Fun with variance

[AKQJ10]

I don't dare post this in the Probability forum, because I fear that running simulations to empirically demonstrate statistical theory is beneath them. But it's still fun! Especially when you're looking for ways to keep your brain engaged at work that aren't TOO obviously poker related.

So anyway, I wrote a little simulator in Python and ran it with the following tweakable assumptions:

<ul type="square">[*]mean = 1.1 BB/hr (Based on small sample from Foxwoods $2/4 and theoretical max win rate)[*]SD = 9.5 BB/hr (observed; consistent with theoretical 16 BB/100 hands)[*]session = 16 hr[/list]
Then I ran 10K sessions and collected the results by 10 BB interval.

Floor #
------ --
-130.0 2
-110.0 6
-100.0 19
-90.0 28
-80.0 41
-70.0 110
-60.0 153
-50.0 280
-40.0 418
-30.0 573
-20.0 716
-10.0 890
0.0 997
10.0 976
20.0 1032
30.0 959
40.0 839
50.0 647
60.0 469
70.0 336
80.0 209
90.0 141
100.0 79
110.0 41
120.0 27
130.0 7
140.0 3
150.0 1
160.0 1


So for example, two of the 10K simulated sessions were between -130 BBet and -120 BBet. Note that a substantial number (~10%) are worse than -30 big bets!

Anyway, I'd be happy to send the Python script if anyone wants to play with it. There's an Excel spreadsheet called swings.xls that someone posted a link to on one of the forums that does about the same thing, but prettier.

At any rate, it's fun to play around with. Hopefully it'll give me a better appreciation of how big variance is in poker.

[Hedge Henderson]

Ain't randomness interesting?

I did a similar thing with Excel just using the results from our weekly home game. It took about 15 "games" before the difference between a "good" and a "bad" player was significant, and more than 50 (over a year in our game) before the difference between a "very good" and a "decent" player became significant.

Some folks will tell me that player X is better than player Y because player X has won more money in the last 3 or 6 months. They usually have a tough time believing me when I tell them it ain't necessarily the case.

[Student]

That's an amazing revelation! I'd sure like to be able to repeat your computation, but I'm just too old for that sort of thing. But thank goodness you can do it, and you're willing to share!

Dave