The first clue about how amateur players interacted with local communities is an account from a poem/writer/composer who lived in this time period - Omachi Keigetsu (大町桂月 1869~1925). He published a book called - 筆 (pen, or to write) in 1908 (明治41年), and there is a paragraph - 囲碁の感 “my thoughts/feelings about Go”. It described how he played handicap games in a Go instructor’s house (a mixture of Go cafe/club/school) near where he lived.
This is what he described - recently, many new buildings opened for business near the village where he lived (somewhere near and just outside of Tokyo). Of all the roadside billboards, many are doctor’s billboard for clinics(醫師), hostels/drinking bars(酒屋), some are tea houses(茶の湯指南の家), flower/internal decoration shops(生花指南の家), and singing/performing theaters (謠曲の家). But he stopped in front of a new Go teaching house billboard. And then he described himself as a player who often played bad or very bad moves(拙手 大拙手), and wasn’t enthusiastic about Go if he couldn’t find others to play with. He was a very casual amateur player and had no hope of reaching shodan (初段 1-dan) or played with people of such strength before.
The owner of the Go teaching house he found was an old man over 50 years old, and said to had the strength of a shodan player. He was welcomed into the establishment. At first, the old man gave him 9 handicaps, and the author won. The next day, they removed 2 handicap stones, and played 7-handicaps games, and then 6-handicaps games, the author still won them. Afterward, he advanced to 5-handicaps games, and he couldn’t win easily. They played 6 to 7 games with 5 handicaps before the old man promoted him to 4 handicaps.
This account is interesting because the player lists in the previous reply I dug up (dated further back around the 1880s to 1890s) had these descriptions :
They basically said that in order to organize (local) Go conventions/competitions, they listed players who had been judged to have the strength of being able to play 2 to 3 handicaps against a player above shodan strength, where some of them marked with circles and triangles were of strength of 3 to 4 handicaps. The implication of these lists, combined with the description from the author Omachi Keigetsu above, is that the compiling of local amateur players lists must have been a bottom up gradual process. Players who were members of the four Great Houses, or the more modern Hoensha, would open local Go teaching houses in places where they lived or travelled to. They would then meet and recruit amateur players in the area as their “customers” as their way of earning their livings by teaching (not that different from many high rank amateurs and pros today). These membership lists would form the basis of the higher up digest lists of strong amateur players in the large area (like a prefecture or city). Ant then, someone finally collected many regional digest lists to compile and boil them down to a giant 5000 people list supposedly covered all of Japan (possibly for the purpose of selling memberships to a Go club covering all Japan, or a mailing list for newspapers/magazines).
How strong players discovered and played with local amateurs using incremental handicaps also corresponds to how dan level players at the time viewed amateurs in their writings. Below is a commentary for a two amateur players game from a book of a collection of real amateur games over the decade, published in 1911 by Nozawa Chikucho (野沢竹朝 1881 ~ 1931), at the time a 4-dan player.
He marked the strength of amateur player such as “準初段格” - a player almost at the level of shodan (probably a stone weaker and doesn’t have a diploma), or at some particular handicaps against certain dan-level strength, like 五段五子 - a player who can play 5 handicaps against a 5-dan player.
The most interesting thing is that these two players above can be found in the giant 5000 player list from 1908.
Where the quasi-shodan player is listed under the “4 kyu” section along an annotation said shodan, and the player of 5 handicaps against 5-dan is listed in the section of “8 kyu”. These two players were from a northern shoreline city (金澤市) in the North-East part of Japan, a relatively isolated city from major Go communities like Tokyo or Osaka.
The kyu ranks in the giant 5000 list are most likely not a good indication of local players’ strength, where they seemed to have their own rank structures and relative strength with each other. They probably also didn’t interact with players from other major hubs often if they were living in remote locations. This wasn’t a single incremental ranking system as we know today (from 9k to 1k and then dan ranks), but an attempt of aggregating various parallel and overlapping ranking systems from different parts of Japan.
A direct evidence of using several rank systems in parallel can be seen in a local Go club list from 1915 (大正四年)
The annotations on the list not only use the Hoensha rank such as 2-kyu shodan (二級初段), but also alleged strength like 二段格 (similar strength to 2-dan, but doesn’t have a diploma), and 12 kyu (十二級) from the old Hoensha rank system (equal to 3-kyu shodan 三級初段 of the new Hoensha system) where their names can be found on the Hoensha member list as far back as 1884 when they still used the old ranking system, corresponding to the first rapid expansion period of Hoensha from 1883 to 1884 to include players in wider areas, that more than doubled their members from 91 to 188 in one year.
I think due to the success of Hoensha in the late 19th century with their newspapers and magazines sold all over Japan as well as mail-Go, the old Hoensha kyu ranking system spread rapidly to various part of local communities in the 1880s to 1890s and became a popular ranking system for many local amateurs who started to play Go around that time. And they would report their local players using the old Hoensha system, where 4 kyu or 5 kyu Hoensha ranks represent the typical strong players, and then used them as measuring standard players for others (or if there were local known dan-level players, they would be the anchors, and most likely judged and organized local leagues)
However, when Hoensha changed back to a mixed dan and multiple kyu-shodan system, not everyone switched with them. Many still stuck with the kyu ranking or already made up their own local ranking system, like the South-West region used a 等 (pronounced “toe”) rank system, quite similar to the old Hoensha kyu rank, but only from 1等 to 9等. The result is that in the early 20th century, there were various ranking systems in different local areas, making the comparison and compiling of a digest list across Japan rather difficult. This is not that different from online Go servers today, where each has its own ranking system. If players don’t play in multiple servers and played with each other, it would be hard to sort everyone out.