Archive for December, 2009

Date: December 20th, 2009
Cate: letters

Pokeit Letter #4 – What is the Probability of Getting Head on First Try

Mustafa_1

This question, posed to a class full of undergraduates, wasn’t interpreted quite the way Mustafa had intended. At the time, I was taking Stat 10 to satisfy a pre-requisite for my hastily put together plan to switch majors and apply to UNC’s business school. See, it turned out that physics just wasn’t my calling. Perhaps it was Dr. Yu Wu’s prickly demeanor in Physics 26, or the fact that Dr Hernandez in Physics 27 was an asshole. Whatever it was, my grades in physics had not been compelling. By the time the second Physics 27 midterm rolled around, knew I had to stop griding glass into my eyes. I spoke with my academic advisor, and by the end of the day, I had signed up for STAT 10 and ECON 10 in the Spring. Next semester, Mustafa Tural introduced me to statistics.

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Date: December 13th, 2009
Cate: papers

Pokeit Paper #1 – Quantifying the Bias in Observed Hands

We are all familiar with idea that the distribution of hands shown at showdown is different from the distribution of all hands dealt. The specter of this bias has confounded the poker botting community and lead many to eschew estimating hand ranges all together. While my scouring of the pokerai.org archives was not totally exhaustive, I don’t believe that anyone else has tried to quantify the bias in showed hands in a systematic way. In this analysis we will use a two econometric models, one created from a dataset revealing every hand, and the other from a dataset limited to hands showed at showdown, to predict a player’s hand range distribution in several different game states. By comparing the showdown equity of the match-up between an arbitrary hand and the ‘all hands’ and ’showed’ hand range distributions, we can estimate the bias in terms of its affect on showdown equity. In a meta-analysis of +45,000 game states, equity estimates derived from the dataset limited to hands showed at showdown were -1.34% ± 2.1% lower on average than those derived from the full dataset – indicating a slight upward bias in the strength of observed hands.

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Date: December 2nd, 2009
Cate: letters

Pokeit Letter #3 – Cum hoc ergo propter hoc!

xkcd

There’s this great story one of my economics professors use to tell in order to illustrate that “correlation does not imply causation”. It’s most certainly false but it goes like this. The setting is 16th century Russia, during the latter half of Ivan the Terrible’s reign. In general, this was not a great time to be living in Russia. A combination of drought, famine, Polish-Lithuanian raids, Tatar invasions, and the sea-trading blockade carried out by the Swedes, Poles and the Hanseatic League had devastated the country.  On top of that, a particularly nasty epidemic of the plague was killing between 600 and 1000 people every day.  It was not known at the time how the plague spread, so efforts to fight it were subject to wild theories. Ivan, mentally unstable and physically disabled, suspected treachery. To prove it, he had his advisors gather statistics on the number of doctors and the number of dead throughout his Kingdom. Once it was discovered that regions with more doctors also had more deaths, Ivan rounded up all of the doctors and had them executed for treason.

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