Possibility of losing 100 BB's in one session?

[mplspoker]

Yes, but over that period you are playing a lot more hands..... Totally different.

[OrangeHeat]

I was being facetious....

orange

[JasonP530]

Nate, how do you figure the percent of times you will lost a certain amount, based on your variance and win rate? Do you use pokerstat, or is there a formula you use?

[tpir90036]

Jason,

Do a google search or search the probablity forum for "standard deviation" and/or "confidence intervals."

cheers,
-tpir

[Analyst]

Sub-optimal play certainly makes a 100BB swing more likely, but as Nate points out, statistics demonstrate that even winning players may run into this on occasion.

At a B&M, a 20BB standard deviation seems very high, but using 12BB and a +1BB/hour win rate gives the following for an 8 hour session:

mean result: +8 BB
std deviation: 34BB

so -100BB is a 3.17SD event, or roughly one in a thousand. Far from likely, yes, but how many stories have you read hear about people getting sucked about by perfect runner-runners? Just about the same odds there.

[Senor Choppy]

1 in a 1000 assuming a win rate of 1 bb/hour and 12 bb SD. Lower his win rate to .5 bb (it is his first time playing that limit after all), and jack up his SD to maybe 15 bb or so since one guy is raising every hand, and it will be a much more common event.

[Analyst]

Much more likely, as you state. Using your numbers it now becomes a 1 in 140 event. The average win rate is actually of relatively little importance for short-term swings - at 1BB/hour, a 100BB downswing will happen once in 180 times; at 0BB/hour, it's once in 110 times, but these are players of vastly different skill levels.

For a -2BB/hour fish, this'll happen once in 44 times - almost once per year for the weekend warrior! I've seen one player at the local B&M (who may very well be even worse than -2BB/hour) go through four racks within the first hour on several occasions.

[mike l.]

"But still a product of suboptimal play and bad decisions."

that's always been a winning formula for me so i dont see why that should hurt him.

[Senor Choppy]

I'm surprised at how little win rate figures into it. Thanks for running the numbers again.

[Noo Yawk]

Hi Rushmore,

Fair enough. I was addressing a portion of his post where he twice stated he played "very Well" and "correctly".
I'm fairly positive that a first time 20-40 player that lost 100 BB's in his first 8 hr session is far from aware what correct play is. He'll get there if he wants, but not if he assumes that his 100 BB loss is excused as variance. If he sticks around this board for a year, he'll realize that.