(;SZ[19]AB[sq]AB[rp]AB[qo]AB[qn]AB[qm]AB[ql]AB[rm]AB[rk]AB[sk]AW[rr]AW[rq]AW[qp]AW[pp]AW[oq]AW[ro]AW[pn]AW[pm]AW[pl]AW[qk]AW[qj]AW[rj]C[Black to make a ko for life](;B[so];W[sp]LB[rp:a]LB[rn:b]C[White captures, and the Ko rule prevents Black from recapturing as that creates the same position as before. So Black must find a Ko-threat (like trying to escape at Q5). If White answers the threat (P5) then Black can recapture at a, then ignore any White Ko-threat (assuming one is played) and play at b for sweet, sweet life.RIGHT])(;B[rn];W[sp](;B[sn];W[sl]C[Black is dead. No ko here.];B[so];W[rp]C[Black is dead.])(;B[so];W[sn];B[sm];W[rp];B[so]C[Ko for Death !!]))(;B[sn];W[sp](;B[sl];W[rn]C[Black is dead.])(;B[so];W[rp](;B[sl];W[rn]C[Black is dead.])(;B[sm]C[Black is dead.])(;B[rn];W[sl]C[Black is dead.]))(;B[rn];W[sl];B[so];W[rp]C[Black is dead.]))(;B[sp];W[so];B[sn];W[sr](;B[rn];W[sl]C[Black is dead.])(;B[sl];W[rn]C[Black is dead.]))(;B[sl];W[sp](;B[rn];W[sn])(;B[sn];W[rn])(;B[so];W[sn])))