Natural Situational Superko Rule
Natural situational superko rule: A player may not use a board play to recreate a position if he has used one to create it.
This rule is used in some rules. (Needs expanding) But is also interesting from a go theoretical perspective.
The difference between the Natural situational superko rule and the situational superko rule is subtle, and is unlikely to affect any realistically played game.
The difference is that under situational superko (non-natural), you cannot make a move that creates a position that was on the board previously after you passed. With natural, you are allowed to make such a move.
Example on 5x5 board:
last point
strange move, white gives black a stone needlessly
takes ko
pass (no legal moves)
pass (for some weird reason)
Now White cannot capture in the corner under either situational rule, because this position was created with a board play (), not with a pass.
RobertJasiek: If you want a real difference, consider moonshine life. If you want great differences only in move-sequences but not the outcome, consider double-ko-seki.
see also
http://home.snafu.de/jasiek/superko.html
This page is copied from
http://senseis.xmp.net/?posting=5391#P5391