Gedmatch results don't tally

[Old Bristolian]

I'm not sure what the problem is with the following, but perhaps someone could suggest an answer as I am a complete novice with DNA genealogy.
I have a contact in the States who is a possible cousin, based on paper research; there is a missing baptism which prevents us from being sure about this. We have both recently taken DNA tests, myself with Ancestry and her with 23 andMe, and have both uploaded our data to Gedmatch. On checking the  multiple kits tool (her father has also done the same tests so there are more than just the two sets of data) she finds that there connections between our DNA results indicating we are cousins in roughly the degree we had anticipated. On the other hand, when I carried out the same test the results came back that I have no links at all with her data - no segments in common, no shared cM etc. How can this be?

Steve

[Mart 'n' Al]

Did both tests use the same SNP and cM settings? This article explains that some threshold defaults vary.

https://dna-explained.com/2016/03/30/concepts-centimorgans-snps-and-pickin-crab/

Read just after the photo of hurdles.

Martin

[Old Bristolian]

Thank you Martin,

I have changed the threshold setting on the tool in question and come up with the same results as my cousin (now proved?). It does strike me as odd that the default settings on a site like Gedmatch would be such as to inhibit the connecting of 4/5th cousins,

Steve

[hurworth]

According to ISOGG you have about a 50/50 chance of matching a 4th cousin.

https://isogg.org/wiki/Cousin_statistics

I've seen it in my family.  Some of us don't match our fourth cousins, but others do.

[Mart 'n' Al]

Steve, I am delighted to have helped.  In prep for my DNA test I have spent two weeks on research, before which I hadn't heard of cM nor SNPs!

Martin