One of my triple-greats which was a dead-end and which I wrote about last fall was Katherina Polak, the wife of Jan Malek of Myjava. I've been pulling the Myjava Evangelium (Lutheran) church records back on microfilm and have made significant headway on Katherina. When I engaged a professional genealogist in the late 1990s to do my principal Slovak research, he did the ancestry of all four of my great-grandparents. He was efficient and, quite frankly, a bit too methodological in his approach. No doubt this was to keep his time down. He noted baptisms and must have had a formula of when an average marriage would happen before that, etc. Sometimes ages of people are given, such as the ages of grooms and brides in marriage records.
In the case of Katherina and Jan Malek, he never found their marriage record. He extrapolated when Jan would have been born and found a likely candidate. He never found the same for Katherina. In 2003 or so, I found their entry in the 1869 Hungarian census which showed they were much older than the researcher had surmised. My great-great-grandmother Susanna Malek was born in 1852, but was the second youngest child. Using the dates of the census I easily found Katherina's baptism on 25 November 1813, the daughter of Stephen Polak and Katherine Szowiss. I also found Jan's real baptism on 8 September 1801, the son of Jan and Catherine (Marek) Malek. These dates precisely agree with the census. Jan and Katherina were much older than my researcher had surmised and Jan was a full decade older than his wife. Slightly outside the norm, but not absurdly outside the norm.
So, now I have that 3rd great solved (two more to go, but they are in Vrbovce, which was just released). I also have father's names for three of the four new parents of Jan and Katherina. Jan Malek married Catherine Marek on 20 June 1797 and he is noted as the son of Thomas Malek. Catherine's parents are not given. Stephen Polak married on 16 May 1810 to Catherine Szowiss, and both had father's named Jan. I should note that this is my second Szowiss line, but I haven't connected them yet. It would mean that my great-great-grandparents were cousins, not uncommon for any small village in Europe.