(;GM[1]FF[4]SZ[19]AP[SmartGo:3.1.1]CA[utf-8]
GN[Game_004]
PW[AlphaGo Master]
PB[AlphaGo Zero]
KM[7.5]
RE[B+R]
RU[Chinese]
TM[7200.0]OT[3x60 byo-yomi]MU[0];B[dp];W[pp];B[dd];W[pd];B[nc];W[qf];B[qq]
;W[qp];B[pq];W[oq];B[or];W[nq];B[nr];W[mq];B[mr];W[lq];B[fc];W[cn];B[cj]
LB[dk:A][ck:B]
C[This is where we start to see some variety in this 20 game set. Zero played this pincer in 5 out of 10 games, and lost twice, so this move has a relatively low winning rate. Otherwise, it could pincer at A or B. ]
(;W[fp]LB[cq:A][cn:B]
C[Master plays this double kakari in most of the games. In this board position, the lower side is small, so jumping into the corner at A is bad for White (see var). White plays on the lower side with 20, but is going to continue with moves that strengthen White's stone at B. ]
(;B[fo]
C[Black wants to build on the left side, so it plays an attachment against White's stone on the lower side. If Black had played an attachment on the left, Black would have ended up facing towards the right (see var). ]
(;W[eo]TR[fp]
C[White 22 is a very unusual move, in that White is offering to sacrifice the marked stone that White just played. Locally this has to be bad, but in this position the lower side is relatively small, so it is feasible. The natural move for White is to save the marked stone (see var). ]
;B[ep];W[en];B[gp];W[fq];B[gq];W[er]
C[I discussed some possible variations for White's kosumi at 28 in my commentary for game 2 of this set. White 28 is the good shape move here, and White is going to get a squeeze from the corner. ]
;B[gr];W[cp];B[dq];W[cq];B[dr]
C[This sequence in the LL corner occured in 8 of the 10 games in which AGZero had Black, with Black's pincer stone at A or B. Locally, this is good for Black, and I would not suggest that people should learn this as a joseki. In this board position the lower side is relatively small, and because of that I would say that it is an even game, with White's influence working towards the left side.]
LB[dk:A][cj:B];W[cr]
C[In this 20 game set, Master played 34 every time in the 5 games with this board position. This is a big move that settles the White group. ]
;B[dg]LB[dg:A][pc:B]
C[Zero played at A only once out of 5 games. In the other 4 games it played at B. ]
;W[pk];B[ne];W[cf]
C[White 38 is one way White can attack Black's UL corner. ];B[df];W[cd];B[cc]
;W[ce];B[cg]
(;W[bc]
C[Instead of playing the normal sequence to live (see var), Master is setting up a ko. I find this to be a bit unreasonable, and it put White in a difficult position. ]
;B[cb];W[dc];B[de];W[db];B[bb];W[ab]
(;B[ba]LB[bd:A]
C[This will be a ko in either case, but 51 is better for Black than cutting at A (see var). ]
;W[da];B[bd]
(;W[kc]
C[White has ko threats, so why not play ko? (see var)];B[ec]
C[Black 55 captures the corner. ]
(;W[rp]
C[White has no aji in the UL corner (see var), and I think the game already looks good for Black. ]
;B[rq];W[ke];B[pb]
(;W[qc]
C[White should have played the peep before answering at 60 (see var). ];B[lc]
C[61 was a sharp move that secured life for Black on the side while taking away White's eyespace. ]
(;W[ng]
C[At this point the game is already looking bad for White, but I would want to make a more direct answer to Black's attachment (see var). ]
;B[kd]
(;W[ld]
C[Covering is not good (see var), so it is correct for White to cut here. ]
;B[jd];W[mc];B[lb];W[nd];B[mb];W[md];B[oc];W[od];B[je]TR[ge:ie][ch:ci][bj]
C[Imagining the marked lines as borders for Black's territory in the upper left, Black has about 60 points here, so when adding Black's other territories Black has a total of about 75. In order to catch up to that, White must surround the right side on the 7th line. There is some room for Black to expand the upper side into the center and get about 20 points more while White is making the right side territory. In short, this is a position from which Black should be able to win provided it doesn't mess up. ]
;W[ll];B[lj];W[ki];B[oo];W[ln];B[kj]
(;W[nj]
C[White cannot capture the Black group (see var). ];B[mk];W[nl];B[ji]
C[If Black can get some extra territory in the center while White surrounds the right side, that will be enough for Black to win. ]
;W[jj];B[nk];W[ok];B[kp];W[kq]
(;B[ni]
C[Zero chose not to play the simple move (see var). ];W[kh];B[jk];W[ij];B[op]
;W[qn]
(;B[ik]TR[ji][oo:op][kp]
C[All of the marked stones are participating in this fight, making it scary for White. However, Black's push at 95 is a dangerous move, and I don't understand how it is supposed to work, or why Zero declined to take the easier path to victory (see var). ]
(;W[hj]
C[White 96 lost White's finally opportunity to fight it out by cutting Black (see var). ]
;B[oj];W[pj];B[mj];W[oh];B[ml];W[mm];B[km];W[lm];B[kl]
C[Now the Black group is safe, and Black is winning. ];W[sq];B[sr];W[sp]
;B[ig];W[ih];B[jg];W[jh];B[jp];W[lp];B[hh];W[kn];B[fn];W[in];B[mh];W[fj]
;B[oi];W[pi];B[qr];W[rr];B[rs];W[fm];B[lf];W[mg];B[lg];W[go];B[gn];W[gm]
;B[hn];W[il];B[io];W[hm];B[ho]
(;W[nb]
C[White tried to attack Black's group, but persisting with a cut in the center will just cause a bigger loss for White (see var), so White has run out of good moves. After this Master will perform a suicide ritual of self-destructive moves before resigning. ]
;B[ob];W[ds];B[fr];W[do];B[eq];W[ci];B[bi];W[hg];B[gh];W[jf];B[if];W[ad]
;B[be];W[bh];B[di];W[kb];B[nh];W[na];B[oa];W[ic];B[qb];W[rb];B[qa])
(;W[lh];B[nh];W[li];B[og];W[of];B[ph];W[nf];B[qg];W[rf];B[jn];W[jm];B[im]
;W[lk];B[kk];W[in];B[hk];W[gk];B[im]LB[lh:A][nh:B]
C[When White tries to kill Black by cutting at A, Black can force with B and reduce White's right side territory. After this, White will not have enough valid ko threats. ]
))
(;W[kk];B[mo];W[lo]LB[mo:A]
C[Black A seems to add some aji that might help Black, but now Black must choose between continuing on the lower side, or in the center (2 vars for Black's move). ]
(;B[lp];W[mp];B[kl];W[lk];B[lm];W[ml];B[mm];W[km];B[kn];W[mn]
C[When Black tries to break through by immediately playing an atari at A, it does not go well for Black. White B and C are miai, and White has won this fight. 
]
LB[kl:A][nm:B][jl:C])
(;B[oj];W[pj];B[mj]
C[If White will answer in the center, this exchange will change what happens on the lower side (2 vars for White's move). ]
(;W[mh];B[lp];W[mp];B[kl];W[lk];B[lm];W[ml];B[mm];W[km];B[kn];W[mn];B[nm]
;W[jl];B[ol]TR[mh][mj][oj:pj]LB[kl:A]
C[With the marked exchange extending Black's liberties, now Black can break through with A. Black captures with a ladder, and this ends in a collapse for White. ]
)
(;W[ml];B[hj];W[ii];B[jh];W[hi];B[jg];W[mh];B[gj];W[gi];B[fj];W[gg]
C[When White connects at A, Black does not have room to make eyes. Black cannot capture White in the center, and this ends in a collapse for Black. ]
LB[ml:A]))))
(;B[ml];W[mm];B[ik];W[hj];B[oj];W[pj];B[mj]LB[ml:A][ik:B]
C[It is safer for Black to start by pushing through at A, and then pushing at B. The game variation ended up something like this when White missed a chance to start a final fight. ]
))
(;B[jk];W[ij];B[ik];W[kk];B[jh]LB[jk:A][hj:B][lh:C]
C[The simple way for Black to play is to escape with A, and White is in more trouble in the center than Black. Black can capture next with B or C. ]
))
(;W[jj];B[km];W[lm];B[kk]LB[jj:A][op:B][km:C]
C[White's strongest move is the hane at A. With the threatened cut at B, White must answer the peep at C and Black can escape. ]
))
(;W[jd];B[ld];W[jf];B[ie];W[je];B[mg]
C[Black is already alive, and White has an eyeless shape, so Black will be able to erase White's center while attacking, and this is good for Black. ]
))
(;W[ld];B[lb];W[md];B[nd];W[ng];B[jd];W[kd];B[qb]LB[ld:A][og:B]
C[White A is a big move that I would want to play, but it is not so good when White ends up with heavy and weak shape. Black will simply make a living shape on the side. Compared with the game sequence, White has gained in territory by erasing the upper side, but has weak shape on the outside, with Black looking to attach at B next. ]
))
(;W[md];B[nd];W[qc];B[ng];W[ph];B[kg];W[mc]LB[md:A][nd:B]
C[White should have played the peep at A, and the exchange for Black B makes a big difference in the eyespace for both groups. This is better than the game for White. ]
))
(;W[ad];B[be];W[bf];B[bg];W[ae];B[eb]LB[ad:A][be:B][eb:C]
C[If White starts a ko with A, Black can force with B to create a safely dead shape before playing C to win the semeai. Thus means that the whole corner is Black territory with good aji. ]
))
(;W[ad];B[ac];W[go];B[fn];W[bc];B[oo];W[op];B[ac];W[fm];B[gn];W[bc];B[pg]
;W[be];B[ec];W[ca];B[pf];W[qg];B[qh];W[pe];B[ph];W[pb];B[pm]LB[ad:A][go:B][ec:C][pg:D]
C[White can start a ko at A, and has ko threats at B. However, when White finally wins the ko the profit is just territory, with no potential to attack Black's outside group. Black can force at C, so Black has a strong position on the outside. All Black needs to do is play a big point such as D as it's ko threat, and this is a good result for Black. ]
))
(;B[bd];W[ca];B[ac];W[ba];B[aa];W[go];B[fn];W[ab]LB[bd:A][ca:B]
C[If Black cuts at A, White can make a ko with B. ]))
(;W[de];B[ee];W[dc];B[ed];W[bc];B[cb];W[bb];B[db];W[bg];B[bh];W[ag]LB[de:A]
C[Starting by pushing through at A, White can make life with this forcing sequence. Once White has invaded the left side to start this fight, it is best for White to simply live as in this diagram.]
))
(;W[go];B[eo];W[gp];B[gn];W[hn];B[hm]LB[fo:A][go:B]
C[When Black plays the attachment at A, White normally will answer at B, and we can see that Black is building on the left side in this natural sequence. This is an example of how an attachment towards the right is often played when the left side is important. ]
))
(;B[dn];W[dm];B[en];W[co];B[ep];W[bq]TR[lq]
C[When Black attaches on the left with A, this is an example of how White can choose a joseki that forces Black towards the lower side. White's marked wall reduces the value  of Black's outside thickness. ]
LB[dn:A]))
(;W[cq];B[cp];W[dq];B[ep];W[bp];B[bo];W[bq];B[co];W[fq];B[ce]
C[Since the lower side is small compared to the left side. invading the corner at A is bad for White even though this is a joseki. ]
LB[cq:A]))

