No touch go

[yebellz]

@yebellz

During the second phase, if Black has the first move, then Black should play at B1 and later A2 to remove that one White stone at A1

This situation is quite peculiar since it depends on who gets to move first in the second phase. If White has the first move, then White should first play at either B1 or A2 in order to ensure that those Black stones remain dead (assuming that is the largest value move on the whole board).

Thus, nearing the end of the first phase, White and Black both want to be the first to pass, in order to have the first move in the second phase (assuming that’s how we decide who gets to play first in the second phase). This motivates both players to skip some needless moves in the first phase, i.e., moves that only facilitate dame filling in the second phase. It might even encourage them to skip some moves that would facilitate the capture / ensure the life of other smaller groups, if this corner was particularly big. Perhaps, some moves analogous to pass fights are possible as well, but that’s a bit tricky to see since the first phase disallows touching.

[ArsenLapin1]

@shinuito

The main issue I would say is remember which stones were played in the first phase!

Of course, this is only an issue irl if playing with Japanese convex stones.

With Chinese flat semi-convex stones, you can play the game stones on one side and the post-game stones upside-down. This is also how professionals sometimes show variations when reviewing a game, playing the game moves on the usual side and the variation moves with upside-down stones.