(;SZ[13]AW[ea]AW[db]AW[fb]AW[dc]AW[ec]AW[gc]AW[hc]AW[dd]AW[be]AW[ce]AW[cg]AW[dh]AB[cb]AB[cc]AB[fc]AB[cd]AB[ed]AB[fd]AB[de]AB[he]AB[ef]AB[eg]C[Black to play. Can Black rescue the three stones in the corner?]GM[1]FF[4]CA[UTF-8]AP[CGoban:2]ST[2]RU[Japanese]KM[0.00]TM[]PW[White]PB[Black]PL[B]
(;B[da];W[ca];B[ba];W[da]
(;B[ab];W[ad]
(;B[ac];W[bc]
(;B[bd];W[bb])
(;B[bb];W[bd]))
(;B[bc];W[ac])
(;B[bd];W[ac]))
(;B[bd];W[bb];B[ab];W[aa];B[bc];W[ba])
(;B[ac])
(;B[gb];W[hb]
(;B[ga];W[ha];B[ab];W[ad])
(;B[fa];W[ga]))
(;B[bc];W[ac]
(;B[ab];W[ad])
(;B[ad];W[ab]
(;B[ae];W[bd])
(;B[bb];W[bd];B[aa];W[ae])
(;B[bd];W[ae]))))
(;B[ba];W[ab];B[da]C[ B13 is the vital point. Black gets a ko.RIGHT])
(;B[bd];W[da]C[Black has no space to get two eyes.])
(;B[ca]
(;W[da]C[CHOICE];B[gb]
(;W[ac]C[CHOICE]
(;B[ga]C[Black cannot win the capture race.];W[hb];B[fa];W[ha])
(;B[hb]C[Black cannot win the capture race.];W[bd]
(;B[ga];W[ib]
(;B[fa];W[ha])
(;B[ia];W[ja]
(;B[fa];W[ha])
(;B[jb];W[bb]
(;B[fa];W[ha])
(;B[ic];W[ba];B[fa];W[bc]))))
(;B[ib];W[bc]
(;B[bb];W[ab];B[fa]
(;W[ba])
(;W[ga];B[ha];W[ba]))
(;B[ga];W[bb];B[fa];W[ba]))))
(;W[hb]C[CHOICE];B[ga];W[ha]))
(;W[gb]C[CHOICE];B[da];W[eb])
(;W[ac];B[da];W[eb];B[gb])
(;W[ab];B[da];W[eb];B[gb]))
(;B[gb];W[hb];B[ga];W[ha];B[da];W[ca];B[ba];W[da];B[ab];W[ad]))
