[gnugo-devel] clown tengen mane go

[Wolfgang Manner]

i thought a little about that funny game where the "clown"
took -0.5 komi, started at tengen and then played mane go.
the first idea how to fight against it is shown in example 1.
however this works only, if you play against a program which
knows nothing but playing mane go. if you play against a
thinking black opponent, he just doesnt play the "losing move"
and wins easily:

(;GM[1]FF[3]
SZ[9]RU[Japanese]HA[0];B[ee];W[af];B[id];W[bf];B[hd];W[cf];B[gd];W[df]
;B[fd];W[ef];B[ed];W[ff];B[dd];W[gf];B[cd];W[hf];B[bd];W[if];B[ad];
W[ag];B[ic];W[bg];B[hc];W[cg];B[gc];W[dg];B[fc];W[eg];B[ec];W[fg];
B[dc];W[gg];B[cc];W[hg];B[bc];W[ig];B[ac];W[ah];B[ib];W[bh];B[hb];
W[ch];B[gb];W[dh];B[fb];W[eh];B[eb];W[fh];B[db];W[gh];B[cb];W[hh];
B[bb];W[ih];B[ab];W[ai];B[ia];W[bi];B[ha];W[ci];B[ga];W[di];B[fa];
W[ei];B[ea];W[fi];B[da];W[gi];B[ca];W[hi];B[ba];W[ae];B[ie];W[be];
B[he];W[ce];B[ge];W[de]
;B[fe]    ;C[ this is the losing move he just has to capture white ]
;W[aa]
)

you can change this a little. that way "the losing move" comes a bit
earlier, but is still very easy to find:

(;GM[1]FF[3]
SZ[9]RU[Japanese]HA[0];B[ee];W[af];B[id];W[bf];B[hd];W[cf];B[gd];W[df]
;B[fd];W[ef];B[ed];W[ff];B[dd];W[gf];B[cd];W[hf];B[bd];W[if];B[ad];
W[ag];B[ic];W[bg];B[hc];W[cg];B[gc];W[dg];B[fc];W[eg];B[ec];W[fg];
B[dc];W[gg];B[cc];W[hg];B[bc];W[ig];B[ac];W[ah];B[ib];W[bh];B[hb];
W[ch];B[gb];W[dh];B[fb];W[eh];B[eb];W[fh];B[db];W[gh];B[cb];W[hh];
B[bb];W[ih];B[ab];W[ai];B[ia];W[bi];B[ha];W[ci];B[ga];W[di];B[fa];
W[ei];B[ea];W[fi]

;B[da]              ;C[ this is of course the losing move ]

;W[ba];B[hi];W[ae];B[ie];W[be];B[he];W[ce];B[ge];W[de];B[fe];W[ca];
B[gi];W[ii];B[aa];W[ca]

)

you can even construct a hana roku (a rabbity six) and hope that
the opponent doesnt know that:


(;GM[1]FF[3]
SZ[9]RU[Japanese]HA[0];B[ee];W[af];B[id];W[bf];B[hd];W[cf];B[gd];W[df]
;B[fd];W[ef];B[ed];W[ff];B[dd];W[gf];B[cd];W[hf];B[bd];W[if];B[ad];
W[ag];B[ic]

;W[cg];B[gc];W[dg];B[fc];W[eg];B[ec];W[fg];B[dc];W[gg];B[cc];W[hg];
B[bc];W[ig];B[ac];W[dh];B[fb];W[eh];B[eb];W[fh];B[db];W[gh];B[cb];
W[hh];B[bb];W[ih];B[ab];W[ci];B[ga];W[di];B[fa];W[ei];B[ea];W[fi];
B[da];W[gi];B[ca];W[hi];B[ba];W[ii];B[aa];W[hb]

)

one mistake in all these games is that white plays very bad moves
which only work if black imitates them. in the next example i tried
some not so bad white moves. but the black moves are still
ridiculously stupid and i dont think one can expect that black will
play that. instead of the "lousy move" black can play almost anything
and win easily:


(;GM[1]FF[3]
SZ[9]
RU[Japanese]HA[0]
;B[ee]
;W[dd]        ;C[   the white moves are bad, but maybe not that bad ]
;B[ff]
;W[fd]
;B[df]
;W[de]
;B[fe]
;W[ed]
;B[ef]        ;C[  this move is lousy   ]
;W[gg]
;B[cc]        ;C[  at least here black should take the lower corner ]
;W[cg]
;B[gc]
;W[he]
;B[be]
;W[eh]
;B[eb]
;W[cf]
;B[gd]
;W[ge]
;B[ce]        ;C[  now i think black has had it ]
)

assuming that black can play in the beginning nman moves in mane go, what white 
has to do
is to keep this number nman as low as possible and play a game which is 
sufficiently
complicated that black might miss the point where he has to stop the mane go.
certainly one can find a more complicated game to make it more difficult for 
black.

Gunnar had some other ideas:

a. the ladder idea. this sounds very interesting. unfortunately i didnt find a 
good solution.
if you run the two ladders on one diagonal, then the stone at tengen is very 
well placed.

b. superko rule + kos's

in principle
if you play superko
and
if you have a double ko seki
and
if you dont have any ko threats
then
whoever starts the ko will lose everything

i guess you want to avoid that

wolfgang