(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2] RU[Japanese]SZ[19]KM[6.50] AW[jl][ll][gm][im][km][ln][mn][nn][ko][no][oo][po][cp][fp][hp][lp][pp][dq][gq][hq][kq][oq][or]AB[jn][kn][io][lo][mo][ro][ip][mp][np][op][rp][iq][mq][pq][qq][nr]PL[W] (;W[ir] (;B[jr]C[CHOICE ] ;W[kr] ;B[hr] ;W[ks] ;B[is] ;W[mr] ;B[lr] (;W[ms]C[RIGHT ]) (;W[nq]C[RIGHT])) (;B[kr]C[CHOICE] (;W[lr] (;B[lq]C[CHOICE ] ;W[kp] ;B[ls] ;W[jr] ;B[mr] ;W[jq]C[RIGHT ]) (;B[kp]C[CHOICE] (;W[jp] ;B[lq] (;W[jr] ;B[jo]C[White did some yose, but Black is alive.]) (;W[mr] ;B[kp]C[RIGHT This is the best defense for Black.])) (;W[lq] (;B[mr]C[Notice that if Black plays elsewhere (K5 or K2), White plays N2 and wins this fight.] ;W[jp] ;B[jo] (;W[jr] ;B[jq]C[White did some yose, but Black is alive.]) (;W[jq] ;B[jr] ;W[js] ;B[kp]C[This is a two-step ko (White can't connect right after that), so it's not the best option.])) (;B[jo] ;W[mr] ;B[os] ;W[ps] ;B[ns] ;W[ms] ;B[jq] ;W[nq] ;B[jr] ;W[ko] ;B[hr] ;W[is])))) (;W[jr] ;B[jq] ;W[lr] ;B[kp] ;W[jp] ;B[jo]C[White did some yose, but Black is alive.])) (;B[kp]C[CHOICE] ;W[jp] (;B[jr]C[CHOICE] (;W[kr] ;B[hr] ;W[ks] ;B[is] ;W[mr] ;B[lr] (;W[ms]C[RIGHT ]) (;W[nq]C[RIGHT])) (;W[jq] ;B[hr] ;W[kr] ;B[is] ;W[mr] ;B[lr] ;W[ms] ;B[ls] ;W[nq] ;B[ns] ;W[mr] ;B[lq] ;W[ks] ;B[kp]C[Two-step ko, not the best option.])) (;B[kr]C[CHOICE] (;W[lr] (;B[jo]C[CHOICE] (;W[jr] ;B[lq]C[White gets some yose, but Black is alive.]) (;W[lq] ;B[mr] (;W[ls] ;B[jq]C[White gets some yose, but Black is alive.]) (;W[jr] ;B[jq]C[White gets some yose, but Black is alive.]) (;W[jq] ;B[jr] ;W[js] ;B[kp]C[This is a two-step ko, so White could do better.])) (;W[mr] (;B[os]C[CHOICE] ;W[kp] ;B[pr] ;W[jr]C[RIGHT]) (;B[kp]C[CHOICE] ;W[lq] ;B[os] ;W[ps] ;B[ns] ;W[ms] ;B[jq] ;W[nq] ;B[jr] ;W[ko] ;B[hr] ;W[is]C[RIGHT]) (;B[jq]C[CHOICE] ;W[lq] ;B[kp] ;W[nq] ;B[ko] ;W[ns]C[RIGHT]))) (;B[lq]C[CHOICE] ;W[mr] ;B[kp]C[RIGHT This is the best defense line for Black.])) (;W[jr] ;B[jq] ;W[lr] ;B[jo]C[White did some yose, but Black is alive.]) (;W[jq] ;B[jr] ;W[lr] (;B[lq] ;W[mr] ;B[kp]C[After this ko (if Black wins), the J2 stone isn't safe. So it's not the best line. ]) (;B[jo] ;W[mr] ;B[kp] ;W[lq] ;B[ms] ;W[ko]) (;B[hr] ;W[mr] ;B[jo] ;W[nq] ;B[kp] ;W[lq] ;B[ko] ;W[ns]))) (;B[jq]C[CHOICE] (;W[jr] ;B[kr] ;W[lr] ;B[lq]C[White did some yose, but Black is alive.]) (;W[kr] ;B[jr] ;W[js]C[RIGHT]))) (;B[lq]C[CHOICE] ;W[kp] ;B[jr] ;W[kr] ;B[hr] (;W[ks] ;B[is] (;W[mr]C[RIGHT]) (;W[lr] ;B[mr] (;W[ms] ;B[ns] (;W[os] ;B[ls] ;W[nq]C[RIGHT]) (;W[nq] ;B[ls] ;W[os]C[RIGHT])) (;W[ns] ;B[ms] ;W[ls] ;B[os] ;W[ps] ;B[pr]C[Ko, not the best.]))) (;W[lr] ;B[mr] (;W[ms] ;B[ns] (;W[os] ;B[ls] ;W[nq]C[RIGHT]) (;W[nq] ;B[ls] ;W[os]C[RIGHT])) (;W[ns] ;B[ms] ;W[ls] ;B[os] ;W[ps] ;B[pr]C[Ko, not the best.])))) (;W[kr] ;B[ir] ;W[mr] ;B[lr] ;W[ms] ;B[lq] ;W[kp] ;B[ls] ;W[ks] ;B[ns]) (;W[lr] ;B[pr]) (;W[mr] ;B[lr] (;W[ir] ;B[kr]) (;W[kr] ;B[ir] ;W[ms] ;B[lq] ;W[kp] ;B[ls] ;W[ks] ;B[ns])))