and
are miai, but White chooses
to get the reverse sente at
. Then Black takes his sente with
-
.
Failure 2: Wrong reverse sente
Failure 3: Premature reverse sente
Next, -
force White to keep pace with
-
. Otherwise Black can make jigo. But
gets tedomari to win by one point.
Finally, the last four plays are all miai. The order of plays does not matter. White wins by 1.
WillerZ found the solution.
I concocted this for Dave, who wondered about "assessing reverse sente dynamically". I also wanted to show the difference between the initial miai, which made no difference in the previous problem.
-- Bill Spight
If takes the wrong miai, Black takes his sente with
-
and then takes the other miai with
. After
the remaining four plays are miai. As with the Final miai diagram, the exact order of play does not matter. The result is jigo.
At first it appears that White can play the reverse sente at instead of
, but
is a mistake.
After we have not reached a miai. Black continues with
. Now
-
is sente because of
and
. After
the last two plays are miai. The result is jigo.
is worth 1.5 points, not 1, so
is sente. But after White replies at
,
is tedomari, and Black gets jigo.
If White starts with the reverse sente at , Black takes the right miai (for him) with
. After
the position has transposed to the Wrong reverse sente diagram.
Note that each player prefers a different play in the initial miai.