(;GM[1]FF[4]AP[Drago:4.22.03]SZ[19]CA[UTF-8]AB[rs][rr][rq][rp][qo][po][oo][np][nq][mp][lp][kp][kq][jr][js]AW[ks][lr][lq][mq][nr][or][op][pp][qp][qr][qs]C[Black to play]
(;B[kr]C[Black should not start here as White can make Ko.]
(;W[ms];B[ls])
(;W[ls]C[If White connects here the stones just die.];B[ns]
(;W[os];B[ms];W[mr];B[pr];W[pq];B[qq];W[ps];B[oq])
(;W[mr];B[pr])
(;W[pr];B[mr])))
(;B[ms]C[This is the vital point.];W[mr]
(;B[kr]C[Now Black can play here.];W[ls]
;B[ns]C[This is the key to stopping a second eye.]
(;W[os]
;B[pr]C[Then this stops the eye here.])
(;W[qq]C[If White tries to make this eye...];B[oq];W[pq]
;B[ps]C[... then White is out of liberties.])
(;W[pq];B[qq];W[oq]
;B[ps]C[Again White runs out of liberties.]))
(;B[ns]C[This may look like an eye steeling move but White can make seki.];W[pr];B[os];W[kr])
(;B[pr]C[Trying to take this eye away too early fails.];W[pq];B[qq];W[ps];B[oq]
;W[ns]C[White is alive.])))
