(;GM[1]FF[4]CA[UTF-8]AP[CGoban:2]ST[2]
RU[Japanese]SZ[4]KM[0.00]
PW[Weiß]PB[Schwarz]AW[ca][ab][bb][cb]AB[da][ac][bc][cc][dd]C[Black to play - what's the best he can do?]
(;B[db]CR[db]
(;W[bd]CR[bd]C[W D2 is a variation]
(;B[dc]CR[dc]
;W[cd]CR[cd]C[White wins!])
(;B[ba]CR[ba]
;W[dc]CR[dc]
;B[db]CR[db]
;W[aa]CR[aa]
;B[dc]CR[dc]
;W[cd]CR[cd]
;B[ad]CR[ad]
;W[bd]CR[bd]
;B[cd]CR[cd]C[Black wins by one point - 4 prisoners against 3. RIGHT])
(;B[cd]CR[cd]
;W[dc]CR[dc]
;B[db]CR[db]
;W[da]CR[da]
;B[ba]CR[ba]
;W[dc]CR[dc]C[White wins!])
(;B[ad]CR[ad]
;W[dc]CR[dc]
;B[db]CR[db]
;W[da]CR[da]
;B[ba]CR[ba]
;W[dc]CR[dc]C[White wins!])
(;B[aa]CR[aa]
;W[dc]CR[dc]
;B[db]CR[db]
;W[ba]CR[ba]
;B[dc]CR[dc]
;W[cd]CR[cd]
;B[ad]CR[ad]
;W[cd]CR[cd]
;B[bd]CR[bd]C[Black wins by one point - 4 prisoners against 3. RIGHT]))
(;W[dc]CR[dc]
;B[db]CR[db]
;W[bd]CR[bd]
(;B[ba]CR[ba]
;W[aa]CR[aa]
;B[dc]CR[dc]
;W[cd]CR[cd]
;B[ad]CR[ad]
;W[bd]CR[bd]
;B[cd]CR[cd]C[Black wins by one point - 4 prisoners against 3. RIGHT])
(;B[dc]CR[dc]
;W[ad]CR[ad]
;B[cd]CR[cd]C[Black wins by one point - 3 prisoners against 2. RIGHT])))
(;B[dc]CR[dc]
;W[bd]CR[bd]
;B[db]CR[db]
;W[ad]CR[ad]C[Black loses the capturing race])
(;B[bd]CR[bd]
;W[db]CR[db]
;B[dc]CR[dc]C[White wins by two points!]))