GENEALOGY-DNA-L ArchivesArchiver > GENEALOGY-DNA > 2010-11 > 1290223973
From: Al Aburto <>
Subject: Re: [DNA] Odds Are, It's Wrong - 5% of the time
Date: Fri, 19 Nov 2010 19:33:19 -0800
References: <F9C440A2-FC59-4A9E-AAAC-85DEE9D2FAB0@GMAIL.COM>, ,<COL115-W50D879F102DC3996D9D454A03A0@phx.gbl>,<COL118-W33D30F8531A4233CE0ED4EA03A0@phx.gbl>,<COL115-W265440F6CAC26EACE7E766A03B0@phx.gbl><COL115-W23D43856114A4E81F80053A03B0@phx.gbl>
They are independent events, the odds are the same each time.
Losing three times in a row has no bearing on what will happen on the
next trial ...
> On 11/19/2010 6:00 PM, Steven Bird wrote:
> The cumulative odds of losing three times in a row, given a 19 out of 20 chance to win on each play, are exactly what I stated. .05*.05*.05=.000125 or .00205% The odds of each chance remain 19 out of 20, but cumulative odds of winning ONE time increase. If I flip a fair coin, the chance of heads is 50/50. However, the chance of NO heads in ten tosses diminishes to 0.5^10, or .000977.
> As I indicated before, if you are unhappy with a 95% chance of being right, then change the p value to 99.7% or 99.9999%. It is strictly up to the statistician. There is nothing sacred about p=0.05
> You might be right about the double or nothing bet however. ;-)
>> Date: Fri, 19 Nov 2010 23:56:12 +0000
>> Subject: Re: [DNA] Odds Are, It's Wrong - 5% of the time
>> Uh-oh - classic gambling fallacies.
>> If you've lost twice already then the odds of losing three times in a row are just the odds of losing the third time. It doesn't get better the more you lose.
>> And a double or nothing strategy works in favour of the party who has the last word on whether betting continues or not i.e. the bookmakers& casinos.