This came up in a game yesterday, and I thought it was a fun tesuji. You need to use the weakness of one of w's two center groups (e13 and l8) to catch the other. Navigate (or try again) to see how to respond if w saves the other group.
(;
;AB[bb][bc][bg][bn][br][cc][cg][ch][cj][ck][cl][cm][cn][cp][cq][cr][dk][dn][dq][ds][ec][el][em][er][es][fg][fk][gd][gg][gh][gi][gk][gl][gr][hd][he][hh][hm][hq][hr][id][ig][ii][ij][ik][im][in][io][ip][ir][jc][jg][jl][jm][jp][kc][kg][lb][lf][lp][lq][mh][ml][mo][mp][nf][nh][nj][nk][nl][no][of][oh][oo][pb][pc][pf][pg][pi][pj][pk][po][qc][qd][qe][qf][qk][ql][qo][qp][re][rk][rm][rn][sd][sk][sl]
;AW[ac][an][ar][bd][bf][bl][bm][bo][bp][bq][bs][ce][co][dh][dj][dl][do][dp][ee][ef][eg][ej][ek][ep][eq][fh][fi][fl][fm][fo][fp][fr][fs][ge][gf][gm][gp][gq][hf][hg][hl][hp][if][ih][il][iq][jd][jf][jh][ji][jj][jk][jn][jo][kd][kl][km][lc][lk][ln][lo][mb][mc][mj][mk][mn][mr][nd][ne][ng][nn][nq][ob][oc][og][oi][ol][on][oq][pd][pe][ph][pl][pn][pp][qg][qh][qi][qj][qm][qn][qq][rb][rc][rd][rf][rg][rj][ro][rp][rr][se][sf][sh][sq]C[Black to catch a big white group.
Please start wtih the tesuji.]
(
;B[ld]
;W[kf]C[Tesuji!]
(
;B[li]
(
;W[ll]C[CHOICE]
;B[le];W[fd];B[fc];W[en];B[dm];W[gj];B[hi]
(
;W[dg]
(
;B[di];W[bi];B[ci]
(
;W[af]
(
;B[cd]
(
;W[cf];B[de]
(
;W[dd]
;B[ed]C[RIGHT]
)
(
;W[ed];B[dd];W[df];B[ff]C[RIGHT]
)
)
(
;W[dd];B[cf];W[ed];B[ff]C[RIGHT CHOICE]
)
)
(
;B[cf]C[RIGHT]
;W[cd]
(
;B[ed]C[RIGHT]
;W[dd]
)
(
;B[df];W[ed];B[ff];W[dc];B[db];W[de];B[ag];W[ic]
(
;B[hc];W[ib];B[jb]
)
(
;B[ib];W[gc];B[hc];W[gb];B[fb];W[ie];B[ke];W[je];B[hb]
)
)
)
)
(
;W[cf];B[ae];W[af];B[ad];W[be];B[ad]
(
;W[bk];B[bj];W[aj];B[am];W[al];B[ai];W[ah];B[ag]C[RIGHT CHOICE]
)
(
;W[ag]C[If white makes a desperate effort to connect underneath...]
;B[ah]
(
;W[aj]
(
;B[am];W[bh];B[bj];W[ai];B[ak];W[ah];B[ao]C[RIGHT]
)
(
;B[bj];W[ak];B[bh];W[ai];B[bk]C[RIGHT CHOICE
You have just enough liberties
]
)
)
(
;W[ai]
(
;B[am];W[al];B[bj];W[aj];B[ak];W[bk];B[bh]C[RIGHT CHOICE
You have just enough liberties]
)
(
;B[bh];W[ak];B[aj];W[bj];B[bk]C[RIGHT CHOICE
B just enough liberties again.]
)
)
(
;W[ak];B[am];W[ao];B[bk];W[al];B[aj];W[am];B[ai]C[RIGHT]
)
)
)
)
(
;B[cf];W[ae];B[di];W[ed];B[ff]C[RIGHT CHOICE w dies]
)
)
(
;W[di];B[dg];W[eh];B[ae];W[af];B[ad];W[be];B[ad];W[ag];B[ah]
;W[bi];B[ci];W[bj];B[bk];W[ak];B[am];W[al];B[aj];W[ai];B[bh]C[RIGHT CHOICE]
)
)
(
;W[le]C[CHOICE]
;B[lj]
(
;W[lm]
;B[ko]C[ w dies]
)
(
;W[ll];B[mm];W[lm];B[ko]C[w dies ]
)
)
)
(
;B[lg]
(
;W[le];B[li];W[ll];B[mm];W[lj]C[w lives]
)
(
;W[ll]
(
;B[le]C[RIGHT w group on the left dies. Play m16 first, then m11 (or Navigate) to kill. ]
)
(
;B[ke];W[je];B[le]C[RIGHT w group on the left dies. Play m16 first, then m11 (or Navigate) to kill. ]
)
)
)
(
;B[lh];W[le];B[ll]
(
;W[lm];B[ko];W[kh];B[lg];W[li]C[ w lives]
)
(
;W[kh];B[lg];W[li]C[w lives]
)
)
)
(
;B[li]C[A key move.]
;W[ll]
;B[ld]C[RIGHT The key move. Play this move first to see how to kill w's group in the upper left.
]
)
(
;B[ke]C[Not the right move....]
(
;W[je]C[W can save everything by playing at M15. But what if w plays here instead? ]
;B[ld];W[kf]
(
;B[le];W[lg];B[kh];W[lh];B[ki];W[li];B[kj];W[kk];B[lj];
)
(
;B[li]C[The key spot. ]
;W[ki];B[lh];W[le]
(
;B[lj]C[CHOICE RIGHT ]
)
(
;B[ll];W[lj];B[kk]C[CHOICE RIGHT]
)
)
)
(
;W[le]C[If white plays here, she is safe.]
(
;B[je];W[kf];B[li];W[lg];B[kh];W[ll];B[ld];W[mf]
)
(
;B[me];W[ld];B[je];W[kf];B[li];W[ll];B[ie];W[lg];B[kh];W[mf]
)
)
)
(
;B[kh];W[kf]
(
;B[ll];W[li];B[ki];W[kj];C[RIGHT w dies]
)
(
;B[lm];W[ll];B[mm];W[li];B[ki];W[kj];
;W[lj]C[w lives]
)
(
;B[ko];W[ll]
(
;B[mm];W[li];B[ki];W[kj];
;W[lj]C[w lives]
)
(
;B[lj];W[kn];B[mm]C[RIGHT w dies]
)
)
(
;B[ki]
(
;W[ll];B[mm];W[kj];B[lj]
)
(
;W[kj]
(
;B[lj];W[ll];B[mm];W[ko];B[lm]
)
(
;B[ll];W[lm];B[ko];W[li];C[RIGHT w dies]
)
)
)
(
;B[li];W[ll];B[mm];W[lj];B[ki];W[kj]C[w lives]
)
)
(
;B[kf];W[je]
(
;B[ll];W[li];B[kk];W[kj];
;W[kh];B[lj];W[lh];B[kk];C[w lives]
)
(
;B[li];W[ll];B[mm];W[lj]C[w lives]
)
(
;B[lm];W[ll];B[mm];W[li]C[w lives]
)
)
)
