[dfan]

Survivorship is not the reason players will tend to find approx 45% winners in pokertracker (even though that is a common misconception). It is just an artifact of the large standard deviation of poker winnings/losses in comparison to the mean differences in players long-term win rates.

Here is an analogy. Say players played a game where you drew numbers from a hat and whatever number was on it you got that many dollars if it was positive and gave that many dollars if negative. 100 players sat down with their hats and numbers. Some of these players had hats with the numbers -100 through +100 in them, evenly distributed. These are the long term break even players. Others had hats with numbers -97 through +103 (long-term winning players) while some had hats with numbers -103 to +97 (the long-run losers, you know who you are).

So these hundred player sit down with their little hats and draw out their numbers. What percentage of the winning players will be winners after 50 draws? What percentage losers? What about the break even players? The losing players? Does the distribution of long-term winners, break-even, and losing players even matter much in the outcome?

If you think about it, no matter which group they belong to (winners, losers, or break even) the % that are winners after 50 draws from the hat is going to be close to 50%. The "edge" the winners have, and the "negative edge" the losers have is so small compared to the variation that it will barely even be detectable in the chaos of the wildly swinging outcomes. Even if you increase the number of draws (hands) to 100 or 200 or even 500, the % that will be winners not be that affected by the small positive or negative edges the players have.

So why doesn't PT show roughly 50% winners? Because of rake. If the rake didn't exist, everyone's poker trackers would say just below 50% were winners.

Now if you redid this experiment but had the players make 50,000 draws from the hat instead of 50, 100, or 500, almost all the long term losers will be in the red and almost all the long term winners will be in the black. At that point things like survivorship would have an influence on your stats.