PFR a meaningless stat?

[hastijoe]

It seems to me that PFR as it is calculated in Poker Tracker (# of hands raised pre flop/total hands dealt to the player) is a meaningless stat. It is important to me to know as a measure of aggressiveness what percentage of hands entered a player raises pre flop. If a player is dealt 100 hands, playes 50 of them and raises pre flop ten times, his pfr will indicate that he is as aggressive pre flop as a player who is dealt 100 hands, plays ten of them and rasies all ten hands pre flop. One is raising twenty per cent of the hands he plays and the other is raising one hundred per cent of the hands he plays, but both will have a PFR of 10.

Table stats compound the problem by taking a meaningles per cen stat (PFR) for each player adding them up and dividing by the number of players.

I am not a statistician, or even very knowledgeable about math, and I am quite willing to be shown where I am wrong, If I am.

[Squall29]

pfr tells you the % of hands someone raises pre flop

[WhiteRider]

You're right in a way - but most people display VP$IP and PFR and the two together will show you how often they're raising out of the hands they play.
e.g. your two example players would be 50/10 and 10/10, which makes the difference pretty clear.
That said, if you wanted to see a single number for how often someone raises when they enter the pot then you could build a custom stat for that. I'm not sure that that would give you as much information as the two stats, though. For instance if you have a 10/8 player, a 20/16 player and a 50/40 player they would all have the same 'raise when entered pot' value of 0.8, but I would treat them all differently..

[hastijoe]

pfr tells you the % of hands someone raises pre flop

Did you read my post? Your statement is as meaningless as the PFR stat.

[hastijoe]

You're right in a way - but most people display VP$IP and PFR and the two together will show you how often they're raising out of the hands they play.
e.g. your two example players would be 50/10 and 10/10, which makes the difference pretty clear.
That said, if you wanted to see a single number for how often someone raises when they enter the pot then you could build a custom stat for that. I'm not sure that that would give you as much information as the two stats, though. For instance if you have a 10/8 player, a 20/16 player and a 50/40 player they would all have the same 'raise when entered pot' value of 0.8, but I would treat them all differently..

My preference is to have a true PFR% stat displayed alongside the VP$IP stat. This would give me as much information as in your example, but I would not have to distract myself from play to make the math calculations (often incorrectly) to arrive at the true PFR. I think you would agree with me that the PFR stat as calculated is meaningless when divorced from the number of pots entered.

The calculation of the PFR table stat is even more meaningless, but that is a subject for another time.

[WhiteRider]

So I guess your stat would be current-PFR / VP$IP?
i.e. number of hands raised preflop divided by number of hands played preflop.

This is really easy to build as a custom stat because we already have both of those values.
Just create a new stat (duplicating PFR would be easiest) and give it the Value Expression:
(cnt_pfr / cnt_vpip) * 100

Custom Statistics and Reports FAQ

[hastijoe]

Yes, that would be my preference.

Thank you.