5.6 Territory Rules II
Territory rules II (see Part I) are contrived so as not to count
one-sided neutral points and territory in seki. I naturally favor
territory rules I, which count one-sided neutral points and territory in
seki, but Japanese tradition is against this. The purpose of territory
rules II is to show how the traditional view can be incorporated into a
rigorous set of rules.
One-sided neutral points and territory in seki are both concerned with
seki, so it becomes necessary to define seki. In the final position at
the end of the game, a rigorous definition can be given by defining
stones which cannot be captured even by consecutive play as immortal,
and other stones as non-immortal. Non-immortal stones correspond to the
usual notion of seki.
Stones played on one-sided neutral points and on territory in seki earn
points only if played after the preliminary end of the game, and only
if they remain on the board at the end of the game. The traditional
purpose can therefore be accomplished by subtracting the number of
non-immortal stones played after the end of the game. Note that seki
is not defined at the preliminary end of the game. This allows seki or
one-sided neutral points in the conventional sense at the preliminary
end of the game to undergo change and become immortal by the final end
of the game.
Comparing territory rules I and territory rules II, one is struck by
the awkwardness of the rule added to avoid counting one-sided neutral
points and territory in seki. In addition, if major changes occur after
the preliminary end of the game it may be difficult to determine the
number of non-immortal stones played after the preliminary end. This
rule is both inelegant and impractical. The substantial differences
between territory rules II and area rules II and III are also a major
obstacle to creating an international set of rules. I would like to
propose adopting territory rules I.