(;GM[1]FF[4]AP[Drago:4.22.03]SZ[19]CA[UTF-8]AB[rq][rp][qp][pp][op][nq][mp]AW[rr][qq][pq][oq][or][kq]C[Black to play and kill]
(;B[nr]C[This sometimes works, but not with the single white stone to the left.];W[ns];B[lr];W[sr];B[ps]
;W[qs]C[White is alive])
(;B[ns]C[This is the correct play.];W[sr];B[ps];W[os];B[qr]
(;W[rs]
;B[sq]C[White cannot avoid capture])
(;W[nr]C[Pushing through here does not help White];B[mr];W[ms];B[lr];W[rs];B[sq])))
