(;GM[1]FF[4]CA[UTF-8]AP[CGoban:2]ST[2] RU[Japanese]SZ[4]KM[0.00] PW[Weiß]PB[Schwarz]AW[aa][cb][ac][bc]AB[ca][da][cc][dc][ad]C[Black to move - what's the best he can do?]PL[B] (;B[bb]CR[bb] (;W[ab]CR[ab] (;B[cd]CR[cd] ;W[ba]CR[ba] ;B[db]CR[db] ;W[bd]CR[bd] ;B[bb]CR[bb]C[...and Black wins! RIGHT]) (;B[db]CR[db] ;W[cd]CR[cd] (;B[dd]CR[dd] ;W[bd]CR[bd]C[Seki & Jigo (1 prisoner each)!]) (;B[ba]CR[ba] ;W[bd]CR[bd]C[Seki & Jigo (1 prisoner each)!])) (;B[bd]CR[bd] ;W[cd]CR[cd] (;B[bd]CR[bd] ;W[ba]CR[ba]C[White wins]) (;B[db]CR[db] ;W[ba]CR[ba] ;B[bd]CR[bd] ;W[cb]CR[cb]C[White wins]))) (;W[cd]CR[cd] (;B[db]CR[db] ;W[ab]CR[ab] (;B[ba]CR[ba] ;W[bd]CR[bd]C[Seki & Jigo (1 prisoner each) - B D3 was a mistake!]) (;B[dd]CR[dd] ;W[bd]CR[bd]C[Seki & Jigo (1 prisoner each) - B D3 was a mistake!])) (;B[ba]CR[ba]C[Black wins!])) (;W[bd]CR[bd] ;B[cd]CR[cd] ;W[ab]CR[ab] ;B[db]CR[db]C[...and Black wins.])) (;B[cd]CR[cd] ;W[bb]CR[bb] ;B[db]CR[db] ;W[bd]CR[bd]C[White wins!]))