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Thread: WinnerWannabe: How do you calulate the probability of being ahead?

  1. #1
    WinnerWannabe
    Guest

    WinnerWannabe: How do you calulate the probability of being ahead?

    Isn't it something like:

    normdist(EV/SD)

  2. #2
    Don Schlesinger
    Guest

    Don Schlesinger: Re: How do you calulate the probability of being ahead?

    > Isn't it something like:
    > normdist(EV/SD)

    What is your specific question? Is it the probability of being ahead after n hours of play? At any time during those n hours? If the former, will you always have sufficient bankroll to complete the rquisite number of hours?

    Don

  3. #3
    lagavulin62
    Guest

    lagavulin62: Re: How do you calulate the probability of being ahead?

    > What is your specific question? Is it the probability
    > of being ahead after n hours of play? At any time
    > during those n hours? If the former, will you always
    > have sufficient bankroll to complete the rquisite
    > number of hours?

    > Don

    "Isn't it something like:

    normdist(EV/SD)"

    I initially took him to be a "smarta_ _", considering all the discussion with norm's distribution of TC's, frequencies, etc....but I can't make anything of (EV/SD)? he may have meant otherwise, I don't normally post this early.

  4. #4
    Norm Wattenberger
    Guest

    Norm Wattenberger: Re: How do you calulate the probability of being ahead?

    > "Isn't it something like:

    > normdist(EV/SD)"

    > I initially took him to be a "smarta_ _",
    > considering all the discussion with norm's
    > distribution of TC's, frequencies, etc....but I can't
    > make anything of (EV/SD)?

    "normdist" is the Excel function for normal cumulative distribution. Probably wasn't named after me. (Although I did develop the first spreadsheet program in the 60s.)

    > I don't normally post this early.

    I've been meaning to do a study on the value of posts based on posting times

  5. #5
    Francis Salmon
    Guest

    Francis Salmon: Formula and example

    If you know your hourly win rate (wh) and your hourly standard deviaton(sdh),the calculation goes like this for a certain number n of hours played:
    z = squareroot of n *wh/sdh
    The result z represents the number of sds and points to the probability.
    Let's make an example: wh= $100 and sdh=$1500,625 hours played.
    The squareroot of 625 being 25,we get z=25*100/1500=1.67
    1.67 sds represents a probability of 5% for still being in the red.So the probalitity for being ahead after 625 hours of play is 95%.

    Francis Salmon

  6. #6
    lagavulin62
    Guest

    lagavulin62: Re: How do you calulate the probability of being ahead?

    > I've been meaning to do a study on the value of posts
    > based on posting times

    don't ever lose your humor norm, your posts can be downright entertaining at times.

  7. #7
    WinnerWannabe
    Guest

    WinnerWannabe: Sorry Don, I should have specified

    > What is your specific question? Is it the probability
    > of being ahead after n hours of play? At any time
    > during those n hours? If the former, will you always
    > have sufficient bankroll to complete the rquisite
    > number of hours?

    I am looking for the probability of being ahead after n hours of play assuming a sufficient bankroll. I remember reading something about it in your book. I remember you saying something like "for those who are familiar with the cumulative normal distributiuon the calculation is fairly straightforward." I'm afraid everything after that was lost on me.

    I think Francis understood what I meant but, as Norm pointed out, I'm trying to put this formula in an Excell spreadsheet. I think the formula from your book would be easier to incorporate.

    Thanks to everyone for their help!

  8. #8
    Don Schlesinger
    Guest

    Don Schlesinger: Re: Sorry Don, I should have specified

    > I am looking for the probability of being ahead after
    > n hours of play assuming a sufficient bankroll. I
    > remember reading something about it in your book. I
    > remember you saying something like "for those who
    > are familiar with the cumulative normal distributiuon
    > the calculation is fairly straightforward." I'm
    > afraid everything after that was lost on me.

    > I think Francis understood what I meant but, as Norm
    > pointed out, I'm trying to put this formula in an
    > Excell spreadsheet. I think the formula from your book
    > would be easier to incorporate.

    > Thanks to everyone for their help!

    The comment is in BJA3, p. 21, with the accompanying Table 2.2. The chart on p. 148 is what is needed, after applying the approach in the book (or Francis's formula, above), to get the answer you're looking for. Alternatively, use Excel.

    Don

  9. #9
    WinnerWannabe
    Guest

    WinnerWannabe: Got it. Thanks for everyone's help!

    So I was pretty close before, but I neglected to include the number of hours. The correct Excell formula should be:

    normsdist(sqrt(Hours)*EV/SD)

    I never knew that about you, Norm. You should have named everything NormAdd, NormSubtract, and NormNormalize!

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