(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]
RU[Japanese]SZ[19]KM[0.00]
PB[Noir]AB[jd][pd][pj][jp][pp]
;B[dd]
;W[qn]
;B[np]
;W[mp]C[One of the usual erosions; 4 possible answers ]
;B[mq]
;W[lq]
;B[lp]C[Strongest]
;W[mo]
;B[lo]C[Always extend from the cutting side]
;W[nq]
;B[mr]
(;W[oq]C[Hamete (trick play)]
;B[op]
;W[lr]
;B[mn]
;W[no]
(;B[oo]
;W[nn]
;B[nm]
;W[on]
;B[pn]
;W[om]
;B[ol]
;W[pm]
;B[qm]C[possible because of the stone at Q10]
;W[pl]
;B[ql]
;W[pk]
;B[ok]
;W[qk]
;B[rk]
;W[qj]
;B[qi]
;W[rj]
;B[ri]
;W[sj]
;B[si]
;W[po]
;B[sk]
;W[pn]
;B[rn]
;W[qo]
;B[qp]C[Last possible mistake]
;W[ro]
;B[rp]
;W[so]
;B[sn])
(;B[nn]C[If black dont see the ladder, this is ok too]
;W[oo]
;B[pn]
;W[nr]
;B[po]
;W[ms]
;B[mq]
;W[mr]
;B[on]))
(;W[mn]C[The normal joseki]
;B[nr]
;W[ln]
;B[jn]
;W[on]
;B[pm]
;W[pn]
;B[qp]))