One of the questions that we think HaMapah can help answer is the dynamics of succession. When a posek dies or is otherwise incapacitated, who picks up the slack? Does it diffuse among multiple poskim or is there an heir apparent?
It is safe to say that we will see different patterns emerge as the project continues, but today we are going to look at a fairly elegant series of successions in Hungary during the latter half of the nineteenth century. Hatam Sofer, the subject of several posts thus far, was, by the time he passed away in late 1839, the leading posek in Hungary. Three poskim who served the same territory after his passing were Rabbi Yehudah (or Mahari) Aszod (1794-1866), author of Shu”t Yehudah Ya’aleh; Rabbi Avraham Shmuel Binyamin Sofer (1815-1871), the son of Hatam Sofer and author of Shu”t Ketav Sofer; and Rabbi Moshe Schick, author of Shu”t Maharam Schick (1807-1879).
Let’s look at a map of the responsa of these four poskim (including Hatam Sofer). As always, opening separately and using the selectors is recommended (but today more so than usual).
The similarity of each posek’s map to the others is remarkable, and we will come back to this.
Now let’s look at the dates of the responsa. The data contained in Mahari Aszod’s responsa is somewhat sparse, but we have dates for a good proportion of responsa by Ketav Sofer and Maharam Schick.
It should be noted that nothing is proven, and that the picture that we see is conjectural, and our roles but the pattern seems pretty clear: There is a “passing of the mantle” from Mahari Aszod to Ketav Sofer to Maharam Schick. Ketav Sofer, it seems, does not become the leading posek in Hungary until Mahari Aszod’s death (and subsequent portrait!) in 1866. When Ketav Sofer’s health began to decline, Maharam Schick took his place as the leading Hungarian posek. It is actually quite amazing to see how many of Maharam Schick’s responsa were penned in the last decade of his life.
Returning to the similarity of the maps, Moshe has developed tools that will quantify the geographical similarity of the spheres of authority of any two poskim. This will be very useful for tracing things like succession, demarcating cultural boundaries, and demonstrating reach. We will devote a separate post to these. For now, it suffices to say that the geographic similarity of these four poskim is high enough that our categorization of them as “Hungarian poskim” holds water.
 Simply put, we create a vector of the number of responsa to each city for each posek, and then take the cosine of the angle between them. Alternatively, we’ll take that vector and map to a binary vector, again, with each city its own dimension, and then take the angle between those two. We generally use an averaged version of the two methods.