(;SZ[4]AW[ba]AW[da]AW[bb]AW[cd]AW[dd]AB[ab]AB[ac]AB[bd]C[Black to play. What is the best he can do?]GM[1]FF[4]CA[UTF-8]AP[CGoban:2]ST[2]RU[Japanese]KM[0.00]PW[WeiÃx]PB[Schwarz] (;B[bc] (;W[cb]C[CHOICE];B[cc];W[dc];B[db];W[dc]C[Seki. Black wins by two points, 3 prisoners against 1.RIGHT]) (;W[db];B[cc];W[dc];B[cb]C[White is lostRIGHT]) (;W[dc];B[cb]C[White is deadRIGHT]) (;W[cc];B[cb]C[White is deadRIGHT])) (;B[cc] (;W[bc]C[CHOICE] (;B[dc];W[cd];B[dd];W[cb]C[White wins.]) (;B[cb];W[ad]C[] (;B[dc];W[bd]) (;B[ca];W[aa]) (;B[db];W[ca];B[bd];W[dc]))) (;W[cb]C[This gives Black a chance to reach the solution];B[bc];W[dc];B[db];W[dc]C[Black wins by two points, but White C3 was clearly a mistake.])))