My bad...I forgot to divide the confidence level in half so it is actually 250 / 1. OOPS

edit: bah...not worth it. Enjoy!

Here is what I have observed about variance and ascertained from comments of others:

A good player can expect to "run bad" or be -bb/100 for as long as 20,000-30,000 hands every several hundred thousand hands or so. It doesn't matter if you are Wintermute or Rainaruby.

How useful is this knowledge? I'm not sure. Obviously you never know how long "running bad" is going to last, a day, a week, or a month. It does provide some perspective in why it is important not to chase bad sessions-- because luck does not have to "even out" for a very very long time. It is also helpful to avoid losing your confidence and altering your play too much.

Going back over my results for the year, I STILL have trouble accepting that I am going to lose money-- and sometimes a decent amount-- every 3rd or 4th day, because when you win for several days in a row, it doesn't seem like you should ever lose. Personally, I start to lose touch with reality after winning for 7+ days in a row. To me understanding variance is just a coping mechanism for those of us that find losing insufferable.

One more thing: In my opinion, for the most part, for a good player, there are predominantly 2 kinds of luck that you will observe with any frequency, 1) bad luck and 2) normal luck. "Good luck" should not be something that you experience very often in the obvious sense.