Shared centimorgans of half siblings down the generations

[meaty]

Hi I'd like to crack a family mystery which is answering the question of who is the father of my great grandfather. He never knew.

If this person had existing children or went on to have further children with someone other than my great grandmother, then what sort of centimorgans am I supposed to be considering in my Leeds chart?

Thanks

[Zaphod99]

Try this

https://dnapainter.com/tools/sharedcmv4

Zaph

[meaty]

Thank you that's a cracking chart. So please excuse me if this might be a daft question but to consider the CM as per my question above, and if the DNA match might be in my generation, would I be looking at the grey column on the right:
3c
73
0 - 234

or would I use the grey column on the left:
Half 3c
48
0 - 168

Many thanks

[Zaphod99]

You should consider both sides of the chart, one is for full relationships and one is half relationships. If you don't know about your ancestry, you should not rule out half relationships.

Zaph

[Biggles50]

As it is your Great Great Grandfather that you seek to identify the DNA Painter chart does not relate to Half Relationships so the data that this website will have is likely to be limited.

It does not help in that at this distance it is possible the no DNA is actually inherited and if any is inherited then the cM could be in the range 0-100cM for “Half Cousins” at the same generational level

One of the DNA tests that I manage has exactly the same problem, and unknown Great Great Grandfather.  The Great Grandmother concerned has a blank in the Birth Cert for her father and there are zero court or church records that hint at the possible Father.

With DNA the only route I used the Colour Coded Group feature that is available to go through every match with a cM of 20 or greater and assigned each to the applicable Great Grandparent of the person whose DNA I manage.

As expected there was a very large number that could not be assigned to a GGP and for the last 18 months I have been working through about 120 possibles and their shared matches.

No success so far but as I often write, DNA can be a waiting game.

[meaty]

Thanks Zaph, noted

Hi Biggles, I have 50 or so quickly made entries in my Leeds as I only went as far as 35cm - seems pretty straightforward and I only have 4 colours so it went well. To enter everyone that I share down to 20cm with would take many many hours as there are like 27 pages of matches on ancestry, it gets a bit crazy going down to those figures. That would mean I would need to add almost another 500 entries...did you have that many to do?

Another question, I found myself making my leeds spreadsheet and then adding colours to everyone on Ancestry to, in effect doubling my work and my internet is not too fast...would you contiune on ancestry or on spreadsheet, or both?

I'm not currently a member of Ancestry nor the Pro tools, but willing to join if it's worth it - Edit, of course I will join at the point when I start to check out trees etc, I was more asking if Pro tools worth it or is a must to get more than the 3 shared matches

Thanks