Late Edo · the house system
Jowa's blood-vomiting game: three ghost moves under institutional pressure
The legend promises divine inspiration and a defeated prodigy coughing blood. The board is harsher: Jowa did recover and win, but modern KataGo sharply disagrees with the traditional praise of the first ghost move.
Akaboshi Intetsu (Black) vs Honinbo Jowa (White) · 1835.08.13—08.21 · four sessions · White won by resignation · no komi
Before the first move, the office of Meijin Godokoro was already on the board
Edo professional Go was organized through four hereditary houses. Jowa's path to Meijin Godokoro became entangled with rivalry against Inoue Gennan Inseki. The Nihon Ki-in now cautions that some later villainous accounts were literary constructions, while confirming that Gennan's pupil Intetsu was sent to challenge Jowa.
Official course material gives the traditional Tenpo-calendar dates as the seventh month's 19th, 21st, 24th, and 27th; the SGF archive converts them to August 13, 15, 18, and 21. With no komi, Black's first-move advantage also explains much of KataGo's high initial Black win rate.
Where the blood-red legend exceeds the record
Official retellings say Intetsu had a chest illness and collapsed coughing blood after the ordeal. Secondary accounts disagree on when he died, so this essay does not turn an uncertain timeline into eyewitness fact.
The tale that Kannon revealed the three moves in a dream is transmitted folklore, not game documentation. What can be tested is the sequence at White 68, 70, and 80.
Why White 68 became the first ghost move
B11 refuses to submit to Black's rhythm. It creates contact on the left and forces Black to prove that a favorable whole-board position can survive close combat.
KataGo's verdict is provocative: before White 68 it gives Black about 92.3% and +4.9; afterward, about 96.7% and +7.1. On this search, the move is practical resistance, not a numerical reversal.
AI separates two aims: survive cleanly or complicate immediately
The TreeView forks after move 67. The played line is followed by KataGo's continuation; the other branches are candidates from the 10,000-visit search. Since White is to move, lower Black numbers are better for Jowa.
Step through the lines: KataGo first stabilizes the largest area, while Jowa immediately raises the tactical burden.
A classic does not need AI certification
Best by theory, hardest in practice, and bravest in history are different claims. KataGo makes that distinction visible.
The lesson is not to memorize B11, but to see how Jowa repeatedly chose positions that were hardest for an advantaged opponent to settle.