[BruceZ]

[ QUOTE ]
using excel, i entered 200 cells of =NORMINV(RAND(),3,30)

i believe that generates a random distribution of numbers which would imitate that of a player who's winrate is 3bb/100 and has a variance of 30bb/100. i'm not sure if that variance is accurate for a typical player, its what i remember mine to be.

200 cells means 20,000 hands. the average winrate after that many hands is 600bb. here's a list of trials of actual wins:

648
1659
1357
730
1117
1000
707
-394
1421
494
356
371
826
919
1393
523
209
767
717
240

that's ONE losing streak after 20,000 hands out of 20. how can people say that good players still have 100k hand breakeven stretches?

so is this experiment not accurate for some reason? or are all downswings a result of bad play moreso than bad luck?

[/ QUOTE ]

You would expect about 1.6 out of 20 on average, so your results are just a little lucky, but still in line with expectations. The average win rate for 20,000 hands is 3*200 = 600, and the standard deviation for 20,000 hands is 30*sqrt(200) =~ 424. So being negative after 20,000 hands is about 600/424 standard deviations below average, which corresponds to a probability of 1 - NORMSDIST(600/420) =~ 7.85%, or about 1.6 in 20.

Repeating this for 100,000 hands would that show being behind after that many hands would be more than 3 standard deviations below average, and the probability comes out to about 1 in 1278. So while rare, this is still possible.



[ QUOTE ]
also, if my variance is 30bb/100, what's my variance per hand? do you just divide by 100?

[/ QUOTE ]

That is the standard deviation, not the variance, and you would divide by sqrt(100) = 10.

The variance is the square of the standard deviation, 900 bb^2 for 100 hands, and if you wanted the variance per hand for some reason, then you would divide this by 100 hands.

EDIT: Changed NORMSINV to NORMSDIST