Interpretations needed for 21/25 match (J2)

[attock1881]

I do understand that a 21/25 match doesn't count for much in y-dna paternal line testing, but this is in fact the closest match i have on the entire database. So i hope you'll forgive me for reading a little more on the match..

I did a 67 marker test, and thus far, only the first 25 have returned back to me, and i've just been doing a preliminary examination of the results. I've been wondering about the possibility that me and this match sharing a common ancestor. If we do have a common ancestor, then how far back would that have been?

Here's the comparison chart provided by FTDNATIP:

"In comparing 12 markers, the probability that Mr. xxxxxx and yyyyyy shared a common ancestor within the last...

Generations/Percentage
4 6.67%
8 18.94%
12 32.64%
16 45.68%
20 57.13%
24 66.71%
28 74.48%"

Our mismatched markers are mostly found on those with faster mutation rates:

DYS: mine/his
439: 12/11
458: 18/17
449: 31/33
464: 12-12-14-15/12-14-15-16

QN: How many generations back will a perfect match of 25 and 37 markers bring you? Does it differ from one Haplogroup to another? (i've seen a two individuals from Haplogroup G having a 25/25 match. The paper trail proves their MRCA is about 20 generations back)

Here's hoping someone experienced in the J2 or G haplogroup can provide some answers. Thanks!

[nathanm]

21 of 25 isn't a very close match at all. I know it's frustrating to have few or no matches, but be patient. Maybe you'll have more by the time you get results for all 67 markers. I have four perfect matches at 12 markers, one of which has a GD of 2 at 25 markers, then increases to a GD of 4 at 37 markers.

Another possibility is some people set their preferences to only match those within projects they're members of. Don't ask me why, since I want to find as many matches as possible. So one way to find those people is to join as many projects that are applicable to you. You should be able to find a similar surname project, plus projects for your haplogroup and the geographical area your ancestors lived in. Then, when you select one of the projects in the top of the left column on the My FTDNA page, it will match among members of the project you have selected.

[ragnar]

Which one are you & your match? G or J2?

[attock1881]

Which one are you & your match? G or J2?

We're J2..

I was just quoting the example of two Gs i saw who were perfect 25/25 matches even though their MRCA was 20 generations ago..