(;GM[1]FF[4]CA[UTF-8]AP[CGoban:2]ST[2] RU[Japanese]SZ[4]KM[0.00] PW[Weiß]PB[Schwarz]AW[da][cb][db][dc]AB[ab][ac][cc][ad]C[Black to play - what's the best he can do?] (;B[bb]CR[bb] (;W[cd]CR[cd] (;B[bd]CR[bd] ;W[bc]CR[bc] (;B[ca]CR[ca] ;W[ba]CR[ba] ;B[cc]CR[cc]C[and Black wins. RIGHT]) (;B[ba]CR[ba] ;W[cc]CR[cc]C[White wins by one point!])) (;B[bc]CR[bc] ;W[ba]CR[ba]C[Seki & jigo]) (;B[ba]CR[ba] ;W[bc]CR[bc] ;B[bd]CR[bd] ;W[cc]CR[cc]C[Seki, White wins by one point (the prisoner)])) (;W[ba]CR[ba] ;B[cd]CR[cd]C[Black wins (one eye beats no eye)])) (;B[bc]CR[bc] ;W[bb]CR[bb] (;B[ba]CR[ba] ;W[cd]CR[cd]C[Seki & jigo]) (;B[cd]CR[cd] ;W[ba]CR[ba]C[Seki & jigo])) (;B[cd]CR[cd] ;W[bb]CR[bb] (;B[ba]CR[ba] ;W[bc]CR[bc] ;B[bd]CR[bd]C[Seki & Jigo]) (;B[bc]CR[bc] ;W[ba]CR[ba]C[Seki & Jigo])) (;B[ba]CR[ba] ;W[bc]CR[bc] ;B[cd]CR[cd] ;W[bb]CR[bb] ;B[bd]CR[bd]C[Seki & jigo]))