(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]RU[Chinese]SZ[19]KM[7.50]GN[Gu-Li-vs-Lee-Sedol-20140223]PW[李世石]PB[古力]WR[九段]BR[九段]DT[2014-02-23]EV[MLily Gu vs Lee Jubango]RO[Game 2]PC[Shanghai, China]SO[http://gogameguru.com/]C[The second game of the MLily Gu vs Lee Jubango took place in Pinghu (on outskirts of Shanghai), on February 23, 2014.This time Gu Li held black and Lee Sedol played white.Lee won the first game, so it became more important for Gu to even the series by winning this game.Many people expected that Gu Li would have something of an advantage in this match, because most of the games will be played in China. However, it doesn't seem like Lee Sedol is affected by that so far, since the different food and environment don't seem to bother him.Actually, it looks like Gu Li is under quite a bit of pressure from his fans and the Chinese media. They're very enthusiastic about this match, and I suspect that this could be creating more psychological pressure and may be distracting Gu.The time limit for these games is 3 hours and 55 minutes, with 1 minute x 5 times byo-yomi. It's traditional to subtract 5 minutes from the 4 hour total, because of the 5 x 1 minute periods.There's no lunch break scheduled for these games, but food is provided and the players are free to get up and eat whenever they want, throughout the game. Anyway, let's have a look at their second game of the jubango.]RE[白胜0.50];B[pd];W[dd];B[qp];W[op]LB[dd:2][pd:1][dp:A][op:4][qp:3][dq:B]C[The immediate approach at White 4 was an unusual move, which has rarely been seen in top pros' games recently. It's much more common for White to occupy the last empty corner, at A or B for example. However, White 4 is by no means new.Because Gu Li likes to play the Mini Chinese and Micro Chinese openings, Lee played to avoid Gu's favorite opening. Therefore, White 4 can be viewed as part of the metagame between Lee and Gu.](;B[eq]LB[cp:A][op:4][eq:5]C[Since White didn't claim the last open corner with White 4, Black claimed it for himself with Black 5. The placement of Black 5 on the 3-5 point facing White 4 is significant. Black aims to pincer White 4 soon, especially if White plays at A next.](;W[qq]LB[op:4][eq:5][qq:6]C[Since Black played elsewhere after White 4, taking a bite out of the corner with the attachment at White 6 is natural for White.];B[cp](;W[cj]LB[cj:8][cp:7]C[White took a big point, but it was a questionable move. Because of White 8, Gu started the game with a nice opening.];B[rq];W[pq];B[qm]LB[qm:11][ro:C][kq:B][pq:10][rq:9][rr:A]C[Gu returned to the lower right corner, and the opening was already favorable for Black with the moves up to Black 11. The pattern in the lower right corner is relatively modern and the negotiations there are settled for the time being.From White's perspective, his three stones are safe because A and B are miai. So there's no particularly compelling reason for White to continue in the lower right corner immediately.From Black's perspective, playing Black 11 at C would provoke White B, and Black would still feel like playing another move in the lower right afterwards. Black 11 is a flexible, fast paced move.](;W[qf]LB[qf:12]C[Lee took sente and approached at White 12.](;B[qh]LB[qf:12][qh:13]C[In addition to starting a pincer attack on White 12, Black 13, assisted Black's three stones in the bottom right corner.Since the right side isn't especially interesting anymore, Black intended to take sente from the negotiations in the top right and play a big move in one of the more open areas on the board.];W[qc]LB[qc:14][qf:12][qh:13]C[Lee chose the simplest and most common continuation. With White 14, White is offering to trade White 12 for the corner territory.];B[qd];W[pc];B[od];W[rd];B[re];W[rc];B[qe];W[nc]LB[nc:22][pc:16][qc:14][rc:20][od:17][qd:15][rd:18][qe:21][re:19][qf:12][qh:13]C[The moves up to White 22 formed a basic star point joseki. White traded White 12 for the corner territory, and Black was able to take sente, as intended.](;B[lq]LB[lq:23]C[Black's pincer at Black 23 was unusual, but it was a very nice move in this situation.](;W[rr];B[rp]LB[rp:25][rr:24]C[It's not clear whether the exchange of White 24 for Black 25 favored Black or White. Since Lee wanted to play simply and settle his group, he may have decided that making this exchange was reasonable.Evaluating the pros and cons of this exchange would require a great deal of analysis and the difference can be quite subtle. Since this exchange didn't turn out to be particularly important in the game and there are many more interesting variations to consider, we'll forgo that analysis here.];W[mp]LB[mp:26]C[Lee wanted to lead things towards a peaceful game, so he played to settle his group with the solid haengma of White 26.](;B[jp]LB[cl:B][jp:27][nr:A]C[The knight's move at Black 27 was surprising and demonstrates Gu Li's extraordinary intuition for the opening. It's a very flexible move which makes miai of A and B for Black.](;W[mq]LB[mq:28]C[Defending at 28 was necessary.];B[cl]LB[nc:22][pc:16][qc:14][rc:20][dd:2][od:17][pd:1][qd:15][rd:18][qe:21][re:19][qf:12][qh:13][cj:8][cl:29][qm:11][cp:7][jp:27][mp:26][op:4][qp:3][rp:25][eq:5][lq:23][mq:28][pq:10][qq:6][rq:9][rr:24]C[The opening up to Black 29 looks better for Black. All I can say is that Gu Li's sense of play in the opening is superior to Lee Sedol's.];W[ej]LB[ej:30][el:C][cn:A][eo:B]C[Jumping at White 30 reinforced White's moyo in the top left, while creating possible followups (e.g. A-C) for White in the lower left.];B[el];W[dq]LB[ej:30][el:31][cn:A][dq:32][dr:B]C[This attachment was a probe. After Black reinforced his moyo with Black 31, potential moves like the invasion at A became less interesting. Therefore, it was a good time to probe with White 32.White isn't worried about making Black's position stronger and erasing possibilities (like A), because Black's already reinforced at Black 31. On the other hand, if White probes here later on, Black might resist powerfully with B and capture any group White tries to establish in this area.In summary, this is an opportune moment to probe, because Black's moyo has already been reinforced, but isn't yet strong enough for Black to resist aggressively.](;B[dp]LB[dp:33][dq:32]C[Answering at Black 33 was inevitable, and it confirms that White's probe was well timed.](;W[fc]LB[fc:34][nc:A]C[This knight's enclosure was questionable, because the left side is weak and it's hard for White to develop the top. Since White 34 and A are both low, White's potential at the top of the board is limited.];B[cf]LB[fc:A][cf:35][cj:B][ej:C]TR[cl][el][cp][dp][jp][eq]C[Approaching with a move like Black 35 is generally bad if there are already opposing stones like A and B reinforcing the position. However, it was good in this situation, partly because Black was already quite thick in the bottom left.Even though Black 35 is outnumbered locally, Black can aim to use his power in the lower left to turn the tables on White's stones at B and C. Black just needs to be able to withstand White's initial attack for long enough to bring his power to bear.];W[ce];B[df](;W[ch]LB[ce:36][df:37][ch:38]TR[cj][ej]SQ[cf]C[Extending to White 38 looks small, but it was an important move. 38 is a key point for the eyespace of both the marked groups.];B[gf](;W[gd]LB[gd:40][gf:39]C[White 40 is a vital point and this sort of move is usually good because it prevents Black from pressing White down by playing at 40 himself.];B[eh]LB[gd:40][gf:39][eh:41]TR[ch][cj][ej]C[This knight's move was very good in good combination with Black 39. Gu didn't just run away, but struck at the vital point and counter-attacked White's marked group.];W[gj];B[gh]LB[gh:43][gj:42]TR[df][gf][eh]C[After Black 43, we can see clearly that Black created depth for his group, by making a box shape, while starting to turn White's group into a stick. Because of this, the balance of power shifted in Black's favor.];W[ij];B[gl]LB[fj:A][ij:44][gl:45]TR[df][gf][eh][gh][el]C[Black used his newfound power to exploit White's thinness with Black 45. White's left side group became weaker and a potential cutting point at A was exposed. Black 45 also expanded Black's moyo in the bottom left, so it was a very good move.];W[er]LB[er:46]C[Since White was already slightly behind, he needed to do something about the lower left corner, before it became too big. The asking move at White 46 was a good way to start.](;B[dr]LB[dr:47]C[Black secured the corner with Black 47.];W[fq];B[ep];W[hp](;B[jn]LB[jn:51][ep:49][hp:50][fq:48]TR[jp][lq]C[White tried to settle his group at the bottom up to White 50. Black 51 was a dual purpose move which defended Black's marked stones and attacked White's group simultaneously.](;W[hm]LB[hm:52]C[White 52 was a surprising and interesting move, typical of Lee Sedol's style of play.];B[hn];W[gn](;B[ho]LB[im:A][gn:54][hn:53][ho:55]C[Head butting with Black 55 was questionable and it led to an unsatisfactory result in the game. It would have been better for Black to counter-hane with A.];W[ds];B[cr];W[go];B[gm];W[ip];B[jo];W[jq];B[kq];W[jr]LB[fj:A][gm:59][go:58][jo:61][ip:60][jq:62][kq:63][cr:57][jr:64][ds:56]C[White settled very easily at the bottom up to White 64 and it was good for White.Black was still focusing on the wedge at A. Because of that, he thought that being able to reinforce with Black 59 and take sente to play A would be good enough. Unfortunately for Black, the moves in the actual game demonstrated the flaw in this plan.White caught up at this point and the game became even again.](;B[fj]LB[fj:65][kj:A][hm:B]TR[hn][jn][ho][jo][jp][kq][lq]C[Gu took sente and wedged with Black 65, all according to plan. However, this wedge wasn't as powerful as it looked.Earlier on, we looked at another variation where Black took sente and capped at A. Attacking White's entire group instead of cutting it in two would have been a better strategy in this game.However, because of the cutting stone at B, White's marked stones were a little thin now and attacking on a large scale wasn't as easy as it would have been if Black had played more decisively at the bottom.](;W[fi]LB[fi:66][fj:65][fk:A][gm:B]C[The atari at A didn't work well anymore after Black played at B, so defending on the other side with White 66 was White's best option.];B[fk];W[ei];B[gi];W[fh];B[fg];W[eg];B[ef](;W[bf]LB[bf:74][ef:73][eg:72][fg:71][fh:70][ei:68][fi:66][gi:69][fj:65][fk:67]C[The hane at White 74 was an unexpected good move. White was able to complete his corner territory and look after his weak group at the same time.It looks as if Gu Li didn't consider this possibility when planning to wedge at Black 65.];B[bg];W[be];B[cg];W[bh]LB[be:76][bf:74][ag:A][bg:75][bh:78][dh:B][fj:C]C[White 78 made miai of A and B, so White was already alive. The is was a satisfactory result for White and it turned out that Black's wedge at C wasn't as strong as it had seemed at first.];B[ie](;W[gr]LB[ie:79][gj:B][hj:D][ij:A][hm:C][nm:E][gr:80]C[Up to Black 79, White was able to manage both his weak groups, and consolidate the top left corner, without sustaining any serious damage. The game was reversed at this point.Black 79 aimed to develop a large moyo for Black and swallow up White's stones at A-C on a large scale. It also helped to reduce White's potential at the top. Simply capturing a stone by playing at D instead would be a bit slow.White 80 looked small, but it was actually very big. White can now reduce or invade Black's center area without having to worry about his own weaknesses. For example, White doesn't have to worry about Black playing around E anymore.After White 80 the game became favorable for White.](;B[lj]LB[ie:79][lj:81][gr:80]C[Black 81 showed us Gu Li's keen intuition for playing in the center. Gu may have felt that the center area was neither strong nor solid, so he played Black 81 to take control of this area.];W[ll](;B[nk]LB[lj:81][nk:83][ll:82]C[Lee's reduction at White 82 was a good response and Black defended the right side with Black 83.];W[jl];B[im];W[ki];B[kj];W[li];B[mj](;W[jj]LB[ki:86][li:88][jj:90][kj:87][lj:81][mj:89][nk:83][jl:84][ll:82][im:85]C[White's reduction was going well, but White 90 was heavy. It gave black a good opportunity to attack White in the center.Lee had a specific plan in mind when he played White 90, but he'd made a small oversight, as we'll see in a moment.];B[jh];W[ji];B[mm]LB[jh:91][ji:92][jj:90][mm:93]C[Gu started to attack White's center group with Black 91 and Black 93. Gu specializes in attacking, and Lee's very good at managing weak groups, so the game became more exciting at this stage.];W[mi];B[ni];W[nh];B[oh](;W[ng]LB[ng:98][nh:96][oh:97][mi:94][ni:95][mm:93]C[Extending at White 98 was the right move for White, but Black was also happy to create a big territory on the right side.];B[og];W[hi]LB[og:99][hi:100]C[Lee had been aiming at White 100 when he played at A (White 90 in the game). However, it looks like Lee overlooked something when reading the upcoming ko fight.];B[hh];W[ih];B[ig];W[hg];B[ii]LB[hg:104][ig:103][hh:101][ih:102][hi:100][ii:105]C[This ko was inevitable after White 100.];W[oi];B[nj];W[ih];B[gg];W[jg]LB[gg:109][jg:110][ih:108][ii:105][oi:106][nj:107]C[After exchanging a ko threat at White 106, White cut at White 110 to make the ko bigger. Everything was still going according to Lee's plan.];B[ii];W[of](;B[pf]LB[of:112][pf:113][jg:110][ii:111]C[White 112 was a nice ko threat and Black had to answer.];W[ih];B[ed];W[ec];B[ii](;W[pg]LB[ec:116][ed:115][pg:118][ih:114][ph:A][ii:117]C[White chose the ko threat at White 118, instead of A, because he was sensitive toward the territory on the right side.];B[ph];W[ih];B[de](;W[cd]LB[cd:122][de:121][jg:C][pg:118][ih:120][ph:119][hi:B][jj:A]C[Defending at White 122 was necessary, and this is what Lee had overlooked earlier. When he played at A (White 90), he thought that he could simplify the game and consolidate his advantage by winning the ko from B through to C. Unfortunately for Lee, he misjudged the effectiveness of Black's ko threat at Black 121.];B[ii](;W[ml]LB[cd:122][ii:123][ml:124]C[There were no good ko threats left, so Lee played here, but it wasn't good enough for White.];B[hj];W[nl];B[ol];W[om];B[pl]LB[hj:125][ml:124][nl:126][ol:127][pl:129][om:128]TR[hg][jg][ih][hi]C[The result up to Black 129 was very successful for Black and the game was reversed again. White's moves at the marked points were all wasted, and they helped to make Black's position stronger in the center.];W[me];B[ag];W[dh];B[bk]LB[me:130][ag:131][dh:132][bk:133][pl:129]C[Lee played at White 130 to support his center group, but it didn't make any points.Black 133 was a nice sente endgame move.];W[dg];B[lo];W[hk];B[gk];W[pe];B[rf];W[mc];B[jc](;W[hc]LB[hc:142][jc:141][mc:140][pe:138][rf:139][dg:134][bk:133][gk:137][hk:136][lo:135]C[White 142 was a mistake. Lee might have thought that the game was still even, but actually White was already slightly behind.];B[kr];W[kh](;B[jf]LB[hc:142][jf:145][kh:144][kr:143]C[Black 143 was very big and suddenly White's stones at the bottom became thin and weak.White 144 was the beginning of a delicate endgame sequence and Black 145 was the best response.];W[ih](;B[oc]LB[oc:147][jf:145][ih:146][kh:144]C[Black had to fight the ko in the center, because the game was still quite close, even though Black was leading by 2-3 points.];W[ob];B[jh];W[kn];B[ln];W[ih];B[fp];W[gp];B[nm]LB[ob:148][oc:147][ih:152][jh:149][hl:B][nm:155][kn:150][ln:151][fp:153][gp:154]C[Gu wanted make White's ko threat at 150 bad, by playing the cut at Black 155. It seemed to be a good idea at the time, because cutting also prevents White from connecting at B and attacking Black's bottom group later.];W[if];B[sr](;W[nr]LB[if:156][nm:155][nr:158][sr:157]C[White 158 was the only move.](;B[hf]LB[hf:159][nr:158]C[White was alive after White 158, so Black went back to the top with Black 159.];W[ig];B[kg];W[hi];B[pb];W[nb];B[ii];W[jh];B[he];W[je];B[cs](;W[js]LB[nb:164][pb:163][he:167][je:168][hf:159][ig:160][kg:161][jh:166][hi:162][ii:165][cs:169][js:170]C[The atari at Black 169 was a double sente endgame move. The game up to here was still slightly better for Black. Black was winning by about 1.5-2.5 points at this stage.Defending White 170 was the right move.];B[es];W[fr];B[ic]LB[ic:173][je:168][fr:172][cs:169][es:171][js:170]C[Coming back to defend at Black 173 was necessary, after White finished exchanging endgame moves at the bottom.];W[on];B[no];W[mo];B[nn];W[oo];B[ik];W[jk];B[qr]LB[ic:173][ik:179][jk:180][nn:177][on:174][mo:176][no:175][oo:178][qr:181]C[The game was still close up to here, but Gu Li had maintained his lead. Black 181 was another big endgame move.];W[lp];B[kp];W[qn]C[Lee resisted with White 184 and this attachment was characteristic of Lee's style. It's hard to say whether this White 184 is correct or not, but it's difficult for black to answer.Lee's fierce endgame moves apply psychological pressure to his opponents and induce them to make mistakes. White 184 can be viewed as an expression of Lee's fighting spirit in the endgame.](;B[pm]LB[pm:185][qn:184][kp:183][lp:182][qr:181]C[Lee resisted with White 184 and this attachment was characteristic of Lee's style. It's hard to say whether this White 184 is correct or not, but it's difficult for black to answer.Lee's fierce endgame moves apply psychological pressure to his opponents and induce them to make mistakes. White 184 can be viewed as an expression of Lee's fighting spirit in the endgame.Gu chose to respond with Black 185 in the game.];W[np];B[ko];W[ls](;B[pn]LB[pm:185][pn:189][qn:184][ko:187][np:186][ls:188]C[White lived with White 181 and and Black captured White 184 with Black 189. White was able to take sente, but he had to pay for it with 184, which is what makes Lee's endgame unconventional.];W[en];B[hr];W[hs];B[bj](;W[dm]LB[bj:193][dm:194][en:190][pn:189][hr:191][hs:192]TR[dg][eg][bh][ch][dh][fh][ei][fi][cj][ej]C[Black 193 was a nicely timed move and White 194 helped White's marked group indirectly.];B[dn];W[em];B[dk];W[dj];B[bi];W[ci];B[eo];W[fn];B[cm]LB[bi:199][ci:200][dj:198][dk:197][cm:203][dm:194][em:196][dn:195][fn:202][eo:201]C[Black 195 was another nice endgame tesuji. Black's endgame up to here was great and Gu was still leading by about 1.5 points.];W[pr];B[rs];W[il];B[hl];W[oe](;B[ke]LB[ke:209][oe:208][hl:207][il:206][cm:203][pr:204][rs:205]C[Black 209 was big, but it was questionable.];W[kf];B[jd];W[ib]LB[ib:212][jd:211][ke:209][kf:210]C[White 212 was a big reverse sente endgame move. White caught up a little more and the game became very close.];B[jb];W[hb];B[jf];W[lf];B[sd](;W[qb]LB[hb:214][ib:212][jb:213][qb:218][rb:A][sd:217][jf:215][lf:216]C[Answering at White 218 was necessary. If White doesn't answer, Black will attach at A to reduce White's corner territory in sente.];B[nd];W[md];B[lb];W[ah];B[ck]LB[lb:221][qb:218][md:220][nd:219][je:A][ah:222][ck:223]C[Black 223 was another mistake. It was worth 3 points, but connecting at A was bigger and Black would have still won by half a point if he'd played there.];W[fe];B[ff];W[io];B[qg];W[pf](;B[ee]LB[hd:A][ee:229][fe:224][ff:225][pf:228][qg:227][ck:223][io:226]C[White should have played White 226 at A and fought the ko. Black 229 was too small. It was only worth two points because White was able to play at A in sente.Black 229 was the losing move.];W[je];B[dc];W[cc];B[db];W[cb];B[kd];W[hd]LB[cb:234][db:233][cc:232][dc:231][hd:236][kd:235][ee:229][je:230][hi:A][gj:C][ik:B]C[Black couldn't win the ko fight at White 230, because there was a double ko at A and B. Since Black couldn't afford to let it become a real ko at C, the double created unlimited ko threats for Black.Black lost half a point here, because White was able to force at 236 in sente.];B[id];W[lm];B[mn];W[jm];B[in]LB[hd:236][id:237][jm:240][lm:238][in:241][mn:239]C[Black lost another 1/3 of a point because of White's sente exchanges at White 238 and White 240.];W[lc];B[ja];W[ia];B[fd];W[km]LB[ia:244][ja:243][lc:242][fd:245][km:246][in:241]C[Black 245 was another small mistake, which lost another 1/3 of a point.White 246 was worth slightly more than two points and the game was decided here.In the end, White won by half a point.];B[af];W[fm];B[ek];W[ae];B[ps];W[os];B[qs];W[po];B[qo];W[ge];B[kc];W[ne];B[lr];W[mr];B[ma];W[mb];B[rg];W[na];B[la];W[sc];B[se];W[ai];B[aj];W[ks];B[hm];W[kk];B[fs];W[jf];B[ok];W[gs];B[ds];W[pp];B[le];W[ik];B[hi];W[mk];B[lk];W[fo];B[fl];W[dl]LB[la:265][ma:261][na:264][mb:262][kc:257][sc:266][ae:250][ge:256][le:279][ne:258][se:267][af:247][jf:274][rg:263][ai:268][hi:281][aj:269][ek:249][ik:280][kk:272][lk:283][mk:282][ok:275][dl:286][fl:285][fm:248][hm:271][km:246][fo:284][po:254][qo:255][pp:278][lr:259][mr:260][ds:277][fs:273][gs:276][ks:270][os:252][ps:251][qs:253];B[ld]LB[hi:B][jj:A]C[White won by just half a point!At first, the result of the game was reported as White by 1.5 points in the Go media, including Go Game Guru, because many pros who were watching the game counted it as White by 1.5 points.However, because this jubango is being played under Chinese rules, Black gets an extra point for playing both the first and last move. It wasn't enough to change the result, but it made the game closer.Gu Li got off to another good start in the opening, but Lee Sedol reversed the game after settling both his weak groups (at the bottom and on the left) without sustaining any significant damage.White A was a mistake, and Gu was able to attack White's center group. In addition, Lee misjudged the implications of the ko fight at B and the game was reversed again.Gu's endgame was fine almost until the end, but he made several small mistakes and lost a won game.Since Lee Sedol won the second game as well, he's already ahead 2-0 in the match. He'll be able to play more comfortably in the next game, and that will be another advantage for Lee in this series.Lee's opening wasn't good, but he caught up in the middle game as usual. He misjudged the situation in the center and fell behind again, but eventually he won with his magical endgame tactics.Lee's endgame is different to that of other top pros. His moves in the endgame are fierce and are backed up by deep reading. Lee's unconventional moves and constant probing make the endgame harder than usual for his opponents. This intense psychological pressure can cause his opponents to make mistakes and Lee reverses many games in the endgame because of this.On the other hand, Gu Li has likely suffered quite a bit of psychological damage after losing this game. That's because Gu maintained his lead throughout most of the endgame, but made several of small and unbelievable mistakes right at the end.He must have been under a great deal of pressure. Not just because he was playing Lee, but because most of the Go fans and reporters at the venue were cheering for him. He may have suffered from a lapse in concentration or got distracted towards the end of the game.In general, top pros don't make many mistakes in the endgame and today's game was abnormal for Gu. I hope he can find a good solution for dealing with Lee's endgame in game 3.I hope you'll be able to understand and enjoy this game better with this commentary, and be able to gain a better sense of the turning points in the game.This commentary will be expanded upon and will become part of our upcoming book on Lee Sedol and Gu Li's jubango: http://gogameguru.com/lee-sedol-vs-gu-li-go-book/If you have any questions or comments, or corrections (even if they're minor typos), please feel free to leave a comment. Your questions and comments will help us to create the best book we possibly can.Thanks, Commented by Younggil An 8p http://gogameguru.com/])(;B[jm];W[km];B[je]LB[je:3][jm:1][km:2]C[Black 1 is sente, and is a good exchange to make now, in light of further possible endgame moves.Next Black should connect at Black 3. If he'd done so, he still would have won by half a point.]))(;W[sc];B[qb];W[rb];B[ra];W[se];B[sb]LB[ra:4][qb:2][rb:3][sb:6][sc:1][se:5]C[Block at White 1 is a mistake. Black can start a ko with the moves up to Black 6, which would be a disaster for White this late in the game.]))(;B[ib];W[hb];B[ke];W[kf];B[jd]LB[hb:2][ib:1][jd:5][ke:3][kf:4]C[Black should have exchanged Black 1 for White 2 first, then Black would have maintained his winning position up to Black 5.]))(;W[cn];B[dm];W[dn];B[ci];W[bi];B[dj]LB[bi:5][ci:4][dj:6][dm:2][cn:1][dn:3]TR[dg][eg][bh][ch][dh][fh][ei][fi][ej]C[Jumping to White 1 would be too greedy. Black can counter-attack up to Black 6 and White's marked group will die.]))(;B[fn];W[qo];B[rn];W[ro];B[so];W[rm];B[sn];W[rs];B[qs];W[sp];B[sq];W[rl]LB[rl:12][rm:6][fn:1][rn:3][sn:7][qo:2][ro:4][so:5][sp:10][sq:11][qs:9][rs:8]C[Black can tenuki and defend the left side with Black 1, which is also big. However, White will counter with White 2 to White 12, which starts a capturing race inside White's territory.];B[rk];W[qk];B[rj];W[ok];B[pk];W[pj];B[qj];W[pn];B[oj];W[sm];B[sp];W[pp];B[ss];W[rr];B[rs];W[pr];B[ql];W[ps];B[sl]LB[oj:9][pj:6][qj:7][rj:3][ok:4][pk:5][qk:2][rk:1][ql:17][sl:19][sm:10][fn:A][pn:8][pp:12][sp:11][pr:16][rr:14][ps:18][rs:15][ss:13]C[Liberties count here and Black 1 is the tesuji which which saves Black from disaster. However, White's still able to squeeze 8 points out of Black in sente, up to Black 19. In contrast, Black A is worth 5 points, so Black decided not to tenuki in the game.If Black played Black 1 at 2, White would win the capturing race after playing atari at White 10.]))(;B[pr];W[or];B[rs];W[np];B[ko];W[ls];B[ks];W[lr]LB[rn:A][ko:5][np:4][lr:8][or:2][pr:1][ks:7][ls:6][rs:3]C[If Black tries to counter-attack White's group with Black 1 and Black 3, White can still live up to White 8 and Black needs to come back and defend at A in gote.]))(;W[id];B[es](;W[fr];B[js];W[ir];B[hq]LB[id:1][hq:6][fr:3][ir:5][es:2][js:4]C[If White doesn't defend at the bottom, his group dies up to Black 6. There's no way for White to live now.])(;W[fs];B[fr]LB[id:1][fr:4][es:2][fs:3]C[White might might think about creating a ko with White 3, but White doesn't have enough ko threats to win this ko.])(;W[hr];B[fr]LB[id:1][fr:4][hr:3][es:2]C[Falling to the vital point with White 3 doesn't work either. White's still dead after Black 4.]))(;W[es];B[gs](;W[fr];B[js];W[ir];B[is];W[hr];B[hs];W[hq]LB[hq:9][fr:3][hr:7][ir:5][qr:A][es:1][gs:2][hs:8][is:6][js:4]C[Connecting at White 1 is careless. Black 2 strikes at the vital point and White doesn't have a good response. The best White can do is beg for life up to White 9. However, White has lost practically all his territory at the bottom and Black can also bully White's lower right group at A later.White would lose the game if this happened.])(;W[hs];B[hr](;W[is];B[ls](;W[rs];B[js];W[ks];B[ir];W[fs];B[js]LB[hr:4][ir:10][qr:A][es:1][fs:11][gs:2][hs:3][is:5][js:8][ks:9][ls:6][rs:7]C[If White ataris at White 3, Black will exchange Black 4 for White 5, before revealing his double threat tesuji at Black 6. The moves up to White 11 are forced and when Black 12 recaptures the ko (at 8), White should resign.The timing of Black 6 is important. Black should wait to see how White answers Black 2 and Black 4, before playing Black 6. If Black exchanges Black 6 for White 7 too early, he may unnecessarily give up a big endgame move at A.Black 12 at Black 8])(;W[fs];B[qr];W[pr];B[rs];W[no];B[nq];W[ms];B[mr];W[lr]LB[no:11][nq:12][oq:D][hr:4][lr:15][mr:14][pr:9][qr:8][es:1][fs:7][gs:2][hs:3][is:5][ls:6][ms:13][ns:B][os:C][ps:A][rs:10]C[White can defend the lower left group with White 7, but Black 12 is a tesuji and White still has to fight a ko up to White 15.If White plays White 13 is at A, the result is still ko after Black B, White 3 and Black 14. If White 13 is at D, White dies after Black C.]))(;W[fs];B[is]LB[hr:4][es:1][fs:5][gs:2][hs:3][is:6][js:A]C[Capturing a stone at White 5 still leads to ko after Black 6 makes miai of connecting at A and starting a ko at 2.]))))(;B[qr];W[pr];B[rs];W[no]LB[no:4][pr:2][qr:1][rs:3]C[If Black continues attacking with Black 1, White can make a living shape with White 2 and White 4.]))(;W[rs];B[ks](;W[js];B[nr];W[mr];B[ms];W[or];B[nq]LB[nq:8][mr:5][nr:4][or:7][js:3][ks:2][ms:6][rs:1]C[If White answers at White 1, as usual, Black 2 is a double threat tesuji and White finds himself in great danger up to Black 8.])(;W[mr]C[If White answers here to save this group, ];B[hr]LB[nm:C][fp:A][gp:B][hr:4][mr:3][ks:2][rs:1]C[If White defends the bottom right group with White 3, Black hits White's vital point at Black 4, and White's lower left group dies. This is why Black exchanged A for B before cutting at C earlier.])))(;B[hf];W[jd];B[id];W[ic];B[kd];W[jb];B[kc];W[kb]LB[jb:6][kb:8][ic:4][kc:7][id:3][jd:2][kd:5][hf:1]C[If Black falls back at Black 1, attaching at White 2 is still a good endgame move. White can connect along the edge up to White 8, which is quite big.]))(;B[ih];W[jd];B[id];W[ic]LB[ic:4][jc:A][id:3][jd:2][ih:1]C[If Black connects at Black 1, White can cut Black at White 2 and capture White A. There's no way for Black to capture White 2.]))(;W[lr]LB[lr:1]C[White should have played at White 1. This move is bigger than it looks and the game's still close if White plays here. Black's still slightly ahead though.]))(;W[io];B[hj];W[in];B[il];W[jm];B[ik];W[ln];B[jk];W[lm];B[nd];W[mc];B[le]LB[mc:11][nd:10][le:12][hj:2][ik:6][jk:8][il:4][jm:5][lm:9][in:3][ln:7][io:1]TR[of][qf][jg][ng][pg][nh][ji][ki][li][mi][ij][jj]SQ[jn][jo][jp][kq][lq]C[White 1 looks like it could be a ko threat, but Black would still ignore it and capture at Black 2. Black 6 is a good move which makes miai of 7 and 8.Black and White trade the marked groups up to Black 12, but the result is good for Black. White's center group is much bigger than Black's five stones at the bottom are.]))(;W[if];B[cd];W[dc];B[bd]LB[dc:3][bd:4][cd:2][de:A][if:1]C[Originally, Lee thought that Black would have to defend at 1, rather than playing A. Lee's plan was to capture at White 1 now, but Black 2 and Black 4 are more powerful than Lee initially expected.](;W[dh];B[he];W[bc];B[af]LB[bc:3][he:2][af:4][dh:1]TR[be][ce][bf]C[This trade looks bad for White. White didn't actually make very much territory in the center, he only made his group strong. However, losing the marked stones up to Black 4 is a big loss.])(;W[hf];B[dg];W[bk];B[di];W[dh];B[dj];W[eg];B[ek];W[eh];B[ck]LB[hf:1][dg:2][eg:7][dh:5][eh:9][di:4][dj:6][bk:3][ck:10][ek:8]TR[ie]C[If White plays at White 1 to cut off Black's marked stone stone, his left side group will be captured up to Black 10. Continuing...];W[ge];B[ff];W[bc];B[af];W[cc];B[ae];W[pe];B[rf];W[nd]LB[bc:3][nd:7][ae:4][ge:1][pe:5][ff:2][rf:6]C[White can build a huge territory spanning the top and the center up to White 7, but the game's still better for Black. Letting Black capture the group on the left side was too big and Black takes the lead.])))(;W[ph];B[pg];W[ih];B[de];W[cd]LB[cd:5][de:4][pg:2][ih:3][ph:1]C[If White ataris at White 1 instead he can win the ko fight, but this ko threat loses points and it looks like White was reluctant to play like this. Continuing...];B[ii];W[qg];B[pi];W[ih];B[if];W[kh];B[ag];W[dh];B[bk];W[dg];B[ic]LB[ic:11][if:5][ag:7][dg:10][qg:2][dh:8][ih:4][kh:6][ph:A][ii:1][pi:3][bk:9]C[After White 4, Black would have to fall back at Black 5, because the ko threatens Black's whole top left group and he doesn't have any more local ko threats.Even though White wins the ko fight at with White 6, the game becomes even again up to Black 11. That's because White's ko threat at A loses 4 or 5 points.]))(;B[hj];W[ph];B[pg];W[qg];B[pi];W[pf]LB[pf:6][pg:3][qg:4][ph:2][pi:5][hj:1]C[White's wedge at White 2 is a nice tesuji and White can squeeze Black up to White 6. Next...];B[oj];W[nd];B[rg];W[rf];B[sf];W[rh];B[sg];W[qi];B[ph];W[pj];B[oi](;W[nf];B[ri];W[ic]LB[ic:14][nd:2][nf:12][rf:4][sf:5][rg:3][sg:7][ph:9][rh:6][oi:11][qi:8][ri:13][oj:1][pj:10]C[White can connect his weak group with White 2 and Black can connect under with Black 3. White 6 to White 10 are forcing moves, after which White should defend at White 12. The result up to White 14 is good for White and White's still in the lead.])(;W[ri];B[nf];W[ne];B[mf];W[oe];B[le]LB[nd:2][le:17][ne:14][oe:16][mf:15][nf:13][rf:4][sf:5][rg:3][sg:7][ph:9][rh:6][oi:11][qi:8][ri:12][oj:1][pj:10]TR[ng][nh][ji][ki][li][mi][ij][jj][jl][ll]SQ[od][pd][qd][qe][re]C[Connecting at White 12 is also conceivable, but then Black will cut in sente with Black 13 and reinforce his position with Black 17. It's a big trade between the marked groups. Black captures the center stones and White captures the top right, but the result is better for Black.This means that White's connection at White 12 is too greedy.])))(;W[oi];B[nj];W[og];B[mh];W[ph];B[mg];W[qi];B[me]LB[me:8][mg:6][og:3][mh:4][ph:5][oi:1][qi:7][nj:2]TR[ji][ki][li][mi][gj][ij][jj][jl][ll][hm]C[If White tries to reduce the right side more aggressively, with White 1 and White 3...Black will cut White's group in two with Black 4 to Black 8. Black's center group is now in danger, so this is too risky for White.]))(;W[ih];B[ji];W[jh];B[jj];W[ke]LB[ie:A][ke:5][hf:B][ih:1][jh:3][ji:2][jj:4]C[Jumping at White 1 would have been better. If Black tries to attack White with Black 2 and Black 4, White can easily manage his stones up to White 5.Black needs to look after his stone at A now, because the cutting point at B has been exposed. The game is still slightly better for White.]))(;B[jk];W[pl];B[pm];W[nl]LB[jk:1][nl:4][pl:2][pm:3]TR[gj][ij][hm]C[If Black plays at Black 1, to isolate the marked stones, White will reduce the right side with White 2 to White 4. It won't be easy for Black to attack this group afterwards.]))(;B[nm];W[nk];B[pk];W[lk];B[lm];W[mh]LB[jg:A][mh:6][oh:B][lk:4][nk:2][pk:3][lm:5][nm:1]C[Jumping to Black 1 is also conceivable, but then White can reduce the center more easily than in the actual game, with White 2 to White 6.It's hard for Black to attack this group severely, because these stones are light and flexible. White 6 makes miai of A and B. Either move would secure eyespace by creating a box shape in the center.]))(;W[pl];B[pm];W[nl];B[om];W[mj];B[mn];W[kj];B[mr];W[nr];B[fp];W[gq];B[fr];W[gr];B[es];W[hr];B[pj]LB[kj:7][mj:5][pj:16][nl:3][pl:1][hm:C][om:4][pm:2][mn:6][fp:10][gp:B][gq:11][fr:12][gr:13][hr:15][lr:A][mr:8][nr:9][es:14]TR[hn][jn][ho][jo][jp]C[For example, imagine that White immediately springs to action on the right side with a reduction at White 1. If the game continues up to White 7, White's lower right group has been isolated.White has to answer Black 8 with White 9, which (as we discussed earlier) prevents White's connection at A. Neither of White's groups can be captured, but it's good enough for Black to bully White and force him to live small up to White 15. White's already lost a considerable number of points here.Moreover, Black can now capture two cutting stones at B at any time. This means White's cutting stone at C becomes almost useless. Because of this, Black's marked stones become stronger than before and Black can start to attack White's center group with Black 16.These moves are intended to clearly illustrate the value of White 80 in the actual game. I wouldn't expect Lee Sedol to actually play like this.]))(;W[dg];B[bf];W[bd];B[bi];W[ci];B[ck]LB[bd:3][bf:2][dg:1][bi:4][ck:5]TR[eg][ch][fh][ci][ei][fi][cj][ej]C[If White simply plays White 1 to live, the descent at Black 2 makes miai of 3 and 4. White can't defend the corner at White 3, because Black 4 and Black 5 are a nice combination and White's marked group dies.Therefore, White would have to play White 3 at 4 instead, but then the corner is left open to reduction or invasion later on. This would be quite annoying for White.]))(;W[fk];B[fi];W[ek];B[gk];W[fl];B[fm];W[dl];B[em];W[dm];B[cm];W[dn];B[cn];W[en];B[dk];W[ck];B[fn];W[fo];B[eo];W[dj];B[gp];W[fp];B[il]LB[bf:B][fi:2][dj:19][ck:15][dk:14][ek:3][fk:1][gk:4][dl:7][fl:5][il:22][cm:10][dm:9][em:8][fm:6][cn:12][dn:11][en:13][fn:16][eo:18][fo:17][fp:21][gp:20][gq:A]C[If White ataris at White 1, he can still break through Black's shape with the moves up to White 9. However, Black 10 is a powerful move and Black can prevent White's groups from connecting in the continuation up to Black 18.White has to capture a stone with White 19 and then Black 20 is a nice asking move. If White defends at White 21, Black will have time to defend too, at Black 22. Now both of White's groups are unsettled, so A and B are miai and Black will be able to capture one or the other.If White plays White 21 at A, Black 21 and 22 will be miai, so Black will play at B immediately and White's left side group will still die.]))(;B[mr];W[gr];B[nr];W[nm]LB[nm:4][fp:C][fr:B][gr:2][lr:A][mr:1][nr:3]C[In the actual game right now, White can connect under at A if he wants to.Black might consider playing the hane at Black 1 and, if White responds at 3, Black can harass White's lower left group with B or C.However, White would calmly reinforce his lower left group with White 2 and would answer Black 3 with White 4. It's quite hard for Black to continue attacking White's group after White 4, so Black didn't play like this.Instead of Black 1, Black might prefer to develop his potential on the right and intimidate White by playing around 4 later on.]))(;B[im](;W[io];B[jo](;W[hl];B[in];W[gm];B[go]LB[hl:4][gm:6][im:1][in:5][go:7][ho:A][io:2][jo:3]TR[hp][fq][er]C[Black 1 is better than A (Black 55 in the game). White 2 and White 4 are an interesting combination, but White's marked stones are still separated and they end up in danger. This result is good enough for Black.])(;W[in];B[hl];W[gm];B[fk];W[fj];B[hq];W[gq];B[hr]LB[fj:8][fk:7][hl:5][gm:6][im:1][in:4][io:2][jo:3][gq:10][hq:9][hr:11]C[White can try to live by cutting at White 4, but it's very difficult to make two eyes after Black 11.]))(;W[jr](;B[iq];W[ir];B[hq];W[ds];B[cr];W[hr];B[gq];W[gr];B[fp];W[kq];B[kj]LB[kj:12][fp:10][gq:8][hq:4][iq:2][kq:11][cr:6][gr:9][hr:7][ir:3][jr:1][ds:5]TR[ch][cj][ej][gj][ij]C[Sliding with White 2 looks like the best solution for White, but Black will be able to accumulate power with the moves up to Black 10.White has to defend in gote with White 11. This gives Black time to cap at Black 12, attacking White's marked group while starting to develop a large framework on the right side.The fact that Black's top left group has already become relatively strong makes it easier for Black to attack from this direction.])(;B[jq];W[ds];B[cr];W[ir];B[kr];W[gr]LB[im:1][jq:3][cr:5][gr:8][ir:6][jr:2][kr:7][ds:4]C[Black 3 and Black 7 are natural moves, which are usually good. In this case though, White lives in style up to 8 and feels very comfortable with the result.]))))(;W[jq];B[iq];W[ip];B[jr];W[jo];B[kq];W[ko];B[io];W[hq];B[hr];W[gr];B[ho]LB[hl:D][gm:C][hm:A][in:B][ho:12][io:8][jo:5][ko:7][ip:3][hq:9][iq:2][jq:1][kq:6][gr:11][hr:10][jr:4]C[White 1 is the first thing most players would think of to try to settle White's group at the bottom. However, the moves up to Black 12 show that it doesn't work well for White.However, imagine that White already has a stone on the board at A (White 52 in the game). In that case White would be able to atari at B and capture Black's cutting stone after Black 8. This was one of Lee's aims when he played White 52 in the actual game.]))(;B[fj];W[fk];B[fi];W[ek];B[gk];W[fl];B[fm];W[em];B[fn];W[dl]LB[fi:3][fj:1][kj:A][ek:4][fk:2][gk:5][dl:10][fl:6][em:8][fm:7][fn:9]TR[hp][fq][er]C[It's too early to wedge at Black 1 right now. White will respond with White 2 to White 8 and break through Black's shape. Even though Black can play Black 7 and Black 9 in the process, he's still not thick enough to use that power effectively against White's marked stones at the bottom.However, we can see from this sequence that if Black's able to place more stones within the vicinity of Black 7 in sente, then cutting at Black 1 becomes a stronger aim.Therefore, a better strategy for Black is to attack White's marked stones first and look forward to cutting at Black 1 or attacking at A later, depending on how White plays at the bottom.]))(;B[fq];W[cq];B[fr];W[bp];B[bo];W[br];B[ap];W[aq]LB[bo:5][ap:7][bp:4][aq:8][cq:2][fq:1][br:6][fr:3]C[If Black extends at Black 1, White can easily create a ko fight in the corner. Even if Black wins the ko, White will be satisfied to gain two moves in a row in another other part of the board. White has too many possible ko threats, so Black can't play like this.]))(;W[eh]LB[df:B][ff:D][gf:C][ch:A][eh:1]TR[cj][ej]C[The situation in this game is a little bit unusual and I think it would have been better for White to look after his left side group with White 1.The merit of White 1 is that it creates 'depth' for White's weak group (marked) while reducing the depth of Black's group. Just like with territory, only two stones are required to create a base on the side (and just one in the corner). However, when playing in the center, you need four stones to create a base. You need to create a box shape to secure eyespace.If you think about this, you'll realize that White A (38 in the game) and White 1 are both the same sort of move. The purpose of both of them is to occupy the key point for the eyespace of point weak groups.In contrast, after White 1, Black's weak group starts to resemble a 'stick'. This sort of one-dimensional group doesn't have much eye potential and often finds itself under attack. The connection between B and C becomes thin and White can aim to cut with D later on.];B[gd];W[fd];B[fe];W[he];B[ge];W[hb];B[je]LB[hb:7][fd:3][gd:2][fe:4][ge:6][he:5][je:8][df:B][gf:C][ch:A][eh:1]C[Black 2 is a good move which presses White down while also dealing with the thinness between Black B and Black C. The continuation up to Black 8 can be expected. Continuing...];W[er];B[dr];W[fq];B[ep];W[hp]LB[ep:4][hp:5][fq:3][dr:2][er:1]TR[jp][lq]SQ[ch][eh][cj][ej]C[If White now puts things in motion in the lower left corner, as he did in the game, we can see that the game is much easier for White to play.White's marked stones are strong, so Black only has one weak group to aim at. The fight between Black's bottom group (marked) and White's lower left group becomes more balanced.Try to remember that depth creates eyespace when playing in the center and eyespace creates power.I think this variation would have been better White than the result in the actual game.]))(;W[ff];B[di];W[dj];B[fg](;W[gg];B[fh]LB[ff:38][fg:41][gg:42][fh:43][di:39][dj:40]TR[cj][ej]C[White could also consider attacking from above with White 38. Sealing a weak group in and forcing it to live locally is another strategy, which is usually good. However, in this case Black will resist with Black 39 through to Black 43.White's marked group on the left side is heavy and finds itself in quite a bit of trouble. If the surrounding position isn't strong enough to contain a group, insisting on sealing it in anyway often backfires.])(;W[eg];B[ef];W[eh];B[ed];W[ec];B[cc];W[dc];B[be](;W[cd];B[bg]LB[bc:A][cc:6][dc:7][ec:5][cd:9][ed:4][be:8][ef:2][bg:10][eg:1][eh:3][ei:B]C[You might wonder whether White can resist with White 1 and White 3. However, Black can fight back with Black 4, Black 6 and Black 8. Black 10 is a tesuji which makes miai of A and B, which are both strong continuations for Black. Continuing...];W[ch];B[fe];W[gf];B[ge];W[hf];B[he];W[if];B[bc];W[bd];B[ad];W[hc];B[ie]LB[bc:8][hc:11][ad:10][bd:9][fe:2][ge:4][he:6][ie:12][gf:3][hf:5][if:7][ch:1][fh:C][ei:A][fi:B]C[White should defend with White 1, because Black's push and cut with A-C will be severe if he plays elsewhere. Next Black pokes his head into the center up to Black 6 and then takes the eyespace in the corner with Black 8. Up to Black 12, it's hard to tell who's attacking whom.])(;W[bd];B[cd];W[de];B[bg];W[ae];B[bf];W[bc];B[ei];W[fi];B[fh]LB[bc:7][bd:1][cd:2][ae:5][de:3][bf:6][bg:4][fh:10][ei:8][fi:9]TR[eg][eh]C[White could also play White 1, instead of 2, but it doesn't greatly alter Black's tactics. Black 4 is still a nice tesuji, which makes miai of 7 and 8.The sequence up to Black 10 is powerful. Even though Black's cutting stones seem to be very short of liberties, you'll find that White can't capture them. It's worth noting again the important role that Black 4 plays in making Black 8 and Black 10 possible.];W[dh];B[ci];W[ch];B[bi];W[bh];B[ah];W[bj];B[ai];W[ag];B[af];W[aj];B[ag];W[ee];B[ad]LB[bg:A]C[White can start a capturing race like this, but Black wins the race by one liberty. This variation clearly illustrates the key role of Black A.]))))(;W[dc];B[cf];W[ef]LB[dc:1][cf:2][df:A][ef:3]C[White could also consider playing White 1 (or A) to secure the left side more firmly. If Black invades at Black 2, White can cap with White 3 and attack Black.]))(;B[dr];W[er];B[fr];W[ep];B[fq];W[cr](;B[dp];W[cq]LB[bp:A][dp:7][ep:4][cq:8][fq:5][cr:6][dr:1][er:2][fr:3][ds:B]C[If Black wants to resist, he'll hane underneath with Black 1. White's crosscut at White 2 is a useful sabaki tesuji which comes up fairly regularly in games. Black can seal White into the corner through to White 8, but White can live (in ko), because A and B are miai.])(;B[es];W[cq];B[co];W[dp];B[go];W[dn];B[cm];W[fn]LB[bm:B][cm:7][cn:A][dn:6][en:C][fn:8][co:3][go:5][dp:4][fp:D][cq:2][es:1]TR[gl][il]C[If Black wants to capture all of White's stones, he doesn't have time to cut at 4, and should take White's single stone with Black 1 instead. This is an aggressive strategy.White can move out with White 2 through to White 8 and Black's surrounding stones aren't strong enough to capture White's group.There's some bad aji in Black's position around A, and White will either escape into the center or make two eyes. Playing Black 7 at A or B is also conceivable, but it doesn't help to remove White's aji. If Black attacks from the other side, with Black 5 at C, White will push at D and Black still can't capture White.However, the situation might change is Black has expanded his moyo later on in the game. For example, if Black had already played stones on the marked points (triangle), Black would be able to play like this to capture White's whole group. That's why the timing of White's probe was very important.Developing a sense for the timing of probes like this will help you to become a stronger player.])))(;W[cm];B[nr];W[om];B[pk]LB[pk:5][cm:2][om:4][jp:1][nr:3]C[If White ignores Black 1 and takes the big point at White 2, sliding to Black 3 will set White's lower right group adrift. Black will be happy to take territory on the right and at the bottom while attacking White.]))(;B[lp];W[mq];B[lo];W[cm]LB[cm:4][lo:3][lp:1][lq:A][mq:2]C[Pushing up with Black 1 is the most common response to a shoulder hit against a stone on the third line. However, this variation is a transposition of the diagram we saw earlier (where Black pincered at 1 instead of A). As we know already, this result is good for White.])(;B[mq];W[nq];B[lp];W[mo];B[hp];W[cm]LB[cm:6][mo:4][hp:5][lp:3][mq:1][nq:2]C[Pushing with Black 1 is also conceivable. After exchanging Black 1 and Black 3, Black will want to defend his three stones with Black 5. Otherwise, White will pincer them. However, White still has time to take the big point at White 6 in that case, so the result is ok for him too.])(;B[nr];W[lp];B[kq];W[ip]LB[ip:4][lp:2][kq:3][nr:1]C[Taking away White's base with Black 1 is conceivable too, but White can fight back with White 2 and White 4. Black's three stones feel a little heavy.If Gu had felt that this fight would be alright for Black, he might have played like this, because it fits well with his style. However, the move he played in the game was better.]))(;W[mo]LB[mo:1][ro:B][kp:A]C[White could also think about this knight's move at White 1, which makes miai of A and B. This technique requires the potential ladder to favor White.](;B[ro];W[kp];B[jq]LB[mo:1][ro:2][kp:3][jq:4]C[If Black defends his corner with Black 2, White will be able to reduce Black's potential at the bottom, while developing influence in the center. This is another game, but White's group is still floating in the center and it seems like Lee didn't like that prospect.])(;B[jp];W[ro];B[rp];W[qo];B[po];W[pp](;B[so];W[pn];B[rn];W[oo]LB[pn:9][rn:10][mo:1][oo:11][po:6][qo:5][ro:3][so:8][jp:2][pp:7][rp:4]C[If Black defends the bottom with Black 2, White will harass Black's corner.Because the ladder favors White, White can capture Black 6 while Black connects along the first line. White's group becomes strong and solid and Black's corner territory is greatly reduced.])(;B[qn];W[so];B[oo];W[rr]LB[pn:A][qn:1][oo:3][so:2][rr:4]C[You might think that Black 8 (2 in this diagram) in the previous variation looked strange. However, if Black plays at Black 1 instead (which looks normal), descending with White 2 is a powerful tesuji, which makes miai of A and White 4. Black doesn't have a good continuation after White 2, so his position collapses.]))))(;B[lp];W[rr];B[rp];W[mq];B[lq];W[mp];B[lo];W[cm]LB[cl:A][cm:8][lo:7][lp:1][mp:6][rp:3][lq:5][mq:4][rr:2]C[Pincering on the fourth line with Black 1 is more common in this kind of position. White will respond with White 2 through to White 6. However, Black will feel compelled to extend at Black 7. That's because White's 'hane at the head of two stones' at 7 would be too painful to endure.As a result, White will have sente to extend to White 8, which prevents Black A and greatly reduces Black's potential in the lower left. White will be happy with this result.])(;B[mq];W[mp]LB[mp:2][mq:1]C[If Black pincers more tightly at Black 1, it will become easier for White to counter-attack and manage his group flexibly. Attaching with White 2 seems like a good way for White to continue in this opening and though there are so many possible continuations that a whole book could be written about it. So that we have time to get back to the game, let's just look at one possible continuation...];B[lp];W[ro];B[rp];W[qo];B[po];W[pp];B[qn];W[pn];B[oo];W[nn];B[so];W[no];B[rn];W[lq];B[nq];W[kp];B[lo];W[kr];B[lr];W[kq];B[np];W[qo];B[ro];W[on];B[qo];W[ln];B[or];W[mr];B[nr];W[ls];B[qr];W[cn]LB[cn:C][ko:B][mo:A]C[This particular variation is one that Lee's played in several other games and it works well with the rest of the board in this opening.White develops influence and takes sente, while Black takes territory in exchange. A and B are miai, so White can take a big point with C. White would be satisfied with this result.]))(;B[nc];W[rd];B[qc];W[qi];B[ro];W[kq]LB[nc:1][qc:3][rd:2][qi:4][ro:5][kq:6]C[Defending the corner with the knight's move would be the most basic response to White's approach move. However, the result up to White 6 would be quite satisfactory for White, because Black is forced to reinforce with Black 5.Black 5 gives White the impetus to extend to White 6. In addition to creating a base for White's lower right group, White 6 reduces Black's potential in the lower left, so Black didn't like this variation.]))(;W[kq];B[fc];W[df];B[jd]LB[fc:2][jd:4][df:3][kq:1]TR[cp][eq]C[Extending at the bottom, with White 1, would be gote. Black's lower left corner is already safe. Black can develop a framework at the top with Black 2 to Black 4. The opening still looks favorable for Black.])(;W[rr];B[qj]LB[pd:A][qj:5][qm:3][ro:B][pq:2][rq:1][rr:4]C[Continuing to exchange moves in the lower right is unnecessary right now. If White continues with White 4, Black will develop rapidly with Black 5. Because Black 5 is fast, and also works well to develop a framework with Black's top right star point at A, the exchange of White 4 for Black 5 is regarded as being good for Black.This is a good example of one difference between modern and classical opening theory. It used to be normal for Black to make shape with Black 3 at B. That move is stronger with regards to the corner territory, but slower with regards to the whole board and the opening. Black 3 and 5 represent a larger scale view of the opening.After White 4 and Black 5, White has a nice tesuji at B, but it's too slow to play here now, because White's lower right group is already strong. If White plays at B now, Black will tenuki and take another big point.]))(;W[pp];B[qo];W[rq]LB[qk:C][qo:2][pp:1][rp:A][kq:B][rq:3]C[Continuing in the lower right corner would be better. White 1 or A are the normal ways to continue here. After White 3, B and C can be regarded as miai for White and the opening is still even.]))(;W[cp];B[do];W[co];B[dn];W[cm];B[mq]LB[cm:5][dn:4][co:3][do:2][cp:1][op:A][mq:6]C[In the event that White approaches the lower left corner with White 1, Black already has a plan. Black's wall in the lower left will provide support for Black's pincer attack against White A, at Black 6.]))(;B[oq]C[Attaching underneath, to secure the corner territory, is also playable.];W[nq];B[pq](;W[np];B[qn](;W[dp];B[jp];W[hq]LB[qn:5][dp:6][jp:7][np:4][hq:8][nq:2][oq:1][pq:3]C[Connecting solidly at White 4 is a normal move which is often good. Even though White hasn't made a base for his lower right group yet, taking the corner with White 6 is very big.If Black pincers White's lower right group with Black 7, White can counter-pincer at White 8. Since both players now have one unsettled group, a running battle in the center can be expected and neither player is at a particular disadvantage. This would be another game.])(;W[jq];B[co]LB[qn:5][co:7][dp:B][np:4][dq:A][jq:6][nq:2][oq:1][pq:3]C[White 6 follows a basic Go proverb, "extend three spaces from a two stone wall."White can make a base for his stones at the bottom and complete a joseki with White 6. However, Black will then take the last open corner with Black 7. Black's played first in three corners, so it's hard to deny that White's opening is slow.Black 7 could also be at A or B if Black prefers.]))(;W[mp];B[fq];W[cp];B[no];W[np];B[qn];W[iq];B[cq]LB[qn:9][no:7][cp:6][mp:4][np:8][cq:11][eq:A][fq:5][iq:10][nq:2][oq:1][pq:3]C[The opening up to here is the same as the second game of the 16th China Korea Tengen title match, between Choi Cheolhan 9p and Chen Yaoye 9p. Choi played White 4 in that game and the progression through to Black 11 followed.Black 5 was a strategic and flexible move (A is also possible). After White 6, making a two space extension to 10 and attaching at Black 11 were miai for Black. This opening is playable for both players.])))