(;GM[1]FF[4]AP[Drago:4.22.03]SZ[19]CA[UTF-8]AW[rr][qq][rp][sp][pq][oq][nr][mr][lq][lo]AB[nq][np][op][pp][po][qo][ro][so][rq][or][pr]C[Black to play and kill]
(;B[qp]C[This is atari so could be possible.]
(;W[sq]C[If White plays this way it works.];B[qr])
(;W[qr]C[However White can give up just two stones by playing here.];B[sr];W[ps]))
(;B[qr]C[The internal atris is the correct play.]
(;W[sq]C[If White takes Black wins the liberty race.];B[qp];W[rq];B[rs])
(;W[qp]C[This White quickly fails!];B[sq])))
