(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]
RU[Japanese]SZ[19]KM[0.00]
PW[White]PB[Black to play and kill]AW[mo][no][lp][op][lq][oq][nr]AB[pl][nm][ln][pn][ko][kp][np][pp][hq][kq][qq][qr]
(;B[lr]C[Sometimes the hane reduces the eye space but this makes living easy for White.]
;W[mr]
;B[kr]
;W[pr]
;B[os]
;W[ps]C[Two eyes.])
(;B[kr]C[Sometimes the drop like this works.]
;W[pr]
;B[os]
;W[ps]
;B[ns]
;W[mr]
;B[ms]
;W[ls]
;B[lr]
;W[or]
;B[ms]
;W[ns]C[Two eyes])
(;B[os]C[Black could try from this side.]
;W[kr]
;B[jr]
;W[ks]
;B[ns]
;W[ms]
;B[mr]
;W[mq]
;B[ls]
;W[lr]
;B[ms]
;W[ps]C[Black gets nowhere.])
(;B[ks]C[This is the correct move that stops White making two eyes. ]
;W[pr]C[This is White's strongest response.]
;B[os]C[This stops the eye shape.]
(;W[ps]
;B[ns]C[This threatens to link to the black stone played on the edge.]
;W[ms]
;B[mr]
;W[or]
;B[ns]C[There is no eye here for White.])
(;W[ns]
;B[ps]
;W[lr]C[White is threatening to make a big eye]
;B[ls]
;W[ms]
;B[mq]C[This has to be here to stop two eyes. ]
;W[kr]C[It looks like  White can get an eye on the edge, but the lone black stone to the left stops it.]
;B[jr]
;W[js]
;B[ks]
;W[is]
;B[ir]
;W[hs]
;B[gs]C[The eye is false and White is dead.])))
