(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]
RU[Japanese]SZ[19]KM[0.00]
PB[Black to play and capture some white stones]
AW[rm][rn][rp][nq][oq][qq][rq][nr][pr][ns]AB[qm][qn][np][op][pp][qp][mq][pq][mr][ms]
(;B[os]C[This first atari leads to a series of ataris that leads to White losing some stones. 
White should just give up the four stones.]
(;W[or]
;B[qr]
;W[ps]
;B[qs])
(;W[qr]
;B[or]))
(;B[ps]C[This move sometimes catches White in bad shape
as it threatens a snap-back.]
(;W[or]C[White must not play here to stop the snap-back.]
;B[qr])
(;W[qs]C[This is the move that stops the snap-back.]
;B[or]
;W[os])
(;W[qr]C[Connecting here leads to the snap-back.]
;B[or]
;W[os]
;B[or])))
