My two cents...
In additions to "healthy lines", some dogs are very interesting because of the diversity they are carrying and they can bring into the breed. As we saw for exemple for Wilk/Hamlet --- Radov Dvor---, which belong at the moment to the very top of interesting dog regarding diversity. One can use mean kinship coefficient to have an idea of the level a dog is interesting (regarding diversity), quoting
John Armstrong:
"A conservation biologist would consider the individual with the lowest mean kinship to be the most genetically valuable in terms of maintaining diversity in the population, and would try to favor that individual in a breeding program. ".
[NB: we need to compare to all other living dogs so the calculation can be heavy, so one would need to use a dedicated tool for this.].
In the breed there is also something "singular", the use of last introduced wolf line. If I understood well, Slovak breeders did not use much this line compare to Czech (and then Czech breeders needed to use much two dogs -Gar z Rosikova and Ikar z Krotkovskeho dvora- to help fitting in the standard). Anyway, this gives nowadays if you take CSV born after year 2000: 14% of them does not show Lejdy in their pedigree, which is huge fraction IMHO.