(;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])))