(;GM[1]FF[4]SZ[19]
GN[pressing while middle is already occupied]
PC[http://senseis.xmp.net/?ThicknessExamples]AP[GoWiki:2009]
DT[2009-04-22]
C[Diagram from http://senseis.xmp.net/?ThicknessExamples

pressing while middle is already occupied]
PL[W]

AB[rb][ic][lc][rc][qd][rd][ce][pe][rf][rg][cp][qp][iq][lq]
AW[qb][dc][oc][qc][nd][re][ch][qh][rh][ck][qk][eq][oq]

;W[do]C[W1]MN[1]
;B[co]C[B2]MN[2]
;W[dn]C[W3]MN[3]
;B[cn]C[B4]MN[4]
;W[dm]C[W5]MN[5]
;B[dr]C[B6]MN[6]
;W[po]C[W7]MN[7]
;B[qo]C[B8]MN[8]
;W[pn]C[W9]MN[9]

;
)
