(;GM[1]FF[4]SZ[19]AP[SmartGo:0.4.1.2]CA[UTF-8]
GN[167cx-v2]
PB[Black to play]
RU[Japanese]ST[2]
AB[pl][qm][np:nq][op][rq:rr][or:qr][os]
AW[nn:no][qo][mp:mr][rp][oq:qq][nr]
(;B[pp]
C[Playing the atari fails to get the black stones out.];W[qp];B[pn];W[po]
)
(;B[qp]
C[This throw-in does not work either.];W[pp];B[po];W[oo])
(;B[oo]
C[This does not work.];W[on];B[po];W[pn];B[qp];W[pp]TR[on])
(;B[pn]
C[And both this and the jump to its left also fail.];W[po])
(;B[po]
C[This is the correct move. It threatens the throw-in 
or the atari next, and Black either escapes to
capture the white group or captures it directly.]
(;W[pn];B[qp]
(;W[pp];B[qp])
(;W[qn]
C[This is White's strongest defence to save some white stones.]))
(;W[oo];B[pp];W[qp];B[pn]
C[Black escapes and the white group cannot live.])
(;W[qp];B[pn]
C[Again Black escapes, killing White.])))

