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Ikeda rules
Posted: Sun Sep 06, 2015 8:42 am
by vier
Searching info about Ikeda rules, I encountered the SGF of a game
PB[Ikeda Toshio]
PW[Go Seigen]
KM[-4]
RE[W+11.5]
HA[3]
RU[Ikeda's Area Rules III]
GC[After the first pass, end on two successive passes.
In even games, if first pass is by W, subtract 0.5 point from B and give to W.
For 3 handicap stones, subtract 1.5 points and for last move add 0.5,
and add 2 points for 4 points komi (W thus needs at least 181.5 not to lose).]
...
Is it really possible under Ikeda's Area Rules III to have a nonintegral score while komi is integral?
The SGF says
SO[Ikeda's book]
but I think the translation of that book found on the net does not contain this game.
Re: Ikeda rules
Posted: Sun Sep 06, 2015 9:18 am
by RobertJasiek
http://home.snafu.de/jasiek/rules.htmlRead under Ikeda Style Rules and commentaries on the related rulesets incl. (Simplified) World Mind Sports Games (2008) Rules.
Re: Ikeda rules
Posted: Sun Sep 06, 2015 10:40 am
by vier
Is it really possible under Ikeda's Area Rules III to have a nonintegral score while komi is integral?
Is this a complicated way of saying 'No'?
Re: Ikeda rules
Posted: Sun Sep 06, 2015 11:13 am
by RobertJasiek
It is an easy way to provide you some requested information about Ikeda Rules - and the correct answer No:)
Re: Ikeda rules
Posted: Sun Sep 06, 2015 12:02 pm
by vier
RobertJasiek wrote:It is an easy way to provide you some requested information about Ikeda Rules - and the correct answer: No
Thanks! Does anyone know the correct data for this game?
Re: Ikeda rules
Posted: Sun Sep 06, 2015 8:50 pm
by Bill Spight
vier wrote:RobertJasiek wrote:It is an easy way to provide you some requested information about Ikeda Rules - and the correct answer: No
Thanks! Does anyone know the correct data for this game?
Why don't you post the game record? Remove comments if that's a problem.

Or provide the URL.

Re: Ikeda rules
Posted: Tue Sep 08, 2015 6:44 am
by vier
Bill Spight wrote:Why don't you post the game record?
I know about several versions, all incomplete. Logan (Go_Seigen_1d.pdf, p. 938) does not give the result.
The nonintegral RE looks like a mistake. Maybe the GC is mistaken as well?
If this is from a book about rules and counting I would not expect a semi-finished game.
(;
PB[Ikeda Toshio]
PW[Go Seigen]
KM[-4]
RE[W+11.5]
DT[Published 1992]
RU[Ikeda's Area Rules III]
GC[After the first pass, end on two successive passes.
In even games, if first pass is by W, subtract 0.5 point from B and give to W.
For 3 handicap stones, subtract 1.5 points and for last move add 0.5,
and add 2 points for 4 points komi (W thus needs at least 181.5 not to lose).]
SO[Ikeda's book on rules]
HA[3]
AB[dp][pd][pp]
;W[cd];B[ec];W[hc];B[cg];W[ed];B[dd];W[de];B[dc];W[be];B[fd] ...)
http://www.lifein19x19.com/forum/download/file.php?id=6392
Re: Ikeda rules
Posted: Tue Sep 08, 2015 8:27 am
by Bill Spight
vier wrote:Bill Spight wrote:Why don't you post the game record?
I know about several versions, all incomplete. Logan (Go_Seigen_1d.pdf, p. 938) does not give the result.
The nonintegral RE looks like a mistake. Maybe the GC is mistaken as well?
If this is from a book about rules and counting I would not expect a semi-finished game.
(;
PB[Ikeda Toshio]
PW[Go Seigen]
KM[-4]
RE[W+11.5]
DT[Published 1992]
RU[Ikeda's Area Rules III]
GC[After the first pass, end on two successive passes.
In even games, if first pass is by W, subtract 0.5 point from B and give to W.
For 3 handicap stones, subtract 1.5 points and for last move add 0.5,
and add 2 points for 4 points komi (W thus needs at least 181.5 not to lose).]
SO[Ikeda's book on rules]
HA[3]
AB[dp][pd][pp]
;W[cd];B[ec];W[hc];B[cg];W[ed];B[dd];W[de];B[dc];W[be];B[fd] ...)
Thanks for posting the SGF file.

I found the same game record in GoGOD, BTW.
There is a clue to the final fractional result in the Game Comment.
add 2 points for 4 points komi (W thus needs at least 181.5 not to lose).
The comment neglects to add that for 4 points komi Black would subtract 2 points, while White would add 2 points. Why not just add 4 points to White's score? The answer, I think, is that the game was scored in the Chinese fashion instead of the Japanese fashion. If White needed 181.5 points for jigo, but had 193 points, then that would explain the 11.5 point win.

Re: Ikeda rules
Posted: Tue Sep 08, 2015 9:17 am
by vier
Bill Spight wrote:The answer, I think, is that the game was scored in the Chinese fashion instead of the Japanese fashion.
Yes, that makes sense. And apparently Chinese area scoring does not count handicap stones.
(At least Ikeda Area rules III do not:
http://gobase.org/studying/rules/ikeda/?sec=e5020000.)
Still the question remains: can somebody find the original source?