Re: Beyond Don's charts?

From Stanford Wong's BJ21

Posted by truefive on 1 Oct 1997, at 9:12 a.m., in response to Re: Beyond Don's charts?, posted by Don Schlesinger on 30 Sep 1997, at 12:41 p.m.

>Let's try to find the bankroll for, say, 10% ROR.

>B = [-(s.d.)^2 x ln r]/2ev
> = (-723 x -2.3)/2 x .2069
> = 4,019 units.

>Let's do a risk calculation with a different b.r., say, 3,000 units.

>r = e^[(-2ev x B)/(s.d.)^2]
> = e^(-1241/723)
> = e^(-1.716)
> = 17.98%

>Hope this helps.
It sure does. This is just what I need to understand. Thanks, once again. (I feel like I should have you on retainer.)

Please straighten me out on one value in each equation that I don't understand. In the first it's "ln" (I think that's a lower case letter "l" and not a numeral one). I believe r represents the risk, which in your example is 10%, so that would make ln = -23, but I can't figure out what this is and consequently don't know what value to plug in for future use.

In the second equation it's "e". I see that E (in BJA, not above, where you use ev) is = to ev but I can't figure out lower case e. I tried using the ev again in case there was no difference but it didn't provide the right answer.

Thanks again.

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