(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]
RU[Chinese]SZ[19]KM[7.50]TM[7200]OT[3x60 byo-yomi]
PW[Lee Sedol ]PB[AlphaGo]WR[9d]DT[2016-03-13]EV[Google DeepMind Challenge Match]RO[Game 4]PC[Seoul, Korea]WT[Human]BT[Computer]SO[https://gogameguru.com/]RE[W+Resign]
;B[pd]
;W[dp]
;B[cd]
;W[qp]
;B[op]
;W[oq]
;B[nq]
;W[pq]
;B[cn]
;W[fq]
;B[mp]
;W[po]
;B[iq]TR[po]C[The change of Q5 apparently changed AlphaGo's response. ]
;W[ec]
;B[hd]
;W[cg]
;B[ed]
;W[cj]
;B[dc]
;W[bp]
;B[nc]
;W[qi]
;B[ep]C[This move has never been seen before.]
(;W[eo]
;B[dk]C[It is difficult to say which is better.]
;W[fp]C[毫无道理，相当于黑D9肩冲，白在F5一带跳了一个。。。 此手当然应走左边。

It is impossible to understand the reason behind this move. It is as if black had played shoulder hit at D9 and white responded with a jump at F5. 

White should have simply responded on the left side instead.]
;B[ck]
;W[dj]
;B[ej]
;W[ei]
;B[fi]
;W[eh]
;B[fh]
;W[bj]
;B[fk]
;W[fg]
;B[gg]
;W[ff]
;B[gf]C[Black is already leading.]
;W[mc]
;B[md]
;W[lc]
;B[nb]
;W[id]
;B[hc]
;W[jg]
;B[pj]C[The ability of AlphaGo to access the board globally is extraordinary.]
;W[pi]
;B[oj]
;W[oi]
;B[ni]
;W[nh]
;B[mh]
;W[ng]
;B[mg]
;W[mi]
;B[nj]
;W[mf]
;B[li]
;W[ne]
;B[nd]
;W[mj]
;B[lf]
;W[mk]
;B[me]
;W[nf]
;B[lh]
;W[qj]C[With the experience of the 3rd game, it can be understood that Lee Sedol's stratey here is to first take territory then invade.]
;B[kk]
;W[ik]
;B[ji]
;W[gh]
;B[hj]
;W[ge]
;B[he]
;W[fd]
;B[fc]
;W[ki]C[It is Lee Sedol's turn to play an unexpected move. Actually...]
(;B[jj]C[K10 is the losing move, AlphaGo is tricked here.]
;W[lj]
;B[kh]
;W[jh]C[There is still the possibility of ko.]
(;B[ml]
;W[nk]
;B[ol]
;W[ok]
;B[pk]
;W[pl]
;B[qk]
;W[nl]C[AlphaGo seemed to have gone crazy here, these exchanges worsened the situation for black.]
;B[kj]C[Black finally decided against the ko.]
;W[ii]
;B[rk]
;W[om]
;B[pg]
;W[ql]C[White has turned the game around, the move 78 forced mistakes out of AlphaGo.]
;B[cp]C[The following series of exchanges are probably computer's way trying to turn the game around.]
;W[co]
;B[oe]
;W[rl]
;B[sk]
;W[rj]
;B[hg]
;W[ij]
;B[km]
;W[gi]
;B[fj]
;W[jl]
;B[kl]
;W[gl]
;B[fl]
;W[gm]
;B[ch]
;W[ee]
;B[eb]
;W[bg]
;B[dg]
;W[eg]
;B[en]
;W[fo]
;B[df]
;W[dh]
;B[im]
;W[hk]
;B[bn]
;W[if]
;B[gd]
;W[fe]
;B[hf]
;W[ih]
;B[bh]
;W[ci]
;B[ho]
;W[go]
;B[or]
;W[rg]
;B[dn]
;W[cq]
;B[pr]
;W[qr]
;B[rf]
;W[qg]
;B[qf]
;W[jc]
;B[gr]
;W[sf]
;B[se]
;W[sg]
;B[rd]
;W[bl]
;B[bk]
;W[ak]
;B[cl]
;W[hn]
;B[in]
;W[hp]
;B[fr]
;W[er]
;B[es]C[uch move is unthinkable for human.]
;W[ds]
;B[ah]C[Again...]
;W[ai]
;B[kd]
;W[ie]
;B[kc]
;W[kb]
;B[gk]
;W[ib]
;B[qh]
;W[rh]
;B[qs]
;W[rs]
;B[oh]
;W[sl]
;B[of]
;W[sj]
;B[ni]
;W[nj]
;B[oo]
;W[jp]C[Lee Sedol's move 78 will certainly be remembered in the history, this game will probably be the last game won be human in such competition between human and computer.])
(;B[jn]
;W[lg]
;B[kg]
;W[kf]
;B[kj]
;W[le]))
(;B[kj]C[This is the correct response.]
;W[gi]
;B[fj]
;W[ii]
;B[ij]
;W[jh]
;B[gj]C[There is nothing white can do locally.]))
(;W[eq]C[E3 is simply fine.]))
