(;GM[1]FF[4]SZ[19]AP[SmartGo:3.1.2]CA[utf-8]
GN[Game_003_annotated]
PW[AlphaGo Zero]
PB[AlphaGo Master]
KM[7.5]
RE[W+R]
RU[Chinese]
TM[7200.0]OT[3x60 byo-yomi]MU[0]MU[0]MU[0]
C[Commentary by Michael Redmond 9P, edited by Chris Garlock and Myron Souris. 
AG Zero and the Ke Jie version sort of resemble each other, in the way that they play around the 3-3 invasions, and there’s a ‘taste’ to their play that’s quite similar. That said, the Ke Jie version tends to jump into fights more quickly and that’s very exciting, but in the Zero version, there’s a lot of hidden reading, like we saw in Game 2. Just as Master did against human players, Zero is controlling the game to a much greater degree, and a lot of the reading is not actually coming out on the board. 
In this game, Master has black again and will be playing a lot of moves towards the center. So there are lot of stones floating around in the center of the board and looking kind of neat. I think Master had a good opening in this game and then there’s one move I really don’t like, that’s really the turning point of the game. And just like when I’m playing a formidable player, I find that just one move can turn things very sour quite quickly.]
;B[pd];W[dp];B[dc];W[pp];B[df];W[qc];B[pc];W[qd];B[qf];W[qe];B[pe];W[rf]
;B[jd];W[cn];B[dm];W[ch]
C[The first 16 moves were played every time that Master had Black in this 20 game set. ]
;B[qq]LB[nq:A][gp:B]
C[Finally, Master shows some variety, sometimes playing at A or B instead of 17.  I still find it disturbing that AGMaster is not performing as it did in the 60 game series against human players. The original Master could play different moves early in this same game sequence, and while I am not an expert at computer engineering, I still say that a different output indicates that the system is not the same as the AGMaster that we know from the previous game set. ]
;W[pq];B[qp];W[po];B[qo];W[pn]TR[qc]
C[Because of the marked joseki in the UR corner, the right side is relatively small. White extends at 22, giving some extra profit to Black in order to take sente, and this makes sense when the next move on the lower side is comparatively big. ]
;B[rm];W[iq]LB[jp:A]
C[Zero prefers to play low on the third line. In this 20 game set, board positions similar to this occurred five times, and Zero played high at A only once, that being the only game that Zero lost with White. ]
;B[io]
C[Humans also like to play from above like this, while Zero usually dives in a bit deeper. It's success with these moves that look good to human players was a reason for it's popularity. ]
;W[eg]LB[dd:A]
C[In game 1, I talked about the attachment at A that Zero likes to play. 26 is another move that Zero likes in this UR corner shape, and we will be seeing more of it in this game set. ]
;B[lp]TR[iq]
C[B27 is another move that is true to Master's style as I perceive it. Black threatens the marked stone While reducing White's potential on the side and preparing to attack White on the right. ]
;W[gp];B[mn]LB[mm:A][qr:B][or:C]
C[B29 is a tight move, and I would be thinking of playing at A. However, it is hard to say which might be better, with A being more active, and 29 being safer. White can play a hane at B, and follow with the hanging connection at C, which is usually sente. This would allow a potential counter-attack against Black on the lower side, in which case the tight move at 29 might be better for Black. ]
(;W[ej]TR[ef]
C[White should have pushed once at the marked point before protecting at 30 (see var). ]
;B[gn];W[ef]LB[ej:A][df:B]
C[White 32 is a big move that reduces Black's potential on the upper side, but it was played out of order. When White has already protected the cutting point at A, there is no reason for Black to save the stone at B, and Black can gain a tempo by playing away. ]
;B[dn];W[co]
(;B[mk]LB[nk:A]
C[Black cannot surround White in the lower right (see var), but still I find 35 to be too tight. I would play at A to put more pressure on White. ]
;W[ok];B[eq]
C[Black invades White's biggest potential territory. When compared to Zero, Master has a bias towards creating a moyo or outside thickness, but it actually likes territory as well. If Black can succeed with this invasion, Black has potential to take a lead in territory. ]
;W[ep];B[fq];W[fp];B[dq];W[fn]
C[White cannot kill the Black group in the corner, and now attacks Black's thin connection on the outside. ]
;B[fm];W[gm];B[hn];W[fl];B[em];W[go]
(;B[ci]
C[B 49 is a ladder-breaking move. Cutting immediately in the center would not be very good for Black (see var). ]
(;W[gl]
C[White needs a stone at 50 to stop Black from cutting (see var). ];B[ei]
;W[fi];B[bh];W[cg];B[di];W[bg];B[cm];W[eh];B[dj];W[im]TR[gn]LB[fj:A][ek:B]
C[White cannot kill the Black group on the left outright, and as we shall see, it becomes a ko in the game. White has a weak shape with potential cutting sequences starting with Black A or B, and with 60 White is reinforcing that weakness while threatening to capture the marked cutting stones. ]
(;B[jo]LB[im:A]
C[61 was a heavy move. Obviously Black is saving the cutting stones, but actually, Black is not in a position to attack and this became a small move when White got to attack first. Black should have lived on the left side (see var). The exchange of A for 61 was a big kikashi for White, and the stone at A played made an important difference in the center fighting later in the game. ]
;W[gq]
C[Fixing White's shape, White threatens to kill Black on the lower side. ]
;B[cq];W[bm];B[bl];W[bn]
(;B[bj]
C[67 is the correct move here (see var). ];W[ck];B[cl];W[dk];B[ek];W[fj]
;B[el];W[ah];B[ai]
(;W[ag]
C[There is no reason for White to connect here without taking the ko first. Black is going to win the ko anyway, so this mistake is not important (see var). ]
(;B[bk]
C[Black cannot connect the ko with 77 (see var). ];W[bi];B[en];W[fo];B[bh]
;W[bp];B[fk]
C[Black pushes out once before connecting the ko. This sets up a cut in the center. ]
;W[gk];B[bi];W[br]TR[jo]
C[Black has lived on the side, and White has captured the corner to make a territory of about 30 points. Does the marked Black stone look like an important move now? I would have preferred to use this move in the LL corner to make a living shape.  ]
;B[gj]TR[jo]
C[Black cuts in the center, making use of the marked stone after all. Still, it will be a lot of effort for a relatively small territory. ]
;W[hj];B[gi];W[fh];B[hi]
(;W[ii]
C[White's hane is an important move. White must not be too greedy here, and it is correct to offer some local profit to Black (see var). ]
(;B[ij];W[hh];B[hk];W[gh];B[hj];W[fc];B[bq];W[aq];B[bd]
C[Black is alive in the UL corner. ];W[ji];B[jj];W[ki]TR[im][jo]LB[il:B][kj:A]
C[Allow me to say for a third time that the marked exchange was a big kikashi for White. If Black plays away now, White can play at A, threatening to escape with B. ]
;B[kj];W[ld]
C[To take a quick look at the territory, White's LL corner is about the same as Black's center. The UR and LR corners also are about the same. Black has a living shape in the UL corner that will be smaller than komi. White seems to have an advantage on the upper side. The game looks promising for White. ]
;B[qb];W[rb];B[rg];W[pb];B[ob];W[pf];B[qg];W[qa];B[of]
C[The sequence to 115 is a joseki that we were seeing in the AGKeJie self-play set of games. ]
;W[lj]LB[lk:A][pg:B]
C[116 is a ladder-breaking move, so if Black answers at A, White will escape at B. ]
;B[li];W[lk];B[mj];W[ll]LB[im:A][il:B]
C[For a fourth time, I get to say how valuable the stone at A is for White. White gains a tempo by threatening to play at B. 
]
;B[hm];W[mi];B[lh];W[mh];B[lg];W[ml];B[mg];W[oi]
C[White's gain in this trade in the center was that Black's center territory has shrunk to less than 20 points, and White has close to a living shape with territory. White now has a big lead in territory, and Black must try to catch up on the upper side. ]
;B[hc];W[ed];B[dd];W[jg]LB[kf:A][nb:B]
C[Zero calmly secures some eye shape. White has good moves at A or B, and it will be difficult for Black to gain much on the upper side. ]
;B[ge];W[gb];B[hb];W[nb];B[nc];W[oa];B[oh];W[ni];B[pl];W[ol];B[pj];W[pi]
;B[if]
C[Master seems to be searching in vain for some way to attack White. Black's surrounding groups are not very strong, so Master is struggling. ]
;W[jf];B[je];W[gf];B[qi];W[ng];B[le];W[eb];B[db]LB[be:A][hf:B][fa:C]
C[White can make an eye with sente by playing at A, and another eye with sente by playing at B. With another potential eye at C, White is alive. ]
;W[pk];B[gd];W[fd];B[pm];W[om];B[qk];W[ce];B[be];W[de];B[bf];W[mc]TR[bd][ce][bf]
C[The marked exchange actually reduced White's eyespace, but when White plays at 164, Black's group is weak too. Black cannot attack yet. ]
(;B[nf]
C[It is hard to say which side is attacking here, with Black scrambling to connect everything up. If we assume that Black is safe, then there is a way for Black to attack White, but it is not happening yet (see var). ]
;W[ph];B[pg];W[hf];B[ig];W[ie]LB[gg:A][df:B][fb:C]
C[Squeezing with 170, White is making an eye at A while attacking the Black group. White is alive with a second eye at B or C. ]
;B[nn];W[on];B[nq];W[qm];B[ql];W[qn];B[rn];W[qr];B[rr];W[or];B[qs];W[np]
;B[mq];W[no]
C[White had no trouble making that second eye. ];B[he];W[id];B[ic];W[ih]
;B[hd];W[kr]
C[Now the endgame begins. By my calculation, White is ahead by about 2.5 points. ]
(;B[lr]
C[White's group in the upper left is alive (see var). ];W[ln];B[jr];W[ir]
;B[km];W[lm];B[do];W[cp];B[lb];W[mb];B[pr];W[oq];B[kq];W[me];B[kf];W[ie]
;B[mf];W[kb];B[jb];W[la];B[id];W[cf];B[fe];W[ee];B[kl]
C[Black 215 is 10 points, the biggest move at this time. ];W[bb];B[bc];W[kk]
;B[jk];W[cd];B[cc];W[af];B[ab];W[lo];B[kg];W[oj];B[qj];W[re];B[is];W[hs]
;B[js];W[hr];B[hg];W[gg];B[jh];W[rh];B[qh];W[sg];B[dh];W[dg];B[ff];W[fa]
;B[oc];W[mp];B[ko];W[nr];B[ka];W[lc];B[kc];W[ja];B[ia];W[ec];B[ca];W[ea]
;B[ka];W[ae];B[ad];W[ja];B[na];W[ma];B[ka];W[kn];B[jn];W[ja];B[nl];W[mo]
;B[ka];W[jq];B[ks];W[ja];B[ar];W[as];B[ka];W[jp];B[kp];W[ja];B[sf];W[se]
;B[ka];W[ba];B[cb];W[ja];B[fr];W[cr];B[ka];W[da];B[aa];W[ja];B[ap];W[ao]
;B[ka];W[jm]
(;B[ja];W[jl];B[bs];W[cs];B[gc];W[ga];B[hq];W[gr]TR[kl]
C[In the end, Master threw away several points when it allowed White to capture the marked stones. White is ahead even before komi. Even without that final loss, White was going to win by about 2.5 points.]
)
(;B[jl];W[ja];B[bs];W[cs];B[ka];W[ri];B[rj];W[sh];B[lb];W[mr];B[kb];W[ms]
;B[ne];W[md];B[nd];W[pa];B[kd];W[na];B[ls];W[lq];B[mq];W[os];B[ps];W[sj]
;B[sk];W[nh];B[og];W[kh];B[jg];W[al];B[ak];W[am];B[hp];W[hq];B[si];W[sf]
;B[sj];W[ga];B[ha];W[gc];B[fg];W[nq];B[lq];W[ip];B[ho];W[eo]
C[W+1.25 (2.5)]))
(;B[fe];W[ee];B[ff];W[hg];B[fg];W[ie];B[if];W[kh]LB[gg:A][jh:B][df:C][fb:D]
C[When Black tries to take away the eye at A, White can make one at B with this sequence. White's second eye is at C or D. ]
))
(;B[fe];W[ee];B[ig];W[ih];B[ff];W[hf];B[ie];W[ke]LB[fe:A][ig:B][ke:C]
C[Black A and B are both forcing moves that White cannot afford to ignore, and the White group cannot make two eyes. Black can't do this though, as Blackis in trouble on both sides when White cuts at C. ]
))
(;B[hh];W[ik];B[ih];W[ji]TR[im][jo]LB[hh:A][mn:B]
C[In this variation Black stubbornly refuses to trade with A, but White has good shape and eyespace in the center, and Black's B group now looks thin. With such a good position in the center, it will be relatively easy for White to handle the single weak White group on the left. Note that the marked exchange is playing a big role in making this a good result for White. This takes us back to my comment for Black 61, where I said it was a heavy move and that the exchange was an important kikashi for White. ]
))
(;W[ij];B[ii];W[jj];B[ig]
C[White is in trouble in the center and the left side, so this is good for Black. ]
))
(;B[bi];W[ak];B[al];W[bk];B[dl];W[dh]TR[dm]
C[This is a temporary seki, but of course the marked Black group can be captured, so the whole side becomes White's territory. ]
))
(;W[bi];B[en];W[fo];B[bh];W[ag];B[ak];W[bi];B[fk];W[gk];B[bh];W[bp];B[bi]
;W[br];B[gj]LB[bi:A][en:B][fk:C]
C[Obviously White should take once at A to start the ko, this is elementary. However,  with ko threats at B and C, Black can win the ko anyway, getting a result similar to the game. Technically Zero made a mistake in the game by not playing what I call the 'strongest' variation, but in actual play it made little difference. ]
))
(;B[ck];W[bj];B[ek];W[fj];B[bi];W[el];B[dl];W[al];B[ak];W[bk];B[am];W[aj]
;B[cj];W[al]LB[ck:A][fk:B]
C[When Black plays at A, it will probably become this ko, although both sides have some choices along the way. Black no longer has the potential to cut by pushing through at B, so this is an easy ko for White. ]
))
(;B[bm];W[in];B[kn];W[jo];B[gd]LB[bm:A][kn:B][gd:C]
C[Black should play at A to secure life for the group on the left, and then force with B to make shape in the center, sacrificing the cutting stones. After C, the game still looks about even. ]
))
(;W[dg];B[en];W[fo];B[gl];W[hm];B[fk]
C[Black can capture the cutting stone with a ladder. ]))
(;B[gl];W[hm];B[gk];W[in];B[ek];W[fj];B[fk];W[ho]LB[gl:A][gk:B][ho:C]
C[Black can cut at A and extend at B to capture the cutting White stone with a net, but when White captures at C this is bad for Black. Black's groups in the lower half of the board are too thin altogether. ]
))
(;B[pl];W[ol];B[pk];W[nn];B[mm];W[ok]LB[pl:A][pk:B]
C[When Black cannot enclose the White group, Black A and B become moves in a small area of the board. This is not working for Black, and it is better to attack from a distance as in the game. ]
))
(;W[ef];B[de];W[ej]LB[ef:B][ej:A][df:C]
C[When White is going to protect with a move such as A, it is best to play the forcing move at B first. If White starts with A, the value of Black's stone at C will decrease, and Black will play away if White plays B later. ]
))

