(;GM[1]FF[4]AP[Drago:4.22.03]SZ[19]CA[UTF-8]AB[rs][rr][rq][qq][pq][ps][op][oo][no][mo][lo][lp][kq][kr][ks]AW[lq][lr][ls][mp][np][oq][or][pr][qr][qs]C[Black to play and kill.]
(;B[nq]C[Playing this atari fails to kill all the white stones.];W[nr];B[mq]
;W[mr]C[White is alive at the cost of two stones.])
(;B[mq]C[This is no different.];W[mr];B[nq];W[nr])
(;B[mr]C[This fails too.];W[mq];B[nr];W[ns])
(;B[nr]C[This is the correct play.];W[nq]C[This is white's strongest defence.];B[ms]C[However this threatens a snap-back.];W[mq];B[os]
;W[ns]C[After this black recaptures (7 at 5) and creates a killing shape.];B[os]))
