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Big-Y Matching results

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  • Big-Y Matching results

    I am L48 positive and also S21809 positive. I know for a fact based on previous HG19 U106 analysis that I should have 557 matches at L48 and 5 matches at S21809 yet my matching results show a big zero for all 5 levels.
    I realize FTDNA has things they need to fix in their matching database but why can't they give the customers some periodic feedback on when we might expect to see matching results?
    Another haplogroup which I have tested cousins (Z18) at least has some matches showing. But even there (Z18) we should see 192 matches yet only 7 are showing.

  • #2
    I went from 19 matches down to 5 but most of the 19 were quite distant. The new matching guidelines are much tighter now. I would have expected to see at least 7 matches though so I think the new guidelines are too tight now.

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    • #3
      same for me I had several matches for my Big Y results then since I have ZERO Match . I had No explanation.this is very annoying. I don't care to have 500 Y-Strs.
      Last edited by FredH; 20 April 2018, 01:23 PM.

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      • #4
        Same here, I lost all my BigY matches.

        Supposedly it comes from the fact that ftdna has increase the stringency to qualify as a match to a maximum difference of 30 novel SNP, total, between the two kits.

        At 100-120 years per SNP, and assuming each kit has 15 difference with the other, it put the Most recent Common ancestor at 1500 to 1800 years.
        For anglo customers it is a OK, because of the founder effect in the relatively small British isles, any British man testing (including the American colonial) has very good chance to have a MRCA with any other Brit man within this 1500-1800 years time frame, but for the Europeans men not confined into 'small' island, with ancestors spread on a larger area, the testing sampling must result in lower chance to get this 1500 years old MRCA.
        For example, assuming that 1500-2000 years ago my ancestor was in Eastern Europe, and/or did not enjoy a massive male population expansion with no subsequent immigration in the US, it is easy to understand that my chances to find a match are reduced compared to a Brit or colonial.

        In my opinion, to be fair to all customers, the stringency should be relaxed by 500 years at least, to 2000-2500years MRCA. I think it was actually the case that FTDNA wanted to use initially a max difference of 40 SNPs to qualify as a match. I don't know why they reduced to 30SNPs.
        After that we can always look where is this match in the Haplotree. I assume that anybody who takes the expensive BigY is smart enough to understand the Haplotree.

        With a bit of luck, FTDNA will read these complains and relax a bit the stringency. Otherwise the new BigY interface and the new 500 STRs are totally useless (nobody to compare to) for those with zero BigY matches.

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        • #5
          Originally posted by Ric View Post
          Same here, I lost all my BigY matches.

          Supposedly it comes from the fact that ftdna has increase the stringency to qualify as a match to a maximum difference of 30 novel SNP, total, between the two kits.

          At 100-120 years per SNP, and assuming each kit has 15 difference with the other, it put the Most recent Common ancestor at 1500 to 1800 years.
          For anglo customers it is a OK, because of the founder effect in the relatively small British isles, any British man testing (including the American colonial) has very good chance to have a MRCA with any other Brit man within this 1500-1800 years time frame, but for the Europeans men not confined into 'small' island, with ancestors spread on a larger area, the testing sampling must result in lower chance to get this 1500 years old MRCA.
          For example, assuming that 1500-2000 years ago my ancestor was in Eastern Europe, and/or did not enjoy a massive male population expansion with no subsequent immigration in the US, it is easy to understand that my chances to find a match are reduced compared to a Brit or colonial.

          In my opinion, to be fair to all customers, the stringency should be relaxed by 500 years at least, to 2000-2500years MRCA. I think it was actually the case that FTDNA wanted to use initially a max difference of 40 SNPs to qualify as a match. I don't know why they reduced to 30SNPs.
          After that we can always look where is this match in the Haplotree. I assume that anybody who takes the expensive BigY is smart enough to understand the Haplotree.

          With a bit of luck, FTDNA will read these complains and relax a bit the stringency. Otherwise the new BigY interface and the new 500 STRs are totally useless (nobody to compare to) for those with zero BigY matches.
          And then it would be very nice to be able to select the value of the difference. For example, in the range of 24-40 SNPs, with some limits on the number of reported matches or a limit on the number of SNPs given the number of reported matches.


          Mr. W.

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