Source:
Problem diagram.
What is the value of the endgame play along the bottom?
Go World #1, May-June 1977, pp. 35-37
Solution follows
(or click here to download SGF)
Black plays first.
Black 1 is the best play locally.
The endgame value of this Black 1: how many MORE points does Black have plus how many FEWER points does White have, than if White had played first in this area.
Near the end of the game, after Black and White fill in the points at A,B,C,D, White must play 2, and the position ends with White living with 6 points of territory.
Note that if White neglects to defend at 2, Black ataris on the same point, and with 2 more moves, forms a seki, and White would lose 6 points.
Use this diagram result for reference against the next diagram, in
which White plays first.
White plays first.
The next question to answer is what the position would
most likely look like after White plays first.
White 1 (at White 5) is best. Eventually Black plays 4, and White captures at 5. Black will most likely not play the remaining 1 point gote play, so White's privilege will be the sente play at 7.
So the value of this endgame situation is 11 points because
when Black goes first, Black has 5 more points of territory
along the bottom edge,
and when White goes first, White has 6 more points (3 more
points of territory along the bottom edge, 1 more point of
territory at A, and 2 points from capturing the Black stones).
White variation.
White 1 is slack, because Black 2 simply connects in sente.
After White 3 captures, White is already 1 point worse than
the previous diagram, because White 1 plays inside what
should have been White's own territory.
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