Re: [gnugo-devel] atari_atari problems

[Gunnar Farneback]

Trevor wrote:
> I believe Gunnar said he's working on some bugs in atari_atari.
> Here are some good problems for that:
> 
> trevorb:780
> trevorb:800
> trevorb:880
> 
> As you can see from these, the current atari_atari is broken pretty badly.

I think trevorb:800 is incorrect, or at least not worth regressing
over. White certainly loses the game after playing L4 so considering
that J4 gives more potential for black mistakes, it may be the best
move. However, if black plays correctly, it seems to me like L4 is
bigger than J4. Of course I may have missed some variation and there
is a ko complicating matters, but I don't think the ko is good enough
for white. See sgf below for the main variations in my analysis.

(;GM[1]FF[3]
SZ[13]HA[0]KM[5.5];B[dc];W[jj];B[cf];W[ke];B[dj];W[jc];B[hk];W[kh];
B[jl];W[kk];B[kl];W[gc];B[fj];W[ck];B[cj];W[dk];B[ek];W[bj];B[bi];
W[el];B[fl];W[dm];B[fm];W[bk];B[aj];W[bm];B[fd];W[ll];B[gd]C[!E12];
W[eb];B[db]C[!H10];W[hd];B[fb];W[gb];B[hi];W[fc];B[gf]C[!E10];W[ed];
B[fe]C[E11];W[if];B[hg]C[E11];W[da];B[ec];W[fa];B[cb];W[ak];B[lm];
W[ai];B[bh];W[ml];B[he]C[J9];W[ea];B[id];W[hc];B[ig];W[ie];B[ca];W[jg]
;B[hf];W[ih];B[em];W[dl];B[ii]C[K6|K5];W[hh];B[ji];W[ki];B[jh];W[je];
B[jk]C[J4]
(;W[kj];B[ij];W[ah];B[ag];W[aj];B[bg];W[lk];B[km];W[mm];B[tt];W[tt]
TW[ga][ha][ia][ja][ka][la][ma][fb][hb][ib][jb][kb][lb][mb][ic][kc][lc][mc][id][jd][kd][ld][md][le][me][jf][kf][lf][mf][kg][lg][mg][lh][mh][li][mi][lj][mj][mk][al][bl][cl][am][cm]
TB[aa][ba][ab][bb][ac][bc][cc][ad][bd][cd][dd][ed][ae][be][ce][de][ee][ge][af][bf][df][ef][ff][cg][dg][eg][fg][gg][ch][dh][eh][fh][gh][hh][ih][ci][di][ei][fi][gi][ej][gj][hj][fk][gk][ik][gl][hl][il][gm][hm][im][jm]
C[The game is over.  Final score:
   White = 44 territory + 3 captures + 5.5 komi = 52.5
   Black = 53 territory + 3 captures = 56
Black wins by 3.5.
])

(;W[ij];B[lk]
(;W[kj];B[mk];W[ik];B[hl];W[il];B[im];W[hj];B[gi];W[gj];B[gk];W[lj];
B[mm];W[ah]
C[This might not be sente, but let's assume it is for simplicity.
];
B[ag];W[aj];B[bg];W[kg];B[mj];W[mi];B[tt];W[tt]
TW[ga][ha][ia][ja][ka][la][ma][fb][hb][ib][jb][kb][lb][mb][ic][kc][lc][mc][id][jd][kd][ld][md][le][me][jf][kf][lf][mf][lg][mg][lh][mh][li][al][bl][cl][am][cm]
TB[aa][ba][ab][bb][ac][bc][cc][ad][bd][cd][dd][ed][ae][be][ce][de][ee][ge][af][bf][df][ef][ff][cg][dg][eg][fg][gg][ch][dh][eh][fh][gh][hh][ih][ci][di][ei][fi][ej][fk][gl][ll][ml][gm][hm][jm][km]
C[The game is over.  Final score:
   White = 39 territory + 3 captures + 5.5 komi = 47.5
   Black = 48 territory + 5 captures = 53
Black wins by 5.5.
])

(;W[lj]C[Ko, but does white really have sufficient threats?
])
)

)