(;FF[4]SZ[9]C[Black to play the only killing move.
I constructed this problem myself. It has a fairly simple, but a bit counter intuitive solution, which is probably why it has such a high rank.]
AB[ba][eb][gb][gc][ad][dd][ed][fd][ae][be][ce]
AW[bb][fb][bc][dc][ec][fc][bd]
(;B[db];W[fa];B[cc];W[cb];B[cd];W[da];B[ab];W[ea];B[ac]C[RIGHT])
(;B[fa];W[db];B[cc];W[da];B[ab];W[cb];B[ac];W[cd];B[ga];W[ea])
(;B[ea];W[fa];B[cc];W[cb];B[ga];W[cd])
(;B[ab];W[ac];B[da];W[cb];B[fa];W[ca])
(;B[da];W[cb];B[fa];W[ca])
(;B[ac];W[ab];B[fa];W[db];B[ea];W[ca])
(;B[cd];W[ea];B[ac];W[db];B[ab];W[ca];B[cc];W[cb])
(;B[cc];W[db];B[cb];W[cd];B[da];W[ca];B[cb];W[ea]C[White does not need to respond to this.]))