View Full Version : What is a typical SD for a losing player?

11-20-2004, 04:00 AM
Many of us have a good idea of what the standard deviation (SD) of a winning player should be. But what about for a losing player? Do they typically have a small SD? Or a very large SD?

Why is this question important? Well, here's an example. Suppose I have a SD of 5 BB/100. Then I know I'm not a winning player. How do I know? Well, for one thing, if I were a winning player, then my risk of ruin for any particular starting bankroll would be uncharacteristically low. And experience tells us that not even the experts can play poker this well.

But what about the converse? Suppose I have a SD of 18 BB/100. What is the conditional probability, given this fact, that I am a winning poker player? The answer, of course, depends on the typical SD of losing players.

We often focus on winrate to determine if we are winners. But this can take up to 100K hands or even more. What can our SD tell us about our "winner" status?