There is no such thing as a confidence interval for sit-n-go's.

[ericlambi]

LOL. You still haven't given one ounce of reason why anything is wrong with my calculations. Mostly because there probably isn't anything wrong with it. Your lameass bachelor's degree in "statistics" does not make you the end-all-be-all on the subject. In fact, based on your response to this post, I'm not sure you even understand what a confidence interval is. And your contention that the results in SNGs have no properties of a normal distribution is just flat out stupid.

Finally, making $7/SNG would not allow me to quit my day job. I'm not surprised that would replace your daily income though - obviously you aren't very good at statistics for a statistician.

[Grivan]

I have 100% confidence that in 400 50+5s you will be between -$22,000 and +$78,000.

[Grivan]

I aggree a statistical analysis isn't going to tell you anything if you skill is going up rapidly, but eventually you will hit a point where your skill really doesn't raise that rapidly (and I seriously doubt the average skill of opponents really changes enough to seriously corrupt events either). In the example with Tom Brady do you really think he is going to be significantly better at football next year then he was this year? Or do you think his skill has platoed?

The same situation comes up in SNGs say you are at a level where you ahve read all the book and you play 8 hours a day 7 days a week and oyu have been doing this for years. Do you really think your skill and your opponents skill are really going to be that much different tomorrow then they are today?

I admit this factor will have an effect on the accuracy of results, but there are situations where that affect can be safely ignored.

[bball904]

[ QUOTE ]
The same situation comes up in SNGs say you are at a level where you ahve read all the book and you play 8 hours a day 7 days a week and oyu have been doing this for years. Do you really think your skill and your opponents skill are really going to be that much different tomorrow then they are today?

I admit this factor will have an effect on the accuracy of results, but there are situations where that affect can be safely ignored.

[/ QUOTE ]

I'll admit that anyone falling into this category would probably be able to make the null assumption that skill is a constant and thereby be able to construct a statistically valid confidence interval for their future expectations. So, let's see... 8 hours a day, 7 days a week, for years... let's assume 4 tabling, that makes about 15,000 or so sng's a year. Does anyone have stats for 30,000 or more sng's at one level?

But then we go back to AgentSq's closing comment. Anyone that's played that many games doesn't need a confidence interval to know if they're a winner or loser.

[bball904]

[ QUOTE ]
I have 100% confidence that in 400 50+5s you will be between -$22,000 and +$78,000.

[/ QUOTE ]

Damn! My bankroll is only 12k, I guess I'll have to drop down to the 33's.

[bball904]

[ QUOTE ]
LOL. You still haven't given one ounce of reason why anything is wrong with my calculations

[/ QUOTE ]

I never claimed that there was anything wrong with your calculations. You very good with math, Jethro. Your assumptions are where you're lacking.

[ QUOTE ]
obviously you aren't very good at statistics for a statistician

[/ QUOTE ]

I'm not a statistician and I never claimed to be. I'm a poker player and I didn't need any confidence intervals to decide to quit my day job.

[Barrett's Last Privateer]

[ QUOTE ]
I agree that jcm4ccc proved that sng results can be grouped so that they will effectly approximate a normal distribution over a large number of data sets. However, he showed this using 30,000 x 25 = 750,000 sng's. That's a few more than 25.

[/ QUOTE ]

But surely in this case it's the 25 rather than the 30,000 which is important. The CLT says that the distribution of the average result of 'n' SNGs will tend to normality as 'n' tends to infinity, and jcm4ccc's experiment simply shows that the normal distribtuion is well approximated by the time 'n' reaches 25.

So to make inferences about the mean of the population (such as a confidence interval, which is obviously the main topic of this thread) we use our best estimates of the extpected value and standard deviation, and those confidence intervals are valid.

Still very wide if the sample size is only 25 games, but valid nonetheless even for sample sizes this small.

[MWC]

[ QUOTE ]

I agree the AgentSq has provided the most enlightening and most spot on correct post of this entire thread. I second his nomination. However, you didn't state his complete message. The CI's you can construct around your estimated win rate are really only valid for past results. The unresolved issue is that the uncontrolled conditions of all your future experiences are not relative to your past experiences for any confidence intervals you can construct.


[/ QUOTE ]

You're taking AgentSq's point too far. He suggests that future results may no longer be relevant as you and your opponents change through time. Clearly, your opponents do not change over time. The same mix of fish, maniacs and decent players that were there last month will be there next month and the months after that. Will your skill change over the next few hundred SNGs? Not much. Changes in your skill can, for the most part, be safely ignored. (Should I apply my current CI to predicting my SNG results during 2008? No, of course not. Will I be able to use my 2007 results to give insight into what my 2008 results will be? Almost surely.)

Anyone applying confidence intervals obtained at a certain level, say Party 33s, to predict their performance at future samples at Party 33s, can do so, well, confidently.

You seem to be saying that confidence intervals obtained in the manners described above are of no value. (If this is a mischaracterization of your position, ignore the rest of this paragraph.) This is wrong, and no one should come away from this discussion thinking otherwise. The fact that some over-interpret CIs does not invalidate their use when they are applied prudently.

[ QUOTE ]

I agree that jcm4ccc proved that sng results can be grouped so that they will effectly approximate a normal distribution over a large number of data sets. However, he showed this using 30,000 x 25 = 750,000 sng's. That's a few more than 25.

[/ QUOTE ]

No. He showed that the estimate of the average win rate approximates a normal distribution with as few as 25 SNGs. He used a simulation of 30,000 samples to display this distribution, but the fact that it is an essentially normal distribution was true before he ran his simulations. We already knew it to be true by the Central Limit Theorem.

[teatreeman]

Hi, My credential is taking AP Stat in highschool. Most of you are not understanding what a confidence interval is.

Being 99% confident that you will make -$4 to +$19 in the next 100 Sngs does NOT mean that 99% of the time you will win -$4 to +$19 in the next 100 sngs. It means that 99% of the time your methods will be efective in producing the correct interval.

Here is the definition from my Stat book.

A level C confidence interval for a parameter is an interval computed from sample data by a method that had probablity C of producing an interval containing the true value of the parameter.

A parameter is a number that describes the population (all of those sngs)

[bball904]

[ QUOTE ]
Clearly, your opponents do not change over time.

[/ QUOTE ]

First ericlambi's high school retort and now this. If you believe this statement above, fine. But I certainly do not agree. It is comments like this that frustrate me and I'll just learn to ignore them.

This is my last post on the topic in this and all other threads. Aleo, I will PM a response to you that I owe you.

My only intention last night was to blow off some steam, but frankly I've learned a lot from this thread and appreciate most of the responses very much. Today has certainly been a nice refresher in reviewing material from 15+ years ago.

The bottom line is that I'll believe what I do, and everyone else can believe whatever they want to.