(;GM[1]FF[4]CA[UTF-8]AP[CGoban:2]ST[2] RU[Japanese]SZ[4]KM[0.00] PW[Weiß]PB[Schwarz]AW[ba][bb]AB[ac][bc][bd]C[White to play - what's the best he can do?]PL[W] (;W[cc]CR[cc] ;B[cd]CR[cd] (;W[db]CR[db] (;B[dc]CR[dc] (;W[cb]CR[cb] ;B[ab]CR[ab] (;W[aa]CR[aa] ;B[ca]CR[ca] ;W[dd]CR[dd]C[White wins! RIGHT]) (;W[dd]CR[dd] ;B[ca]CR[ca] (;W[dc]CR[dc]C[Next, White captures at D4 and wins by two points (the 2 prisoners), but he can do better!]) (;W[da]CR[da] ;B[dc]CR[dc]C[Next, Black will connect the ko. White wins by 1 point (2 prisoners against 1) then. That is not good enough!]))) (;W[dd]CR[dd] ;B[cb]CR[cb] ;W[ca]CR[ca] ;B[dc]CR[dc] ;W[cb]CR[cb] ;B[ab]CR[ab] ;W[dd]CR[dd]C[White connects the ko and wins by two points (3 prisoners against 1). But he can do better!])) (;B[ab]CR[ab] ;W[ca]CR[ca] ;B[dc]CR[dc] ;W[dd]CR[dd]C[White connects the ko and wins.]) (;B[ca]CR[ca] ;W[ab]CR[ab]C[White lives and wins.])) (;W[cb]CR[cb] ;B[ab]CR[ab] (;W[dc]CR[dc] ;B[da]CR[da] (;W[dd]CR[dd] ;B[db]CR[db] ;W[ca]CR[ca] ;B[db]CR[db] ;W[da]CR[da]C[Seki, White wins by three points (the 3 prisoners). This is not best, White can capture all the black stones!]) (;W[aa]CR[aa] ;B[ca]CR[ca] ;W[db]CR[db] ;B[ca]CR[ca] ;W[da]CR[da]C[Seki, White wins by three points (the 3 prisoners). This is not best, White can capture all the black stones!])) (;W[aa]CR[aa] ;B[da]CR[da] ;W[dc]CR[dc] ;B[db]CR[db] ;W[ca]CR[ca] ;B[db]CR[db] ;W[da]CR[da]C[Seki, White wins by three points (the 3 prisoners). But White can capture all the black stones!]) (;W[dd]CR[dd] ;B[dc]CR[dc] ;W[db]CR[db] ;B[ca]CR[ca] ;W[dd]CR[dd]C[Next, White will connect and then capture at D4. This will be a one point win (two prisoners against 1) - he can do much better!])) (;W[dc]CR[dc] ;B[ab]CR[ab] (;W[cb]CR[cb] ;B[da]CR[da] (;W[aa]CR[aa] ;B[db]CR[db] ;W[ca]CR[ca] ;B[db]CR[db] ;W[da]CR[da]C[Seki, White wins by three poimts (the 3 prisoners). That's not best, White can capture all the black stones!]) (;W[dd]CR[dd] ;B[db]CR[db] ;W[ca]CR[ca] ;B[db]CR[db] ;W[da]CR[da]C[Seki, White wins by three points (the 3 prisoners) That's not best, White can capture all the black stones!])) (;W[da]CR[da] ;B[cb]CR[cb] (;W[ca]CR[ca] ;B[aa]CR[aa] ;W[db]CR[db]C[Seki, White wins by one point (the prisoner). He can do much better!]) (;W[db]CR[db] ;B[aa]CR[aa] ;W[ca]CR[ca]C[Seki, White wins by one point (the prisoner). He can do much better!])) (;W[db]CR[db] ;B[ca]CR[ca] (;W[cb]CR[cb] ;B[aa]CR[aa] ;W[da]CR[da]C[Seki, White wins by one point (the prisoner). He can do much better!]) (;W[da]CR[da] ;B[aa]CR[aa] ;W[cb]CR[cb]C[Seki, White wins by one point (the prisoner). He can do much better!])) (;W[ca]CR[ca] ;B[db]CR[db] (;W[cb]CR[cb] ;B[aa]CR[aa] ;W[da]CR[da]C[Seki, White wins by one point (the prisoner). He can do much better!]) (;W[da]CR[da] ;B[aa]CR[aa] ;W[cb]CR[cb]C[Seki, White wins by one point (the prisoner). He can do much better!])))) (;W[cb]CR[cb] ;B[cc]CR[cc] (;W[dc]CR[dc] ;B[ab]CR[ab] ;W[db]CR[db] ;B[ca]CR[ca]C[Now, please capture :)] (;W[dd]CR[dd]C[NOTTHIS]) (;W[aa]CR[aa]C[NOTTHIS]) (;W[da]CR[da]C[Seki, White wins by one point (the prisoner).])) (;W[db]CR[db] ;B[dc]CR[dc] ;W[ab]CR[ab]C[Jigo!])))