By June Pelo.
In the best of all worlds, genealogically, I estimate that one would have about 16,777,216 grandparents going back 25 generations. So I sat down one day and figured how many grandparents I could find and how far back I could go. The results were just a drop in the bucket. Out of a possible 65,536, I found 502 grandparents in 17 generations.
For the first 6 generations I found 60 grandparents out of a possible 60, but from there on the numbers dwindled.
The chart below shows the next 11 generations, how many grandparents were found and how many grandparents were possible: 
The last three were born in the 1400’s and I doubt that I’ll be able to go farther back because during the Stora Ofreden many church records in Finland were destroyed or misplaced.
It would be interesting to know of any readers who have been able to find records in Finland beyond the 1400’s. I’d like to hear from anyone who has gone back more than 17 generations.