise: Combo draw (1%), set(1%), flush draw (8%), top pair (20%) = 30%
      Call: Bottom pair (2%), mid pair (8%) = 10%
      Fold: Air

      Fish
      ----
      Raise: Combo draw (1%), set(1%), flush draw (8%), top pair (10%), mid pair (10%) = 30%
      Call: Bottom pair (10%) = 10%
      Fold: Air


      These 2 players have the exact same AF (3) but you can see that the fish is way more "aggressive." His range when he raises you on the flop is weaker than the TAGs because his starting hand range is weaker.


      Limitations of AF

      If you look at the AF forumla, you'll realize that it doesn't include fold %. This is a pretty big limitation of AF and one that people seem to forget about. Let's change the above example a little.

      TAG
      ----
      Raise: Combo draw (1%), set(1%), flush draw (8%), top pair (14%) = 24%
      Call: Some mid pair (2%), some top pair (6%) = 8%
      Fold: Bottom pair (2%), some mid pair (6%), Air (60%)

      Fish
      ----
      Raise: Combo draw (1%), set(1%), flush draw (8%), top pair (10%), mid pair (10%) = 30%
      Call: Bottom pair (10%) = 10%
      Fold: Air

      The fish's actions haven't changed, but we've had the TAG fold some of his weaker made hands and slow down a little with his top pair hands. This is probably closer to a real distribution. Notice that AF is STILL 3! Even though we've strengthened his distribution for raising he still has the same aggression factor. This is where other stats on your HUD are going to be useful. Things like "Call continuation bet %" and "Fold to continuation bet %" will tell you whether a player with a high AF is playing raise/fold with his good hands or he's a player who bluffs with air a lot.

      Summary

      Don't look at a player with an AF of 0.8 and a VPIP of 80 and say "durrr better fold to his flop raise, this guy is passive!"

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      I hope this helps you. GL at the tables
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