The Meijin/shogidokoro
The three shogi houses and their heads were officially recognised. The shogi players under them would receive a small stipend, indirectly from the shogunate via their iemoto; in exchange, they would have to perform their duties, staying in the capital Edo for long periods to practice their craft, and be overseen by the shogunate.
Among the houses, however, there was of course the natural question of who the strongest among them was. The answer to that was the position of Meijin. A single player, judged to be the strongest of the time, would be appointed to this position by agreement of all three houses. By nature of the choice, this was a virtually unambiguous recognition of this person’s skill and seniority. This was a lifetime position, with just a single exception in the Edo period (Itou Soukan I, who voluntarily retired in 1691.)
The Meijin was also sometimes called the shogidokoro (将棋所), just as the go Meijin was called the godokoro. There are a number of widely-repeated claims of other meanings or origins of the terms shogidokoro and godokoro, such as them evolving from an appellation kidokoro given to the eight players selected in 1612. This claim even features in some encyclopedias, but there is no historical evidence of these terms being used back then. The evidence points towards shogidokoro being a synonym of “Meijin” used by the shogi houses themselves.
One point to note is that the Meijin was not an officially recognised position by the shogunate; it was a position decided by the shogi houses among themselves. Nevertheless, the Meijin would function as a kind of liaison between the shogunate and the shogi houses, and wield considerable authority within the shogi world.
Dan and kyu ranks
The iemoto did not only have the authority to decide the next Meijin among themselves, but also to rank other players and evaluate them for their suitability in leadership roles.
The iemoto alone (supervised by the shogunate jisha-bugyou, temple and shrine magistrates) had the authority to issue ranks to players according to their strength. This was the origin of a standardised dan and kyu rank system nationwide, backed by the authority of the Meijin, the houses, and the shogunate.
Players started with a kyu rank, rising to 1-kyu as they became stronger. After 1-kyu, they could become 1-dan, then get further promoted through the dan ranks all the way up to 7-dan, which was the highest rank an outsider could achieve. 8-dan was awarded only to potential candidates for the next Meijin, and could be held only by members of one of the main schools. 9-dan was a rank held only by the Meijin. Due to the Meijin being the strongest player in principle and in practice, the ranking system reflected not simply seniority, but true playing strength.
For such an objectively skill-based game as shogi, there was no room for weakness. The Meijin had to be seen as the strongest player to maintain their authority. Each of the houses’ shogi players would also be ranked among themselves for ability – and against outside challengers, of whom there were no shortage. Strong players and talented children would seek training under the masters – or be sought by the houses, for the houses too had to actively maintain their position as the strongest.
The institution of the iemoto system granted financial stability and recognition to the three houses, enabling their work as “professionals”. On the other hand, everybody else was an “amateur”, necessarily having another way to make a living, although they may have been very strong players themselves.
There were the houses’ external students and disciples, who also possessing ability, talent, and quite possibly ambition, but would often be unable to make a living off shogi alone.
There was the Hon’inbo go house, famous for go but like their founder Sansa, also strong at shogi.
There were unaffiliated players (在野派棋客, perplexingly mistranslated as “Arino” or “Zaino” players in some English sources), not actively studying under the houses, but nonetheless formidable opponents through talent, experience, or both. A small subset of these were the “shinkenshi” (真剣士), who would make a living as shogi hustlers – a risky occupation, as gambling was a serious offence under the shogunate.
These independent powerhouses were not pleased with the new iemoto status of the shogi houses, and would frequently send challenges to the second Meijin Oohashi Souko II. On behalf of the older Souko, head of the Itou house Itou Soukan (伊藤宗看) would take them on, defeating Matusmoto Shouson (松本紹尊) in 1637, Hagino Maho (萩野真甫) in 1641-1649 (lance handicap, 40-30 to Soukan), and many other challengers.