Shusaku-style Numbers for other Players

Most deshi know what a Shusaku number is: a maximum amount of games which connects a player to Shusaku through a chain of common opponents. A lower Shusaku number takes precedence over a higher Shusaku number. This article aims to extend the idea from Shusaku to other famous players. These numbers are just maximums and may not always be the lowest possible.

In particular, it aims to use Shusai as an anchor as he is already a common part of Shusaku numbers. The paths should be chronological. The date in brackets is the first chronologically consistent recorded game played between that player and the player one step chronologically later. If you can't find the games then it's because they're listed under another name, not necessarily the one they were actually using at the time.

Honinbo Shuei

Path: Shusai -- Shuei (1891)

Number: Shusai + 1

Good alternative path players: Iwasa Kei, Karigane Junichi, Suzuki Tamejiro.

Honinbo Shuho

Path: Shusai -- Shuei (1891) -- Shuho (1866)

Number: Shusai + 2

Honinbo Shusaku

See Shusaku number.

Path: Shusai -- Iwasaki Kenzo (1889) -- Shusaku (1859)

Number: Shusai + 2

Honinbo Shuwa

Path 1: Shusai -- Shuei (1891) -- Shuho (1866) -- Shuwa (1850)

Path 2: Shusai -- Iwasaki Kenzo (1889) -- Shusaku (1859) -- Shuwa (1842)

Number: Shusai + 3

Honinbo Jowa

Path: Shusai -- Iwasaki Kenzo (1889) -- Shusaku (1859) -- Jowa (1847)

Number: Shusai + 3

Honinbo Genjo

Path: Shusai -- Iwasaki Kenzo (1889) -- Shusaku (1859) -- Jowa (1847) -- Genjo (1814)

Number: Shusai + 4

Honinbo Dosaku

Path: Shusai -- Iwasaki Kenzo (1889) -- Shusaku (1859) -- Jowa (1847) -- Genjo (1814) -- Yasui Senchi (1798) -- Satsugen (1784) -- Hakugen (1752) -- Inoue Shunseki Inseki? (1747) -- Shuhaku (1738) -- ???

I wasn't able to trace this path all the way due to two problems: sparsity of kifu and not being sure if two games listed under the traditional name of a head of a house belonged to the same player.