Estimating the accuracy of an opponent's VPIP value

[mack848]

If your PT stats indicate that an opponent has a VPIP of 30% after 100 hands, how might you go about asigning confidence limits to this?

It's not that I am particularly interested in knowing this on a player-by-player basis, but that I am interested in finding out the likely level of precision for different numbers of hands and VPIP values. Should I take any notice of a VPIP value after 20/50/100/500 hands?

Clearly, the more hands you have, the more confident you could be that the VPIP accurately represents a players true VPIP.

Similarly, I assume that the lower the VPIP, the narrower the confidence interval would be?

[Paul2432]

A reasonable estimate is to take 100%/sqrt(number of hands). The given VPIP should be within +/- the calculated value about 95% of the time.

For example after 100 hands you know the VPIP within +/-10% with 95% confidence.

Paul