Loss Streak Probability Calculator

Hello,

I've come across a handy loss streak probability calculator here:

sbrforum.com/betting-tools/streak-calculator/

Basically, it does this;
"Determines the probability of losing a streak of wagers over the course of a wager series of specified length."

So, given the above;

Question;

If you placed 250 bets in 1 year, each losing with a probability of 30%, what is the likelihood of losing 5 or more bets in a row at some point during the year?

Question is; How is this calculated?

EXAMPLE:
=======
Cell A1: I enter 250 (Number of bets)
Cell B1: I enter 5 (Losing Streak Length)
Cell C1: I enter 30% (Probability of loss)
cell D1: Probability Streak % Answer?

Does anybody know how to create the formula to derive the answer for cell D1 from the above criteria?

The answer is apparently 34.452%

you can probably answer that yourself based on all the information you posted. it's just reverse mathematics. like being given 2 elements in a 3-element math problem, and then using grade school mathematics to move the elements around so there is only one unknown element on one side of the equal sign. think reciprocols in fractional mathematics. that's the same concept.

have you looked here?

https://www.google.com/search?q=calc...tiple+year+bet

Originally Posted by vba_php

you can probably answer that yourself based on all the information you posted. it's just reverse mathematics. like being given 2 elements in a 3-element math problem, and then using grade school mathematics to move the elements around so there is only one unknown element on one side of the equal sign. think reciprocols in fractional mathematics. that's the same concept.

have you looked here?

google.com/search?q=calculate+probably+of+multiple+year+bet

I'm not sure it's quite that simple Adam, I've found a solution but it includes a table that calculated every eventuality then using the vlookup and match function to identify the correct value.

If your solution is possible I would much rather use it but I have limited mathematical knowledge and struggle to comprehend much of the content from the results of that google search.

well I suppose I could do a little research for you to help, but before I do, can you possibly explain why the following post on another board is literally verbatim of the words you posted in your original question this in this thread? Is this a coincidence? if it is, it's pretty strange!

https://www.mrexcel.com/board/thread...ulator.530542/

Originally Posted by vba_php

well I suppose I could do a little research for you to help, but can you possibly explain why the following post on another board is literally verbatim of the words you posted in your original question this in this thread?

mrexcel.com/board/threads/streak-calculator.530542/

Yes haha, simply because I already tried to find the answer and that was the most relevant post I could find, so I duplicated it to see if there is an "updated" solution to the problem as that post is 9 years old now.

do these examples provide something similar to what you're looking for?

Originally Posted by vba_php

do these examples provide something similar to what you're looking for?

Thank you for taking the time to make these, it looks to me as if it's on the right track, but doesn't factor in the number of bets which has a significant impact on the final result.

yeah I realize that Joe, but the number of bets is irrelevant when you're just looking for a streak of FIVE losses at any point within the 250 bets. doesn't that make sense? any given 5 losses in a row doesn't make a difference with regard to where they are in the progression of within the 250 bets total. or do they? I might be wrong. but you tell me, since it's your project.

Originally Posted by vba_php

yeah I realize that Joe, but the number of bets is irrelevant when you're just looking for a streak of FIVE losses at any point within the 250 bets. doesn't that make sense? any given 5 losses in a row doesn't make a difference with regard to where they are in the progression of within the 250 bets total. or do they? I might be wrong. but you tell me, since it's your project.

Hi Adam,

When calculating probability it increases in correlation with the number of events, an example of this would be a coin flip. We all know that a coin flip has a 50/50 chance of being heads or tails, furthermore, if you flip a coin twice the probability of landing on heads or tails is still 50/50, however, the probability of your guess being incorrect over those two flips is not 50/50 it is actually 62.5%.

It is with this understanding that I believe it is important to consider the number of bets.

J

yeah now I follow you Joe. But unfortunately it's been a while since I was in business school. I would have to look it up on the internet. I can actually give you a few phone numbers to the people who teach that stuff here at the U of Iowa where I live, but I'm guessing you don't live in the USA?

https://en.wikipedia.org/wiki/Cornwall

it sounds to me that searching that concept on google would be fairly easy. for instance:

https://www.google.com/search?q=incr...ple+coin+flips

Originally Posted by vba_php

yeah now I follow you Joe. But unfortunately it's been a while since I was in business school. I would have to look it up on the internet. I can actually give you a few phone numbers to the people who teach that stuff here at the U of Iowa where I live, but I'm guessing you don't live in the USA?

wikipedia.org/wiki/Cornwall

it sounds to me that searching that concept on google would be fairly easy. for instance:

google.com/search?q=increasing+probability+of+guess+multiple+coin+flips

Hey man, thank you for the though, however, I am indeed in Cornwall, UK.

I'll likely keep my incredibly large table for the time being, hopefully, I'll have a qualified risk analyst by the time I really need an efficient method

J

ok. sorry i couldn't help more.