2026 Ancestor Score Completeness Statistics

Geneanet defines the Ancestor Score as 

“comparing the number of possible ancestors with 

the number of identified ancestors on a 10-generation report”. 

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.

Edouard Joseph Groteclaes (1831-1893) was naturalised as a Dutch citizen

Edouard Joseph Groteclaes was born on 15 October 1831 in Hombourgh. This Belgian village is located near the borders of both The Netherlands and Germany. His parents are farmer Theodoor Groteclaes and his wife Maria Anna Duijckaerts.
At the age of 28, farmer Edouard Joseph Groteclaes married 39-year-old Maria Gertrud Lucia Scheepers on 23 May 1860 in Itteren, Limburg, The Netherlands. Their daughter Maria Anna Clara Groteclaes was born in Itteren on 15 January 1862. She was just 17 years old, when she married Alexander Hubert Smeets (1852-1941) on 18 November 1879 in Itteren. They had issue.

Nederlandsche Staatscourant, 25 July 1869: Naturalisation of Edouard Joseph Groteclaes

Born in Belgium, Eduard Joseph Groteclaes was naturalised as a Dutch citizen on 15 July 1869.
Edouard Joseph Groteclaes died, at the age of 61, on 21 January 1893 in Itteren. His widow, 78-year-old Maria Gertrudis Lucia Scheepers, died in Itteren on 3 March 1900, aged 78.
Their daughter Maria Anna Clara Groteclaes was 82 years old when she died in Itteren on 27 December 1944. Her eldest daughter Maria Anna Hubertina Mélanie Smeets (1881-1972) was to reach the age of 91.

Sources: WieWasWie.nl, Delpher.nl (newspapers), HistorischCentrumLimburg.nl.

Johan Simon Alexander Broertjes (1839-1903) was an illegitimate son

Johannes Simon Alexander Broertjes was born in on 8 August 1839 in The Hague as illegitimate son of cleaning woman IJda Holderman. His surname was changed from Holderman to Broertjes when 44-year-old IJda Holderman married 33-year-old Pieter Broertjes in The Hague on 6 March 1850. At the marriage ceremony the couple acknowledged 10-year-old Johannes Simon Alexander as their son. Until recently, however, Pieter Broertjes had been living in Alkmaar, so it's very unlikely that he was the boy's biological father.
Earlier, IJda Holderman had given birth to another son (in 1845) and a daughter (in 1836), but they had both died as babies. IJda's parents are Pieter Holderman and Alijda Sikkes. IJda died on 23 January 1882 around 20:00 at the age of 76. At the age of 73, Pieter Broertjes died in The Hague around 6:30 A.M. on 14 February 1890. His parents are Gerrit Broertjes and Neeltje Nol.

Johannes Simon Alexander Broertjes and his first wife had a surviving son

Johannes Theodorus Broertjes was born in Rotterdam on 25 May 1874 as the only surviving child of Johannes Simon Alexander Broertjes and his wife Josina Catharina Blekxstoon (a descendant of the Blackstone family in Dordrecht). Josina Catharina Blekxstoon was born on 27 August 1838 in Rotterdam, and died there on 6 May 1893. Her parents are Maria Elixabeth Hek and Johannes Blekxstoon , who is a son of Josina Wielandse and Johannes Adrianus Blekxstoon.
At the age of 34, Johan Simon Alexander Broertjes had married 35-year-old Josina Catharina Blekxstoon on 27 August 1873 in Rotterdam. Josina Catharina died on 6 May 1893 in Rotterdam, aged 54.

Johannes Simon Alexander Broertjes, widower of Josina Catharina Blekxtoon, married Carolina de Knoop

On 2 August 1893 in Rotterdam widower Johan Simon Alexandermarried his second wife, 39-year-old Carolina de Knoop (1854-1931). At the time his son Johannes Theodorus was 19 years old. In his father's opinion, Johannes Theodorus was a spendthrift, as the advertisement below shows: “WARNING. Please do not give MONEY or GOODS to my under-age son J.Th. Broertjes, as I will not PAY for it.”

Rotterdamsch Nieuwsblad (newspaper), 14-4-1894

With his second wife Johan Simon Alexander Broertjes had an additional son, Andries, who died as a baby. Their daughter Johanna Maria Broertjes was born on 15 July 1895 in Rotterdam. Johannes Simon Alexander Broertjes died in Rotterdam on 9-12-1903 at the age of 64. His only surving daughter Johanna Maria was to married Matthijs van den Berg in 1918, but died on 25 October 1920 at the age of 25. She left behind a daughter named Macheltje van den Berg.

At the age of 28, on 28 May 1902 in Rotterdam, Johannes Theodorus Broertjes married Johanna ten Westenend. She was born on 27 Septeber 1873 in Nijmegen. Her parents are Anna Kuiten and coachman Petrus ten Westenend. Johanna and Johannes Theodorus had children named Johannes Simon Alexander, Johanna Josina and Johannes Franciscus.
Johannes Theodorus Broertjes died on 16 November 1953 in Renkum, aged 79. His widow, Johanna ten Westenend, died in Zaandam on 13 May 1964.

Arnhemsche Courant (newspaper), 22-5-1947

Sources: WieWasWie.nl, Delpher.nl, HaagsGemeenteArchief.nl, Archief.Zaanstad.nl, StadsArchief.Rotterdam.nl.
For additional information, see also: StamboomDeKnoop.nl.

Two short marriages and a drowning

Michiel Christinus van der Steen was born in Gouda, Holland, on 11 December 1829 as son of Johannes van der Steen, a ropemaker's apprentice, and Teuntje Lourier. Michiel Christinus had siblings Johanna and Johannes.

Gouda

At the age of 23, on 12 October 1853 in Gouda, Michiel Christianus married 27-year-old Maria van Vliet. She was born on 3 January 1826 in Noord-Waddinxveen as daughter of Jacobus van Vliet (†1852) and Margarita Middelkoop (1797-1869). After just 5 months of marriage, Maria van Vliet died on 29 March 1854 in Gouda, aged 28.

The next year, on 9 May, 25-year-old Michiel Christianus remarried in Gouda. His new bride was 27-year-old Catharina Johanna Lansmans. Just 3 months later, on 24 August 1855, Michiel Christianus died at the young age of 25.

The widowed Catharina Johanna Lansmans was born on 12 September 1827 in Gorinchem as daughter of Gerardus Lansmans (†1853) and Dingena (“Digna”) Hitters (†1867). Catharina Johanna was a widow at the age of 27.
At the age of 30, Catharina Johanna married 22-year-old Gijsbertus van Vliet on 17 February 1858 in Gouda. Gijsbertus was born on 25 January 1836 in Gouda as son of Catharina Achten (1811-1849) and bread baker Leendert van Vliet (1812-1846). Gijsbertus had become an orphan at the age of 13.

Gijsbertus van Vliet and Catharina Johanna Lansmans had 5 children:

Leendert Schenk

1. Catharina Dingena was born on 23-9-1860 in Gouda. At the age of 19, she married 24-year-old Cornelis Schenk. He was born on 14-8-1856 as son of Dirk Schenk (1822-1872) and his first wife Maria Elselina van Omme (1824-1862). Cornelis Schenk died on 15-4-1950 in Gouda at the advanced age of 93. Catharina Dingena died on 7-4-1931 in Gouda, aged 70. They had children, including a son Leendert Schenk (photo to the right).
2. Dina was born on 1-2-1864 in Gouda, and died there on the 3rd, 2 days old.
3. Maria was born on 1-2-1864 in Gouda with twin Dina. Maria died in Gouda on 11-3-1864*, 1 month old.
4. Leonardus Gerardus (photo below) was born on 16-2-1865 Gouda. In 1901 in 's-Hertogenbosch, he was convicted of vagrancy. He was send to a reform housing colony for the poor and homeless in Veenhuizen. Leonardus Gerardus died, at the age of 79, on 26-1-1945 in The Hague.
5. Theodora van Vliet was born on 25-3-1870 in Gouda, and died there on 1-5-1877, at the age of 7.