I always focus on going back in time, but since I've done DNA I've reilized how little some people have done of their own trees. I even have some wonderful matches who have linked their gedmatch to wikitree, with fairly well done trees, and still cant find the connection. I'm hoping if I can trace the descendants of the 47/64 4 times great grandparents I know, I can hopefully figure out more of the matches and how they relate to me, and then use them and the unknowns to try to fill in the blanks.
It'd be lovely to knock it out in a week, but I have no idea how many offspring one 4x's greatgrandparent could be expected to produce. I also don't know how many of my 47 known are going to be in nice couples or how many will have other divorces and remarriages or spouses after the first's death. To try to estimate the work, I'm ignoring the fact that some lines have kids faster or slower than other lines. I'm also going by US numbers, as I think my 4th greats were the last ones born in the "Old Country".
Doing the math for a complete set of 60 4x's-great grandparents:
Earlist data I can easily find is that around 1850 it would be more common to have 6-9 kids in each family. My 4x's greats would be born around 1830's mostly with kids born around 1860, so 1850 may be around when they had families.
If I have 6 kids per couple (6*30) - there would be 180 in my 3x's great grandparents generation. With 9 in each family it would be 270. The average of these two is 225.
useing this for average household size, and assuming two parents for the rest of the years:
Born 1860's and having kids in 1890's, the average was 3 kids in 1890, so 225 would have 675 children to make up my 2x's great grandparents generation.
Born in 1890's and having kids in 1910's, having an average of two kids, the number doubles to 1350 in my great grandparents generation.
Born around 1910, and having kids around 1930, with an average of two kids, there would be 2700 in my grandparents generation
Born around 1930 and having kids around 1960, with an average of one kid (3.35 average household number minus 2 parents) is another 2700 in my parents generation
Born around 1960 and having kids around 1990, with an average of one kid, there should be 2700 in my generation.
Adding those all up, that's 10350 people. For now, I'm estimating I will do a month to find, add, and source descendants. I have no idea if that's reasonable or not, but I'm going with it for now. I'm guessing the last half of my and my parents generations will be alive and therefore private, possibly even the grandparents. So more realistically it'd be 2500-5000 I'm finding.