Why poker sometimes feels like a lottery: Part 2

The previous poker article was about variance in poker tournaments in general. Today, I would like to introduce The Poker Tournament Variance Simulator from website primedope.com which calculates variance for poker tournaments, MTTs and SNGs. Just enter your tournament(s), hit calculate and let the simulator do its magic. An explanation how this simulator works can be found below in my example. I picked up the daily big 109USD tournament which is on daily Pokerstars schedule. You can see the input for calculation including the explanations below.

Source: primedope.com


Players: Number of players for the tournament. I assumed 200 players (entries) for the Big 109 which is standard field during ordinary week.

Structure: How many places get paid. Standard payout table considering around 18% of players in the money.

Buyin and Fee: In any currency you fancy – buyin must be greater than zero. I used for buy in for the daily Big 109$, but for this calculator I split up the real buy-In ($100) and the fee ($9).

ROI: In percent, any value greater than -100% is ok. In the example I am assuming my real ROI which is around 25%.

How many are you going to play?: How many tournaments should be simulated. For this example I want to know what results I can expect over the course of one year. That’s 365 Big 109 tournaments within one year.

Sample size: How many samples should be simulated – higher numbers yield more accurate results, but also take longer to compute. All those numbers are derived by Montecarlo simulation, thus they are not completely accurate. But going with a decent sample size (1,000 or more) they are correct within a 2%-margin of error. I used 10 000 simulations for example in this article.


Source: Primedope.com

This distribution above shows the cumulative likelihood function for the results. In this example it shows you that more than 80% of all samples had a positive result. On the other hand almost 20% of all samples had a negative result.

20 sample tournament runs

Source: primedope.com

The graph above shows 20 sample runs from the simulation as well as the best and worst run over all samples. The best run shows you almost 60k USD profit and the worst scenario means almost 20k USD loss. Obviously this is huge statistic anomaly, however still possible.

Poker MTT Variance Statistics

Source: primedope.com

Lastly the Tournament Variance Simulator shows some interesting statistics, like your probability of loss, your 70, 95 and 99.7 confidence intervals as well as the statistical standard deviation, skew and kurtosis.
In our example, 365 Big 109s, the probability of loss is still 14% despite having an ROI of 25%. Obviously, since poker tournaments are so top-heavy it needs more than just 365 tournaments to approach to your real ROI.


As you can see variance can be a mercyless bitch. On the otherside you can be on positive side of it. Morevoer there obviously are also other tournametns on daily Pokerstars schedule so you can play lot more within one year to beat the variance in long term. Remember you will be always in profit in long run if you are good player! Only thing you have to do is grind hard and stick to your winning strategy.

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