[quote]

*Originally posted by grohon69*
*Originally posted by getdotacom*
[QUOTE]Holdem manager give u std dev stat, if u don't have samplesize, it usually will be something like 8.5-9.5bb/hand.[/quote]

could you please explain/interpret this figure in english. lets say in 1m hands you have std dev of 9bb/hand[/quote]A standard deviation is a measurement of variance. It's symbol is σ, called sigma.

Let's say you are a great player and expect a winrate of 10bb/100. A common standard deviation for a NL 6 max player would be something like 95bb/100.

In a normal distribution (the bell shaped graph) 68% of the time you will fall within 1 standard deviation of the mean (your expected winrate 10bb).

95% of the time you will fall between 2 standard deviations from the mean

99.7% of the time you will fall between 3 standard deviations from the mean.

Imagine each dot in the colored part of the bellshaped graph a 100 hand sample out of billions of hundred hand samples.

i.e. if 1 sd = 95,

over 100 hands you can expect:

- 68% of the time you will will end up with a winrate between 105bb and -85bb

- 95% of the time a winrate between 200bb and -180bb

- 99.7% of the time a winrate betwee 295 and -275bb

Now, what we can do something called a monte carlo simulation which is basically sticking a bunch of these 100 hand samples together randomly. Do it something like 10,000 (100k hands) times.

Then do it again and again (keep hitting that calculate button) and again and again and... well you get the point. And you can see different possible journeys.

You can also plug in different winrates and see how dramatically that changes things. You definitely should do it with 5bb/100 and 3bb/100.

There you go. Now you understand NL poker variance.

The tldr version is, when people ask you how much you made playing poker. Don't tell them a sum. Tell them, 'my hourly is x with a standard deviation of 9x'. And then wait. They will either happily say 'nice hourly, good job', and you leave it there. Or if they've done some stats, their eyes will light up and they'll understand.