(;AP[MultiGo:4.4.4]SZ[19]CA[UTF-8]AW[rq][qq][pq][oq][np][er][kq][jq][hr][fq][fr][lp][ep][eo][fn][hn]
[jn][ko][km][mp]AB[rp][qp][pp][op][no][mo][lo][kp][jp][ip][hp][gp][fp][eq][dq][dr]
[cp][cn]TR[gp][fp][hp][ip][jp][kp]C[Black to play to save the marked stones. A ko will do]
(;B[ir]C[This is the correct move]
(;W[iq];B[gr];W[gq];B[hq];W[gs];B[js]
(;W[hs]C[If White plays here Black can capture something];B[lq];W[lr];B[kr];W[mq];B[es];W[is];B[ds];W[jr]
;B[fs]C[White cannot save the four stones])
(;W[lr]C[If White defends here...];B[hs]C[... then black can start a ko]))
(;W[jr]C[This doesn't work for White either];B[hs];W[iq];B[gr];W[is];B[gq];W[gs];B[es])
(;W[is]C[Nor does this work for White];B[jr];W[iq];B[gr];W[gq];B[hq];W[gs];B[lq]))
(;B[gr]C[This first fails.];W[gq];B[ir]
;W[jr]C[White can play here.]))
