600 years is 91.41% what does it mean

[Jim Denning]

i am told this would most likely be 600 yrs but this is my son so it can mean 25YEARS GET IT 25 YEARS not 600

In comparing 12 markers, the probability that James C. Denning, Jr. and James M. Denning shared a common ancestor within the last...
100 years is 33.57%
200 years is 55.88%
300 years is 70.69%
400 years is 80.53%
500 years is 87.07%
600 years is 91.41%
The above numbers are based exclusively on the comparison of their Y-DNA results, which show no mismatches.
* The FTDNATiP™ results are based on the mutation rate study presented during the 1st International Conference on Genetic Genealogy, on Oct. 30, 2004. The above probabilities take into consideration the mutation rates for each individual marker being compared.
More questions? Please refer to the FTDNATiP™ FAQ page.

[paitenceofjob]

It means that there is a 91.41 % chance of sharing a common ancestor within 24 generations. With only having taken a 12 marker test, I'm assuming this is a perfect match.

[Jim Denning]

It means that there is a 91.41 % chance of sharing a common ancestor within 24 generations. With only having taken a 12 marker test, I'm assuming this is a perfect match.

of course it is

it actually means a 91.41 chance of 25 years just as much as 600 yrs
people dont understand it can mean 25 yrs
i have a match 33/37 i beleive it works to simulair numbers we said oh and stopped talking
the same numbers
it can be 25 yrs also

[paitenceofjob]

of course it is

One can't take anything for certain. Mutations occur and fathers and sons can match 11/12 and sometimes do. But with the high percentages you were posting, I was guessing that it was a 12/12 match.

it actually means a 91.41 chance of 25 years just as much as 600 yrs
people dont understand it can mean 25 yrs
i have a match 33/37 i beleive it works to simulair numbers we said oh and stopped talking
the same numbers
it can be 25 yrs also

Jim, you asked in your thread title, "600 years is 91.41% what does it mean?" You then seem to go on to answer your own question, but there is one point concerning that answer I'd like to respond to, and that's the point regarding the twenty-five years. The twenty-five years is the number of years FTDNA decided on using for a generation. Six hundred divided by twenty-five is twenty-four. That's why I said it was a 91.41% chance of sharing a common ancestor within twenty-four generations. As you stated above there is only a 33.57 % chance of them having shared a common ancestor within 100 years (4 generations). The chances of them sharing a common anecstor within a single genration would be yet smaller. For instance, I have well over 200 exact matches on the 12/12 level. Not one of these shares a common ancestor with me within four generations, and only one does within ten. If as you say, there was a 91.41 % chance of having a most recent common ancestor within 25 years (1 generation), over 180 of the 200+ particpants who matched me 12/12 would likely share a common ancesor within a single generation; that is would be my brothers. This is definitely not the case. Now, if my son took the test, given that he did not have a mutation, he would score a 12/12 match with me as well, but he would be 1 out of 200+ particpants that I actually shared such a close connection with. He would be in that minute percentage of particpants who share a common ancestor with me within a single generation. As the generations and years roll back, more of them would fall into having a common ancestor with me. That's what these probabilities you posted reflect.

[Jim Denning]

One can't take anything for certain. Mutations occur and fathers and sons can match 11/12 and sometimes do. But with the high percentages you were posting, I was guessing that it was a 12/12 match.

Jim, you asked in your thread title, "600 years is 91.41% what does it mean?" You then seem to go on to answer your own question, but there is one point concerning that answer I'd like to respond to, and that's the point regarding the twenty-five years. The twenty-five years is the number of years FTDNA decided on using for a generation. Six hundred divided by twenty-five is twenty-four. That's why I said it was a 91.41% chance of sharing a common ancestor within twenty-four generations. As you stated above there is only a 33.57 % chance of them having shared a common ancestor within 100 years (4 generations). The chances of them sharing a common anecstor within a single genration would be yet smaller. For instance, I have well over 200 exact matches on the 12/12 level. Not one of these shares a common ancestor with me within four generations, and only one does within ten. If as you say, there was a 91.41 % chance of having a most recent common ancestor within 25 years (1 generation), over 180 of the 200+ particpants who matched me 12/12 would likely share a common ancesor within a single generation; that is would be my brothers. This is definitely not the case. Now, if my son took the test, given that he did not have a mutation, he would score a 12/12 match with me as well, but he would be 1 out of 200+ particpants that I actually shared such a close connection with. He would be in that minute percentage of particpants who share a common ancestor with me within a single generation. As the generations and years roll back, more of them would fall into having a common ancestor with me. That's what these probabilities you posted reflect.

george carlin tells the story about how he always brings his smart friends to times square when they come to new york and he has them play tic tac toe with a chicken there. the chicken always wins. all thru their stay they always want to return to play the chicken. he say its only a chicken he always wins and they scream.

i hate to bend the logic you state but this is MY SON not some stranger so why should i have to stay with the 600 which you seem to want me to


About those matches which are close maybe thier grand dads were in the navy and played around with a grand mom or two and they are four generations you and i dont know but i know he is my son
the 25 years wasnt any stupid amount of years from a math problem its the amount of years between me and my son remember its only a chicken he always wins

his 13-25 comes in two weeks if he matches me then can i cut the 600 yrs am i allowed