Pokertracker - aggression factor useless?

[Supern]

Glad to hear from you Dad!

It seems like the only reliable stats are VPIP and PFR.
And to some extent Went to SD% to see if he is easy to bluff or not. [img]/images/graemlins/wink.gif[/img]

I agree that notes is the way to go.
If the player:
betting trips or slowplay
betting draws
bluffs alot
induced bluff
how he behaves after pf raise - bluffs on flop, turn
if he bets against a pf raiser - what hands
etc

[SackUp]

The agg. factor is actually a really good indicator, but just not necessarily on its own. You need to use the stat in conjunction with the other stats.

The other posters are correct that an AF of 1.3 may be misleading b/c a dude sees 50% of flops and is just calling so often. That doesn't mean the AF of 1.3 is off, it just means you need to account for the vpip as well. I wish I had some of the link to other discussions on this. Maybe someone has one as a favorite or can do a search for them.

But essentially you have to look at how many hands the guy is playing and then base the agg off of that. A guy who is playing 50% of hands with an agg. factor of 1.5 is betting/raising a heck of a lot more hands than a dude with 20/1.5. So you first need to look at the range of hands the guy could be on and then the aggression.

This is obviously more complex than just look at the AF and know how the guy plays...but hey it cannot to everything for you [img]/images/graemlins/smile.gif[/img] Maybe there is a way to combine the numbers into something more meaningful. If you could combine the vpip and AF numbers.

[excession]

As anyone who has read my PT articles is aware there is serious problem with the way that Aggression is calculated at the moment. Someone who checks/folds 16 times out of 20, never raises, calls once but bets out first 3 times will have a PFA of 3 for example. If you just check to him on the flop hoping that as he is 'aggressive' he will bet back at you and you can trap him, you are going to be very disappointed.

What aggression really shows is how likely a call is. A player with agression 3+ will call you rarely. One with PFA of .3 will call you down a lot.

When I was doing the last NL autorates I thought that this flaw was fatal and spent a lot of time looking for other ways of measuring true 'aggression' or the likelihhod of escalating a pot(which is really bet+raise ratio to check+fold with calls being pretty neutral) on the PT stats available for autorate. None really works in practice. Actually it is very rare that someone's aggression stats are very misleading especially after a decent number of hands - as a rule of thumb an aggressive player can be checked to and you can still expect a bet and a passive player is showing strength if he bets out and you should pick another spot to run a bluff. This means that for most situations you can still use the agression stat for what you need it for.

What it doesn't indicate so well is weakness (folds to flop bet%) but now with PAHUD you can have that stat up for all players at all times anyway (as well as cold calls pre-flop% and WtSD% which are also quite handy)

Remember you can pull the actual stats up for any player and if you are looking at a big pot it would be worth doing this - in the meantime until PT (or maybe PokerAce for his HUD) redefines aggression the current PFA ratings are flawed but still useful.

[Supern]

How many hands do you think is needed to draw any conclusions besides VPIP?
I think 200 is the minimum for aggresion and 500 for BB/100.

[Supern]

Which stats do you use?
And which ones should really be avoided?

It seems like the "bet/raised/ch-raised" and "just called" with W$SD% is a good indicator.
Or is it some kind of trouble with them?

I have to agree that the value of the AF stat is very questionable. In my opinion though, the biggest problem is that it is horribly named. I think most people would agree that in most situations raising or folding is a better option than calling; I've seen that stated as a general rule by many people and in numerous poker books. This is the general philosophy that the AF stat seems to be trying to rate. But is that truly a measure of aggression?

If you have one player who NEVER calls, their AF is infinite, seemingly indicating that they are inifinitely aggressive. But what if that person does nothing but check/fold except when they have the nuts (which they raise)? Is that person really aggressive? Conversely, you have a player who never checks or folds; they either bet, raise, or call everything and see a showdown every time. Is that person really passive?

The fundamental problem with using the AF stat for measuring aggression, is that checking and folding are not factored into the equation at all. Those are almost by definition the MOST passive actions you can make! How can you possibly rate how aggressive/passive someone is without taking their most passive actions into account? By folding you're basically saying, "I give up, you win". By checking, (unless you're slowplaying) you're saying, "My hand sucks, I'm just hoping for a cheap showdown." That's about as passive as it gets. By comparison, calling a bet seems downright aggressive. At least you're in there trying to make something happen and giving your opponent something to think about on the next street.

AF has some value in the sense that good solid players will tend to have a higer value because they're following the "fold or raise" philosophy, but that's not really a measure of aggression in my book, just a measure of solid play.

[excession]

It depends on the Vp$iP - if someone is ultra-tight (say 12% Vp$iP) then you will need 5 times as many hands to get a good read on aggression as against an Xtra-Loose player with 60% Vp$iP.

For the normal Vp$iP of 20-30% I'd say the PFA settles down somewhere in the 40-50 hand range..

[allenciox]

Ok, the real answer is that what we mean by aggressiveness is different in different situations. Once I have more than 100 hands against a player, I look at his detailed stats. Then I rate him three ways, which I put on his notes. I update this again for 200 hands, 300 hands, etc.:

checks/bets ratio: for high ratios I rate "ps" (pot stealer), for low ratios, I indicate "nops". For neutral ratios I do not indicate. A pot stealer is someone that tries to pick up pots when noone has yet shown strength.

raises/calls: for high ratios, I rate post-agg (postflop aggressive). For low ratios, I rate post-pas (postflop passive). Neutral ratios get post-neu.

calls/folds: high ratios get rated cs (callstation), low ratios get rated nocs(no-callstation). Neutrals get no rating.

Finally, I have one other measure: Based on first action after preflop raise:

bet/check: high ratios indicate con (continuation better). Low ratios are nocon (no continuation better)

It would be great if PAHUD or PT calculated these automatically, but until they do, I have to do the self-ratings.

[Supern]

I really like your idea.
What numbers do you use for your ratios?
And do you use the Total% or Flop% (too bad total includes pf)?

ps, nops, cs, nocs, con, nocon

In NL, if the AF is above a 2.0, he's probably full of it about 40 % of the time.