(;GM[1]FF[4]SZ[19]
GN[Why is it a ko threat]
PC[http://senseis.xmp.net/?KoFightExampleFromAProGame3]AP[GoWiki:2009]
DT[2013-01-09]
C[Diagram from http://senseis.xmp.net/?KoFightExampleFromAProGame3

Why is it a ko threat]
PL[B]

AB[pd][bh][ci][bj][cj][dk][ek][fk][gl][cm][gm][an][cn][gn][in][qn][bo][co][do][go][cp][ep][fp][gp][hp][ip][qp][cq][oq][pq][br][dr][er][cs][es]
AW[dd][ch][bi][aj][dj][bk][al][cl][dl][bm][dm][hm][bn][dn][en][hn][jn][eo][ho][io][ko][dp][jp][np][op][aq][bq][dq][eq][fq][gq][hq][iq][nq][ar][as][bs]
CR[ch]
LB[cf:a][ck:b]

;B[cr]C[B1]MN[1]
;W[ai]C[W2]MN[2]
;B[bg]C[B3]MN[3]
;W[dh]C[W4]MN[4]

;CR[ch]
LB[cf:a][ck:b]
)
