The % of the expected down swings?(variance)

[Tharpab]

Lets your a limit player with win rate of 1bb hour
and SD of the standard people use(I believe its 16), then a normal swing would be 2SD of 32BB with 95% of chance of happening, correct?
Then how came I hear about people complaining about swings of 150BB and more, how everything is bad, whats the chance of that happening based PURELY on luck?(can that be calculated mathematicaly for an 'avarege winning player'?)
Even if his SD is 40, there is only 95% of having a 80BB, are those guys playing terribly and blaming luck?Maybe I'm just lucky, my wrost so far was 50BB

[sthief09]

16 BB SD is more likely as a SD per 100 hands than per hour. when you say a swing of 32 BB is 95% likely, that's incorrect. this is the correct statement:

given that your winrate is 1 BB/100 hands and your SD is 16 BB/100 hands, then in 100 given hands, 95% of the time you'll finish between -35 and +37 BB.

this is just given a 100 hand sample. when you start to play more hands the swings, in the big picture, will become smaller, and your winrate will approach your actual one.

[danderso8]

There is a 95% chance that in ONE HOUR OF PLAY the player's bankroll would change by +1 +/- less than 32BB. If he plays, say, 1000 hours, then you would expect 50 of those hours to fall outside 2SD, with about half of those on the negative side. If he happens to put a few of the outliers (either positive or negative) in a row (along with maybe some neutral hours in between), voila, Big Streak.

While it's possible to experience a swing (up or down) of 150BB in one hour, that's not what people are generally saying when they talk of those streaks. Those are usually much longer in time than one hour.

btw, posts like this one will generally get more responses in the "poker theory" forum.

--Dan

[dogmeat]

I'm not sure about the SD you are using, but the higher your win rate, the lower your SD. Now from that number, each "hour" of play is independent of the last - this means it is easy to have a couple (or more) losing sessions, and a 150BB swing is quite possible. The more aggressive you are during a downswing, the more volatility you will have.

You have to understand what your win rate really is. Suppose you have been winning 1BB per hour. If your SD is 10BB and the SE (standard error) pertaining to your hourly rate is equal to SD/sqrt(n) where n=hours played, then you will find that after 400 hours to achieve a 90% accurate view of your win-rate it will be within .8 BB This means if you are playing $5/$10 and want to know with 90% accuracy what your long-term win rate is, it is somewhere between $2 and $18. The long run is a looooong time.

Dogmeat /images/graemlins/spade.gif

[Griffin]

[ QUOTE ]
16 BB SD is more likely as a SD per 100 hands than per hour.

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What is a good SD per hour? Mine is about 12 to 14 bb/hr at pacific 2/4 and 3/6. Pacific averages about 50 hands per hour. Do I have too much variance in my game?

[sthief09]

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I'm not sure about the SD you are using, but the higher your win rate, the lower your SD.

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your SD is independent of your winrate. I think you're thinking of the fact that a higher winrate requires a smaller bankroll. that's just because your lows won't be so low. with a winrate of 5 and a SD or 16, the -1 SD is -11 BB. with a winrate of 1, it's -15 BB.