(;GM[1]FF[4]AP[Drago:4.22.03]SZ[19]CA[UTF-8]AB[rs][rr][rq][qp][pp][oo][no][mo][ko][lq][lp][kq][jr]AW[qs][qr][qq][pq][op][np][mp][mq][lr][kr][jq][ir][jp]C[Black to play]
(;B[oq]C[This not the correct cut.];W[or];B[mr];W[nq];B[nr];W[oq];B[ls];W[js];B[os];W[ns];B[ms]
;W[ks]C[Black is out of liberties.])
(;B[mr]C[This is the correct cut.];W[or];B[nr];W[oq];B[os]
(;W[ps]C[Making the eye is White's strongest defence.];B[ms];W[js];B[nq]
;W[ns]C[It is a Ko.])
(;W[js]C[Capturing here loses the chance to make the eye.];B[ps];W[ms];B[ns]
;W[ls]C[The white stones 
are alive in Seki,
but so are the black ones of course.])))
