2026 Ancestor Score Completeness Statistics

Geneanet defines the Ancestor Score as 

“comparing the number of possible ancestors 

with the number of identified ancestors ”.

Inspired by the Ancestor Score - or “Completeness Statistics” - of other blogs and GeneaNet's definition above, I generated my first one in February 2016. Since then I haven't just been able to linearly increase my known ancestors. Instead, I had to remove a whole line of wrong ancestors in 2018. I could partially replace them by already existing ancestors - due to inbreeding among my ancestors.

Therefore, I decided to generate a new in-between ancestor score in August 2018 to be able to continue this series of posts (and removed the wrong one of 2017). Since then I've been gradually able to increase my number ancestors.

The generation with the most known ancestors is the 13th generation with just 21% of the theoretically maximum number of ancestors in that generation. In the 12th generation I've found 41% of the theoretical maximum (if there wouldn't be inbreeding).

Composition and Bandwidth of various Generations
Gen	Composition								Bandwidth **
	Men	Women	Total	% 2026	% 2024	% 2022	% 2020	% 2018*	% 2016	From	Until
G 3	2	2	4	100.0	100.0	100.0	100.0	100.0	100.0	1892	1906
G 4	4	4	8	100.0	100.0	100.0	100.0	100.0	100.0	1850	1880
G 5	8	8	16	100.0	100.0	100.0	100.0	100.0	100.0	1804	1857
G 6	16	16	32	100.0	100.0	100.0	100.0	100.0	100.0	1756	1832
G 7	30	30	60	100.0	93.8	93.8	93.8	93.8	93.8	1724	1802
G 8	59	59	118	118	92.2	92.2	92.2	92.2	90.6	1680	1777
G 9	114	113	227	88.7	88.7	88.7	89.1	88.3	86.7	1645	1749
G 10	209	203	412	80.5	79.9	80.1	79.7	78.7	76.4	1600	1722
G 11	348	319	667	65.1	64.5	64.4	61.8	60.8	57.0	1560	1695
G 12	454	395	849	41.5	41.4	41.0	38.4	37.3	33.8	1510	1666
G 13	493	375	868	21.2	21.1	20.0	18.7	17.9	15.7	1505	1645
G 14	456	318	774	9.5	9.3	9.0	7.3	7.1	6.1	1440	1625
G 15	351	226	577	3.5	3.4	3.2	2.3	2.0	1.6	1440	1580
G 16	217	129	346	1.1	1.0	1.0	0.6	0.6	0.5	1395	1540
G 17	119	64	183	0.3	0.3	0.2	0.2	0.2	0.1	1365	1500
G 18	77	41	118	0.1	0.1	0.1	0.1	0.1	0.0	1335	1470

     *) The years 2016 and 2020 feature an ancestor score of February; 2018 has an August score; 2022 and 2024 have a January score. 

   **) The Bandwidth of a generation is determined by the earliest and latest known birth or baptism date within that generation. 

   ***) I have many ancestors in places like Sint Anthoniepolder, 's-Gravendeel, Wieldrecht and Hendrik-Ido-Ambacht, where pre-1800 baptism records are (mostly) missing.