The shape in the lower right corner occurred in a really close (.5 points) game I was reviewing. It seemed common and interesting enough to warrant a problem of its own, so here you go. As always, please add a comment if you spot a mistake or an interesting path that is not included.
(;SZ[7]AB[ab]AB[ba]AB[ca]AB[cb]AB[db]AB[eb]AW[ac]AW[bc]AW[bb]AW[bd]AW[cc]AW[dc]AW[dd]AW[ce]AW[be]AW[bf]AB[cf]AW[df]AW[ef]AW[ff]AB[de]AB[ee]AB[fe]AB[gf]AB[ed]AB[ec]C[No komi, no prisoners, black to play and win.]AW[ae]AB[ea]AP[goproblems]
(;B[fg];W[cg]
(;B[eg]
(;W[dg]
(;B[aa];W[gg]C[];B[fg];W[eg]
(;B[ge];W[gg];B[bg];W[cf];B[fg]C[Black wins by one point!RIGHT])
(;B[gg];W[ge]))
(;B[ge];W[gg];B[fg];W[aa]C[Jigo.]))
(;W[aa]C[This does not help white.];B[ge];W[ab];B[gg];W[dg]C[Black wins by one point.RIGHT]))
(;B[aa];W[eg];B[ge];W[gg]C[Jigo.])
(;B[ge];W[eg]
(;B[aa];W[gg]C[Jigo.])
(;B[gg];W[aa]C[Jigo.]))
(;B[gg];W[eg];B[ge];W[aa]C[Jigo.]))
(;B[aa];W[fg]C[White wins.])
(;B[cg];W[fg]C[White wins.])
(;B[gg];W[fg]C[White wins.])
(;B[dg];W[fg]C[White wins.])
(;B[eg];W[fg]C[White wins.])
(;B[ge];W[fg]C[White wins.]))
