Mirror go - Game 1
White: Fujisawa Hosai 9-dan
Black: Yamabe Toshiro 9-dan
Komi: 4.5
This game was one of the semi-finals of the challengers' knockout in the 20th Nihon Ki-in Championship, one of the more important events in 1972. This commentary is not a translation but is based mainly on Yamabe's own comments.
It is worth noting that by this stage there wasn't too much controversy about mirror go - most of the hullabaloo was after the war, when oddly enough it was less onerous for Black than it was in 1972. The early protesters did not have to give komi, though it was already normal even before the seventies.
1-10
As a rule of thumb, GoGoD does not count a game as mirror go unless it continues after move 20, but with Fujisawa's history, Yamabe could be fairly certain what was coming next once he saw White 10, or even earlier perhaps.
Variation Diagram 1 (1-15)
Yamabe said he considered Black 1 in Diagram 1 in place of Black 9. If you know your moves are going to be copied you can be slightly outlandish. In this case he felt that Black 15. occupying the centre point very early was good, as it is a key point for attack and defence. But, of course, White is not forced to copy and with one rash move Black can be caught with his trousers down. Yamabe decided that straightforward moves were best.
It might seem as if the fuss about mirror go would centre on White getting a huge advantage in time, but that never really applied in Fujisawa's case as he was a notoriously slow player even in his mirror games, and in any case Yamabe was a very fast player.
Yamabe claimed that at the time of this game he had lost more than a dozen games in a row against Fujisawa and that he was in danger of becoming known as a "duck" - a sucker or an easy target - with the need to take a handicap. This seems to be conventional, if unusually exaggerated, modesty by Yamabe, who once styled himself a "third-grade 9-dan". Apart from the fact that the record does not seem to bear him out, if he really had lost so many games he would have been quacking already.
11-27
Black 27 was the first key point. Yamabe considered Black 1 in the diagram below. It was questionable whether White would indeed agree that move 12 was the point at which to end the mimicry, but even assuming that, the postulated result up to White 20 gives Black an area within the Xs of 21 points against 16 points on the White side. That may have been sufficient to win with 4.5 komi as in this game, but not with the 5.5 komi that was becoming more general then. Yamabe had looked at various similar ways of forcing an advantage in centre territory, but he concluded that none of them was sufficient to make Black confident of winning.
Variation Diagram 2 (1-20)