(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]
RU[Japanese]SZ[19]KM[0.00]
PB[Black to play and kill]AW[lq][mq][nq][pq][qq][lr][or][pr][qr][rr][ls][ms][ns]AB[lp][mp][np][op][pp][qp][rp][kq][oq][rq][kr][sr][ks][qs][rs]
(;B[ps]C[Often to kill one pushes into the eye shape, however, here it is not fast enough.]
;W[os]C[However White can atari the three black stones, and 
Black cannot stop them being captured to give a second eye.]
(;B[ss]
;W[sq])
(;B[sq]
;W[ss]
;B[rs]
;W[qs])
(;B[nr]
;W[ss]
;B[rs]
;W[qs]))
(;B[nr]C[This is the correct first move here, setting White up for shortage of liberties.]
(;W[ps]C[This is self-atari.]
;B[os])
(;W[mr]
;B[ps]C[Now Black can push in.]
;W[os]
;B[nr])
(;W[sq]C[This doesn't make Black short of liberties.]
;B[sp])))
