The Ten-Game Match, Game One
                        Gu Li vs. Lee Sedol

Go fans from around the world have long awaited this showdown between the top two go
players in the world, Gu Li and Lee Sedol (transliterated as Yi Se-tol in other publications),
who are battling for a $820,000 prize, the richest in go history. The first game was played
in Beijing, on January 26, 2014. In attendance was the legendary Chinese player Nie Wei
Ping 9-dan, who was the nemesis of the top Japanese players during the heyday of
Japanese go. His presence was most likely to provide encouragement and inspiration to
Gu, his former disciple. In Lee's corner was his wife and daughter, who traveled from
Canada, where his daughter is studying, to cheer him on.

                  Why a Ten-Game Match?

I mentioned to a friend that one of the most exciting go matches in the last 70 years was
being played to determine the world's strongest go player. I also mentioned that it was
a 10-game match, to which he immediately replied that that was the stupidest thing he
had ever heard: 'Don't you guys realize there is a chance that it could turn out to be a
5–5 tie?' I was so taken aback at his reaction that I couldn't come up with a good answer.
I lamely retorted that it was a traditional Japanese thing. He said that this lack of rationality
was so typical of Japan. They prefer tradition to an actual solution. (I should add that my
friend is Japanese, but he grew up in the USA.) I said that it was actually organized by a
Chinese sponsor and that the two players were a Chinese and a Korean. He just shrugged
his shoulders in disgust. I tried to give him a rational explanation by explaining that a
best-of-nine or -eleven match would give an arbitrary result, especially because the
winning ratio with Black and White is only slightly different. Moreover, the possibility of a tie
would save face for equally strong opponents. He thought that this was nonsense. All
he wanted was a winner.

Thinking about this on the way home, all the good arguments I had and what I should
have said came to mind.

The purpose of a match is to determine who the stronger player is. If they are of equal
strength and they fight to a tie, so be it. If a winner is needed to crown a holder of a title,
then a best-of-three, -five, or -seven match is more appropriate, and there are a lot of
those matches already.

In chess, world championship matches have always had an even number of games. In the
1950s, 60s, and 70s, the matches consisted of 24 games. Two matches ended in ties, but
the majority usually produced a clear winner. The most recent world-chess-championship
match was a 12-game affair. The problem with chess is that many games end in draws,
so the chances of the match ending in a tie are greatly increased. Therefore, if matches
with an even number of games have been successful for chess, they should be even
more appropriate for go matches, where draws are rare.

Throughout the history of go in the Edo period (1603–1868), all matches ever held have
consisted of an even number of games. There have been six-game, ten-game, 20-game,
30-game and even 60-game matches. Except for two, these matches were never finished,
but most produced clear winners. The only exception was a six-game match, which ended
in a tie (Black won each game). This is also what happened in the first Honinbo title match
played in 1941. That match consisted of six games as well and it ended in a 3–3 tie with
Black winning every game. The conclusion we might draw from this is that the players
were of equal strength, or six games is not enough to produce a clear-cut winner. In the
1940s and 50s, Go Seigen played a number of ten-game matches with the top players
of that era, winning them all. (A history of go in the Edo period can be found in
The Go Players Almanac. Details of the first Honinbo tournament and title match
can be found in Modern Master Games.)

In both chess and go, the player with the first move has the advantage. Go has a way
to compensate for White's disadvantage — the komi system, but up until the late
1930s there was no komi in official games. Players of equal strength would alternate
between playing Black and White, but having the first move was a great advantage. A
player such as Shusaku was almost invincible when playing with Black.

In match play, the no-komi system worked out well. It proved that the player who could
overcome the disadvantage of not having the first move was the stronger and the player
he vanquished would have to accept a handicap.

The advent of the tournament system made equality among the competitors imperative.
In the first Honinbo tournament a komi of 4½ points was introduced, but it was used
only in the preliminary rounds. The six-game title match was played without a komi.

White: Gu Li 9-dan (China)
Black: Lee Sedol 9-dan (Korea)
Komi: 6.5 points; time: 4 hours each plus 60 seconds per move overtime.
Played on January 26, 2014 in Beijing, China
Commentary by Rob van Zeijst, three-time European champion and former Japan Go
Association insei (apprentice professional), compiled from various commentaries of top
Chinese, Korean and Japanese professionals.
Click to download SGF file for this game.

                         Figure 1 (1–7)

Figure 1 (1–7)
Lee started out with Black 7, the latest version of the mini-Chinese opening. Black 7 at A is the usual move associated with this opening, but Black 7 in the game is closer to the stone at 3, so the corner is more tightly defended.

                         Dia. 1

Black 1 to 8 show how the mini-Chinese opening was played in the early stages of its development. There were many games in which Black 3 was played at 'a'.

                         Dia. 2

Before White 4 in Dia. 1 became the standard move, a number of games were played in which White played the knight's move of 4. However, because Black could secure a large territory with 5 to 13, this move was deemed unsatisfactory.

                         Dia. 3

Instead of 5 in Dia. 1, Black 5 to White 12 in Dia. 3 is a variation that is very popular these days. After 12, Black can strengthen his moyo with a move around 'a'. Instead of 10, however, White can cut at 'b' and start a violent fight with hair-raising variations. To better deal with this cut, Black 'c' has been gaining popularity.

                         Dia. 4

Instead of 6 in Dia. 3, players have been experimenting with the variation in which White attaches at 6 before pushing up with 8 and extending to 10. This is a roughly even result.

                         Figure 2 (8–10)

Figure 2 (8–10)
Typical of his aggressive style, Gu plays 8 and 10. White 8 is meant to make Black's stone heavy before attacking with 10.

                         Dia. 5

White 1 is the normal move to deal with the mini-Chinese opening. The sequence to Black 6 is natural. Although the cut of White 7 and 9 is worrisome, Black can deal with it by playing 10 to 14. Black's marked stone is now in a better position to capture the stones at 9 and 13 than it if were at 'a'.

                         Dia. 6

An alternative to White 8 and 10 in Figure 2 and White 1 in Dia. 5 is for White to first stake out a position at the top with 1 and 3. Black can then play a splitting move with 4 to establish a position on the left side. Instead of 4, Black 'a' and 'b' are also possible.

                         Figure 3 (11–16)

Figure 3 (11–16)
Black 11 probably took Gu by surprise. He was looking for a fight at the bottom, but Lee was ignoring him. However, from Black's perspective, this is the ultimate expression of kiai, an important concept covered in Kiseido's best-selling book Fight Like a Pro — The Secrets of Kiai.

In general, forcing the exchange of 14 for 15 before playing at 16, looks a bit like an overplay. However, since White wants to play 16 anyway, he could interpret the exchange of 14 for 15 as an 'inducing move' — an exchange that makes White 16 more natural. This is sometimes called the 'natural flow' and inducing this type of flow generally implies great efficiency. So there are two sides to this story. However, on a practical level, White has one more argument up his sleeve (see Dia. 11).

                         Dia. 7

Instead of 11 in Figure 3, Black can easily save his stones by running away with 1 to 7. However, White would then probably play at 'a' and the next fight would start. There is no reason for Black to shy away from this variation, except that it would mean Lee playing the moves that Gu wants him to play. This is the antithesis of kiai.

                         Dia. 8

If White plays 1 after Black 11 in Figure 3, Black can easily avoid a direct confrontation with 2, which forges a loose link-up at the bottom. Later, Black can fight with 'a'–White 'b'–Black 'c'.

                         Dia. 9

White could stop Black from linking up underneath with 1, but that would provide Black with the perfect opportunity to escape with 2 and 4. If the sequence to 8 follows, it is true that a white move at 'a' would be slightly more severe than without his stone at 1 in Dia. 7. However, White's move at 1 in this diagram is slack and spending an entire move on this point is not justified.

                         Dia. 10

If White reverses the order of 14 and 16 in Figure 3 and exchanges the shoulder hit of 1 in Dia. 10 for Black 2, after White 3, Black might not jump to 4. Instead, he could form a nearly unbreakable link by playing at 'a' or defend the right side with 'b'.

                         Figure 4 (17–20)

Figure 4 (17–20)
Black 17 is a calm and composed move, showing that Black is fully aware of White's intentions, thwarting problems before they show up.

White 18 blocks an escape route for Black's two stones at the bottom while providing some support to his marked stone.

Now is the time for Black to attach at 19 and escape with his two stones on the bottom left.

                         Dia. 11

Instead of 17, if Black tries to link up underneath with 1, White can force the exchange of 2 for 3, then cut off the two black stones with 4 to 8, securing a large territory on the bottom left with 10. However, before doing so, White would play at 'a' to see how the situation on the right would turn out. When the time is right, he would then play the sequence shown here.

                         Dia. 12

Instead of 19 in Figure 4, invading the corner with Black 1, followed by the hane of 3, are a common technique to make sabaki in this kind of a position. However, this would help White reinforce his stones with 2 and 4. If Black now attaches with 5, White can cut off the black stones below with 6. This would be a disaster for Black.

                         Dia. 13

After Black attaches with 19 in Figure 4, if White crudely cuts with 1 and 3, Black cuts with 4 and 6. White has no choice but to connect with 7, so Black can play 8, greatly weakening White's marked stone. This would be a disaster for White.

                         Figure 5 (21–27)

Figure 5 (21–27)
After Black pushes up with 21, White keeps up the attack on the outside with 22, threatening to cut off Black's two stones below, so Black links up with 23 and 25.

After White defends with 26, Black gets out into the center with 27.

                         Dia. 14

Instead of 22, White might cut with 1. After Black cuts with 6, he gets a lot of forcing moves with 10 to 20, but White won't collapse. Finally, Black defends with 22. Not only is Black's influence greater than White's profit, White still has to worry about the aji of Black 'a'.

                         Dia. 15

Instead of 23 in Figure 5, extending to Black 1 is a mistake because White can cut Black off with 2 and 4. After the sequence to 8, Black's stones on the bottom left are doomed because White can escape with 'a' or 'b'.

                         Figure 6 (28–37)

Figure 6 (28–37)
With 28, White tries to score some points in the corner hoping to force Black to defend in such a way that it becomes more natural for White to make a defensive move in the center. Again, this looks like the natural flow.

Up to here, the professional concensus was that White was doing a little better, but Lee played a brilliant tesuji that upset this flow (Black 39 in Figure 7).

White 30 was too tight. This move should have been played at A.

With 31, Black initiates a sequence that gives him a very small advantage, eventually providing that little extra, which becomes apparent some 150 moves later.

White 34 is the only move.

                         Dia. 16

Instead of 29 in Figure 6, if Black blocks with 1, he can expect the result to 12. That is where the skirmish stops because Black A is not sente, and that is a very important difference from the result in the game. As a matter of fact, Black A in the game became sente and that gave Black a few extra points in the endgame. A characteristic of the top players is that they fight for every point — that is what sets the title holders apart from the pack.

                         Dia. 17

Instead of White 30 in Figure 6, White 1 here provides a little more speed. It looks more flimsy than 'a', but, even if Black peeps at 2, White 3 makes a strong, yet resilient shape.

                         Dia. 18

After White 1, Black would probably play in the corner with 2 to 10, as in the game. He would then force with 12 to 20. White has to connect with 21, so Black can make two eyes for his group with 'a'–White 'b'–Black 'c'.

                         Dia. 19

Answering Black 29 in Figure 6 with the extension of White 1 is a mistake. After Black 2, White has no way to defend the center.

                         Dia. 20

In Figure 6, we wrote that White 34 was the only move. But White looks quite strong above and vulnerable in the corner. So why can't White block with 1 in Dia. 20?

If White blocks at 1, Black will exchange 2 for 3. Later, when the time is ripe, Black 4 becomes a big move. But is it absolute sente? Suppose White ignores it and switches to the top right with an approach at 5. Black continues by forcing with 6 and 8.

Question: Can Black link up his two stones at 6 and 8 to the one at 4?

                         Dia. 21

The diagonal move of Black 1 is the first move that comes to mind. It's the famous 'monkey jump' tesuji from the marked stone. It is usually quite reliable in securing link-ups, but in this case it fails. White starts with the diagonal move of 2, then throws in a stone with 4. After Black captures with 5 —

                         Dia. 22

White blocks with 6 and Black cuts with 7. Next, White ataries with 8 and Black captures with 9. White now ataries two stones with 10. Black can't connect at 'a' because he is short of liberties; that is, if he connects at 'a', he is still in atari, so White can capture the three marked stones. Therefore, the diagonal move of Black 1 in Dia. 21 fails.

                         Dia. 23

Black 1 should jump to 1. Black 3 looks natural, but it is wrong. White 2 to 6 set up a ko. Black makes a ko threat with 8 then retakes the ko with 10. Of course, this ko would still be good for Black and it would be enough of a threat to make Black's marked stone sente. However, to link up without having to fight a ko would be best for Black. Is that possible? Think about this before going on.

                         Dia. 24

Black's best moves
After White wedges in with 2, descending to Black 3 is the tesuji. After the sequence to 9, all of Black's stones are linked up. Note that if White plays 4 at 7, Black should just block at 5.

                         Dia. 25

From our analysis in Dias. 21 to 24, it would be quite dangerous for White to ignore Black 4 in Dia. 20. Therefore, he answers that move with 5 in this diagram. Black now plays a series of forcing moves with 6 to 10, then confines White to the lower right side with 12. Next —

                         Dia. 26

White tries to break out with the moves from 13 to 19. He fails, but, when he plays 21, he has trapped the eyeless black group on the bottom left with 21. Fortunately, Black has a nice atekomi tesuji with 22 that forces White to connect at 23. He then plays 24, capturing the eight white stones on the lower left side. Therefore —

                         Dia. 27

White has no choice but to secure his group on the lower left side with 21, allowing Black to move out into the center with 22 and giving him a big advantage — he is thick in the center and the marked stones are under attack.

Both Gu and Lee must have read out the long sequences from Dias. 20 to 27 with all their respective tesujis and concluded that White 34 was the correct response to Black 33. Such impressive reading (or analytical) ability comes from years of solving life-and-death problems as well as developing an intuition that enables them to instantly spot a tesuji and to determine whether or not that tesuji works. The only way to develop this power of analysis and intuition is to study life-and-death and tesuji problems. Click here to see a list of the problem books published by Kiseido.

                         Figure 7 (38–42)

Figure 7 (38–42)
White plays a hane with 38. Why couldn't White have extended to 41 instead? Answer and analysis is given in Dias. 28 to 36.

Black 39 is the follow-up tesuji to White 28 in Figure 6.

White 40 and 42 may seem like a strange answer to Black 39, but these moves make sure that Black has a sente move only at A and not at B. By making sure that A is sente, Black has also made sure that he can make an eye in sente with C, just in case he ever needs to.

                         Dia. 28

Instead of the hane of White 38 in Figure 7, White must not extend to 1. Blocking with Black 2 is also a mistake. White cuts with 3 and 5. Black 6 to 12 are a smart way of taking away White's liberties, but, after 14, White 15 and 17 make a seki in the corner. However, Black's four stones around 2 will be captured, breaking the seki, so, in the end, all of Black's stones in the corner will also be captured. Incidentally, White 17 is the professional move to take away Black's liberties. It is better than playing at 'a'. Next —

                         Dia. 29

If Black now plays 18, even if White answers with 19, Black cannot break the seki in the corner. It now becomes apparent that White's stone is better placed at 19 than at 21.

With the seki in the corner in place, White can capture the four black stones at the bottom at his leisure because linking up with Black 22 does't work, as Black's stones are now short of liberties.

Note that White should not answer the hane of 14 in Dia. 28 by playing at 26 in this diagram. Black would connect at 20 and, after White 27, capture six white stones in the corner with 'a'.

                         Dia. 30

Black 6 is an interesting tesuji that makes miai of linking up at 'a' and capturing the corner. If White plays at 7 to prevent Black from linking up at 'a', Black cuts with 8 and squeezes with 12 and 14. Black wins the capturing race when he ataries with 16.

                         Dia. 31

When Black descends to 6, White should defend the corner with 7 and let Black link up his three stones at the bottom with 8 and 10. White now takes aim at Black's group in the center and attacks it with 11 and 13. Black's center group would be captured and he would be forced to resign.

Conclusion: Black cannot answer White 1 in Dia. 28 by blocking with 2.

                         Dia. 32

The correct move:
After White 1, Black 2 is the correct response. Black 4 is sente, so White must extend to 5. But Black 6 is a good move that weakens White's center considerably. If White tries to save his stone with 7, Black squeezes with 8 to 14, then takes the initiative in the center with 16. White's marked stone is almost dead, so this is a great success for Black.

                         Dia. 33

After White 6 in Dia. 32, White might atari with 7, but, after Black 8 and 10, White's marked stones are almost dead. This is also a terrible result for White.

In conclusion, extending to White 1 in Dia. 32 leads to a bad result if Black answers with 2. The only question that remains is — Does White's group on the bottom left in Dia. 32 have any bad aji that Black can exploit?

                         Dia. 34

Black 1 is the only move worthy of consideration. Without this move, there is absolutely no aji in the corner. White cannot answer with 2 because Black 3 and 5 are an exquisite tesuji combination. If White answers by turning with 4, Black 7 forces a ko. Instead of 4, if Black connects at 5, Black kills the white stones with an atari at 4. Alternatively, if White plays 4 at 6, Black starts a ko with 7.

In conclusion, descending to White 2 leads to the collapse of White's group.

                         Dia. 35

White has no choice but to play 2 and 4. After Black 5, how does the capturing race play out?

                         Dia. 36

White 6 and 8 are the correct combination. This leads to a double ko. There are a number of ways to set up this double ko, the sequence here being the representative one. However, Black 12 will certainly be sente, which almost certainly kills White's marked stone. In addition, even if it is a double ko, that means, Black would have an infinite source of ko threats. Locally, Black would lose, but globally, White is at a disadvantage because he can no longer afford to get involved in any ko fights.

                         Figure 8 (43–45)

Figure 8 (43–45)
Black 43 and White 44 are natural moves. The game looks even.

Black 45 was a great move that aims at a cut around A or B. If White defends against this cut, that will be Black's cue to defend against White C. We will see how this unfolds in the game.

                         Dia. 37

It may seem that White's stones in the corner are vulnerable. Black 1 to 5 are sente, but, if Black threatens to start a ko with 7, White extends to 8 and Black has no follow-up move.

                         Dia. 38

Instead of Black 45 in Figure 8, Black 1 makes the wrong shape. Later, White can attach at 2 and there is no easy way for Black to deal with this because White can peep at 4. After 8, Black's position is full of holes and thin.

                         Dia. 39

Black 1 is also problematic, because there is still the problem of the wedge-in at 'c' when White plays a move around 2. Black cannot ignore White 2 because White will play the sequence from 'a' to 'g', trapping the black stones. Black will most likely die.

                         Dia. 40

Actually, White would not play at 2 in Dia. 39, but might first try to pull out his marked stone by attaching with 2 and peeping with 4. White would then attack the three black stones by capping with 6, leading to a fight in the center. Black now has a problem.

By playing 45 in Figure 8, Black defends against this threat.

                         Figure 9 (46–52)

Figure 9 (46–52)
White 46 creates aji in the corner. Later, a two-step hane at 'a' will create additional aji, through which White can somehow live in the corner, depending on the surrounding stones.

White 48 is a strong response to Black 45 in Figure 8. Neither Black nor White is giving in and each is always resisting his opponent's plans — the style of both players embody the spirit of kiai.

At the moment, it is difficult to evaluate whether the exchange of 48 and 50 for Black 49 and 51 is good or bad for White. The white stones on the bottom right have become markedly weaker, but White's group in the center has become slightly stronger — or has it?

White 52 was widely criticized because it ignored the problem in the center. This problem was immediately exposed because White 52 was not answered until over 100 moves later. White 52 was not an urgent move and it immediately changed the flow of the game.

                         Dia. 41

Locally, Black can resist White 48 in Figure 9 with 1 and 3. The moves to Black 9 will probably follow, but White is now strong in the center, so he can resume his attack on Black's center group with 10. White will answer by running away with 11. Because of the marked stone (Black 45 in Figure 7), the wedge in at 'a' doesnt work. Later, White can probably make life in the corner with 'b'.

                         Dia. 41a

Instead of 49 in Figure 9, Black can't resist with 1. After White 2, he has no follow-up. If he tries to cut with 3 and 5, White simply cuts with 8 and 10.

                         Figure 10 (53–60)

Figure 10 (53–60)
Black 53 is the key point. It is a direct threat to cut through White's center position. (See Dia. 42.)

White 54 takes away a potential eye for Black.

With 58, White could have extracted better use of the marked exchange than he did in the game (see Dia. 45). As it turned out White 58 was 'too honest' and contributed to White's shape falling apart and Black being able to take the initiative.

Black 59 is the honest or proper move. If Black were to jump to A, White would extend to B and Black would have to reinforce with C.

White 60 was also criticized for being irrelevant. It was probably meant as a probe, as Black can answer in two ways, at D or E. Depending on Black's answer, White would modify his strategy.

                         Dia. 42

With the marked stone (Black 53 in Figure 10) in place, Black can attach with 1 and cut off White's group with the sequence to 7. Black's group also gets cut off from the center, but he can live with the sequence to 21. However, the marked stone is on the key point of this shape, so White's group is extremely weak and may well die.

                         Dia. 43

White might play 1 and 3, then brutally cut through with 5 and 7, but Black captures four stones in a ladder with 8. If White can't get adequate compensation, this will be an unacceptable loss. Therefore —

                         Dia. 44

White goes after the black group with the attachment of 9. Next, Black plays 10 to force White to atari at 11 so that Black can capture four stones with 12. White wants to kill Black, so he needs to take away Black's eye with 13. He then reinforces with 15, but Black can still play 16 to 26 to secure two eyes.

                         Dia. 45

Although it looks counter-intuitive, White could have attached with 1 to force Black 2, then played a hane with 3. This would be an indirect defense that results in a more efficient shape than in the game.

                         Figure 11 (61–67)

Figure 11 (61–67)
Even though the lower right corner is worth at least 30 points, Black starts hunting for bigger prey. If he can cut off the two marked stones, it will be much bigger than the lower right corner, which is big, but not urgent.

At any rate, capturing White's marked stones would be big because they make Black's weak group on the left strong. In general, a weak group is worth minus 20 points, so capturing these two stones would be worth about 20 points for making the group strong plus almost 20 points of actual territory — 40 points altogether.

Of course, White resists with 62.

White 64: Allowing Black to play at 64 would be unbearable.

White 66 is a smart move that forces Black to end in gote if he is intent on keeping up the attack.

After the previous explanations, it is clear that 67 is the only move.

                         Dia. 46

Instead of 61 in Figure 11, Black can atari at 1 and let White live in gote with 2 to 6. However, White will probably not play 4 and 6 just yet because it is only worth about 20 points in gote — too small at this stage — so Black would be taking a risk to go after the corner.

                         Dia. 47

If Black has a stone around 'a', he might try connecting with 3 and try kill White with the diagonal move of 5. If White ataries with 6, Black will extend to 7, leaving White with a false eye at 1. However, unless there is a stone around 'a', it is unlikely that Black can kill White unconditionally.

                         Dia. 48

The ataries of Black 1 an 3 are another possibility. Depending on the position, White can stop at 4 and jump to 'a' or he can play the sequence to 8. It all depends on the surroundings. However, it is smart for White to make Black commit himself before deciding on his own strategy.

                         Dia. 49

Instead of 64 in Figure 11, White can connect his stones to the outside with 1 to 5. However, Black takes the initiative with 8 and 10. In the worst case, Black can always capture two stones with 'a' to 'e', but more importantly, after Black 10, even if White manages to escape to the right side, Black will probably become stronger around 'f'. As discussed in Dias. 47 and 48, that means that Black may be able to kill White's three stones in the lower right, and that would be a terrible outcome for White.

Incidentally, instead of 4, Black cannot cut at 5, because his stones will be captured after White pushes in at 'g'.

                         Dia. 50

Instead of White 66 in Figure 11, if White connects with 1, Black can take sente and switch to the lower right corner. In the sequence to 8, White's two marked stones are still capture and Black gets a lot of territory at the bottom in sente after White captures with 11.

                         Dia. 51

Instead of 67 in Figure 11, Black 1 would be a terrible mistake. White gets to defend against a cut with 2 in sente before switching to the lower right corner with 4. White is now ahead.

                         Dia. 52

Even now, Black can still compromise by connecting with 1, leaving open the option of cutting at 'a'. However, this gives White the opportunity to exchange 2 for 3 later, leading to an unconditional loss of two points from the ideal. In addition, instead of playing at 2, depending on how the position develops, White can still play at 3, threatening to cut with 'b'–Black 'c'–White 'd'.

                         Figure 12 (68–75)

Figure 12 (68–75)
With 70, White has managed to rescue two stones but at the expense his center group that becomes a target of Lee Sedol's attack.

Black 71 takes away White's eye space and strenghtens his own stones.

Instead of defending the center, which is natural, White lays waste to the bottom with 72 while trying to make eyes.

Black 73 is a big, safety-first move.

White more or less secures his group with 74.

With 75, Black secures the corner and threatens to rescue his stone with A — this move will prove to be the winning move more than 100 moves later.

                         Dia. 53

Instead of 72 in Figure 12, if White first pushes up with 1, Black builds strength in the center with 2 and 4. After this, he is better able to resist White's cut at 9 and 11. Black 14 and 16 are forcing moves that enable Black to link up with 18 and 20. After Black 22, White's position on the bottom right collapses.

                         Dia. 54

Instead of 73, it's hard to understand why Black didn't block at 1 and play the sequence to 11 to link up his stones at the bottom. Compared to the Dia. 53, White has sente moves around 'a', so Black must have been worried that his marked stones could get into trouble. However, if White now plays 'b', Black can escape with 'c'. This could have been the chance for Black to quickly decide the game.

                         Dia. 55

Instead of 73, Black 1 is a mistake. White can play 2 later on to escape with his main group. In other words, Black needs two moves to capture White's seven marked stones that are worth about 20 points, making each move worth 10 points, hardly big enough at this stage of the game.

                         Dia. 56

Black can't capture White's center group by cutting at 1. White would strike back with 2 to 8 and captures the four key cutting stones in the center.

                         Dia. 57

However, compared to Dia. 54, the exchange of the marked stone for 1 reinforces Black on the outside. In this case, it is very likely that White will collapse.

                         Figure 13 (76–89)

Figure 13 (76–89)
After having made the forcing moves of 72 and 74, White focusses his attention back on his now beleagered center group with 76 to 80.

White 80 received some criticism, but, since Black's center stones are very strong as the subsequent moves in the game clearly demonstrated, it probably would be better to simply jump to A.

Black 87 and 89 were a brilliant combination.

                         Dia. 58

Instead of 87, Black could have jumped to 1 and played the sequence to 13, leaving White's group without eyes. However, compared to what happened in the game, Black's wall (the marked stones) is significantly weaker, as it has a defect at 'a'.

                         Dia. 59

After Black 1, White can also force with 2 and 4, then switch to 6, wrestling away the initiative from Black. In the worst case, White can play at 'a' to live.

                         Figure 14 (90–100)

Figure 14 (90–100)
Black 95 was a severe move. This is the reason that White should have played 80 (the marked stone) at 95.

It is now easy to see that the exchange from Black 83 to White 98 was extremely good for Black. White's 'wall' on the inside is doing nothing, while Black's wall on the outside is working efficiently to attack the eyeless white group in the center. This is the reason that Black could take and keep the initiative, thereby winning the game.

                         Dia. 60

If White pushes with 1, then plays a hane with 3, Black 4 and 6 are a devastating combination. White's group in the center is doomed.

                         Dia. 61

Black has various ways of attacking White's center group, but the direction is important. In this diagram, Black ignores the principle that a wall should be used for attacking, not for making territory. In addition, this 'territory' is still open at 'a', so White will be able to make a sizable incursion into it.

                         Figure 15 (101–115)

Figure 15 (101–115)
From 99 in Figure 14 to 3 in Figure 15, Black starts a severe attack.

White 4: White is clearly in trouble.

Black 5 was a cautious move.

Before deciding on his strategy on the right side, White plays 6 as a probe.

Black 7 and 9 are a good combination. Black 9 neutralizes most of his bad aji on the right side while making territory and taking away White's eyes in this area.

To eliminate the threat of a double cut at A, White attaches at 10.

Black 15 is the honest move that leaves no bad aji behind.

                         Dia. 62

Black could have chosen a very aggressive variation, e.g. by cutting with 1. However, this would lead to hair-raising fight when White attaches at 'a'.

                         Dia. 63

Instead of 6 in Figure 15, White could have settled his group with the sequence to 11, but Black would then have sente to play around 'a'. In the process, the aji of White 'b' might disappear. Gu probably felt that he could not afford to give Black the entire right side and also sente. If his center group were stronger, instead of White 1 and 3, he would probably have played 1, followed by the two-step hane of 4, which is much more severe.

                         Dia. 64

Pushing with White 1 is bad. After Black draws back with 2, White has to defend against the double cut of Black 'a' with 3. Black just strengthens his group with 4. This is too easy for Black.

                         Dia. 65

Instead of 6 in Dia. 64, blocking with 1 is also out of the question, as Black just cuts with 2 to 6. Black is now aiming to play the sequence from 'a' to 'e'.

                         Dia. 66

If White pushes with 1, Black can aim at cutting with 4 to 8, leading to a capturing race after White cuts with 'a'–Black 'b'–White 'c'–Black 'd'–White 'e'. However, Black seems to have more liberties.

                         Dia. 67

Instead of 15, Black 1 was mentioned as a possible defense, but it still leaves behind some aji — later on, White can peep at 2.

                         Figure 16 (116–119)

Figure 16 (116–119)
Black 17 is a textbook example of a leaning attack. Lee has taken firm control of the game. White has no choice but to reinforce his center group with 18.

                         Dia. 68

If White answers Black 17 in Figure 16 by following the joseki with 1, he has no answer to Black 2, which is a perfect splitting attack.

                         Figure 17 (120–131)

Figure 17 (120–131)
With 16 and 18 in Figure 16, White has made some space to live. There is also the possibility of cutting off Black's marked stones, so White now returns to the fight on the right by playing 20.

Black doesn't waste time and immediately cuts White off with 21 to 25.

However, when White plays 26, Black's stones suddenly look like they are surrounded.

                         Dia. 69

If Black plays 1 instead of 21 in Figure 17, White 2 is a good move, as it threatens to isolate the four black stones on the left by playing at 'a'. Note also that White's stone in the upper left corner is not dead yet. At the right time, he can also play 'b' to 'f' to revive it.

                         Dia. 70

Black 1 looks like a safe move, but White can break up the right side with the moves from 2 to 8.

                         Dia. 71

Black might also defend the left side with 1, but, after White 4, it gets complicated again.

                         Dia. 72

After Black 25, White can't attach with 1 because he loses the capturing race after Black plays 8. However, this could be a threat should the conditions around here change.

                         Dia. 73

Black can also play 1 to attack White's center group. If White now cuts with 2 and 4, Black can live with 5 to 9, but White gets sente. Still, this looks dangerous for White. However, if Black does play 1 —

                         Dia. 74

White will probably attach with 2, leaving Black no choice but to cut with 3 and 5. After White 6, Black has no move that would quickly kill White's stones. However, if he settles his position on the upper right side with 7, after White 8, Black's group in the center looks dead.

                         Dia. 75

If Black jumps to 1, White can cut with 2 and 4. Black can live with the sequence to 9, but White will attack Black's group at the top with 10, leading to a complicated fight.

                         Dia. 76

The reason for the marked stone (Black 27 in Figure 17) becomes clear in this diagram. If White cuts off Black's center group with 1 to 5, Black can kill White's stones with the sequence to 30. Instead of Black 2 —

                         Dia. 77

Black can also answer White 1 with the hane of 2. The moves to 9 show one possible continuation, but Black's marked stone is in a better place to fight than at 'a'.

                         Dia. 78

After White cuts with 30 in Figure 17, Black can also descend to 1 to make eyes for his group on the upper right side. He does not have to be afraid of 2 and 4, because Black can play 5 and 7 and easily win the capturing race.

                         Figure 18 (132–143)

Figure 18 (132–143)
After playing 39, Black's group in the center is safe. There now remain two weak white groups against one weak black group. Obviously, White has to attack Black's group at the top, so he plays 40.

White could also play 40 at 'a'. This would have been safer, but it gives more space for Black to live. However, Gu, who is behind, must choose the severest move.

Black 41 and 43 are a common tesuji combination to cut off White's stone at 40.

                         Dia. 79

Instead of 33 in Figure 18, defending the right side with Black 1 leaves behind a lot of aji. For example, White can attach with 4. If Black answers with 5 to 9, White gets sente to attack (and probably kill) Black's group at the top with 10.

                         Dia. 80

If White connects at 1, Black can extend to 2, putting White's center group in mortal danger. Black can make an eye at 'a' in sente, so, if White wants to kill Black's center group, he has to save his marked stone. However, Black rebuffs him with 4 to 8. It now becomes obvious that Black's marked stone was a very important forcing move.

                         Dia. 81

White can also extend all the way to 5, but Black 6, 8, and 10 are a good combination. White can take the corner with the moves to 17, but Black kills White's center group with 18 and 20.

                         Dia. 82

Instead of 39, Black can also play 1. At the moment, the combination from 3 to 9 works, but it leaves behind more aji than the sequence played in the game.

                         Figure 19 (144–157)

Figure 19 (144–157)
White 44 and 46 are painful preparatory moves so that his group in the center can make two eyes.

After White 48, Black can't cut through because of the presence of 46.

Black 49 and 51 are an 'expensive' combination to get sente so that he can cut with 53 and escape with 55. In the last 10 moves, Black has secured the upper left corner while White has taken the top right corner.

White 56 is a bad move because, as it gives Black a perfect answer with 57.

                         Figure 20 (158–174)

Figure 20 (158–174)
Around move 62, both players appear to be in byoyomi (overtime) and the pace of the game picks up.

In the sequence from 58 to 74, White makes life for his group in the center, but Black is leading by a few points.

                         Figure 21 (175–184)

Figure 21 (175–184)
Making an extra eye with 78 and 80 is the better choice.

Black 83 makes miai between linking up at A and B. This puts Black definitely in the lead.

White 84 is necessary to live.

                         Dia. 83

Instead of 73 in Figure 21, White can also live in a seki with the sequence from 1 to 9. However, White gets no territory, while Black gets many forcing moves, such as 10, 12, and 14, in sente.

                         Dia. 84

If White omits 84 plays elsewhere, Black kills White with the sequence from 1 to 13.

                         Figure 22 (155–200)

Figure 22 (185–200)
Both players are making the best endgame moves.

Black 101 may look strange, but if White ataries at A, Black B is absolute sente. White must capture at C or he will lose the corner.

                         Dia. 85

The placement of Black 1 can't kill White because of the throw-in tesuji of 4 and the atari of 6. Black can't connect at 4 because he is short of liberties.

                         Figure 23 (202–221)

Figure 23 (202–221)
Apparently the Korean pros were laughing when Black played 9. Lee just can't help himself — he has to keep attacking. Still, it is a good endgame move.

It might seem strange that Black doesn't connect the ko when White ataries with 20, but this is a ko that White can't win because connecting at A is absolute sente.

                         Figure 24 (222–251)

Figure 24 (222–251)
White 22 to 28 are a nice tesuji combination, but it is not enough for Gu to overcome the deficit.

By ignoring 49 and playing at 50, Gu Li made a reading 'mistake' that was too simple to be unintentional. In any case, he couldn't win. Black wrapped up the game with 51.

There is no good response to 51. If White plays A, Black throws in a stone at B. If White captures with C, Black can make a seki with D. In addition, he can make a seki by exchanging E for White F.

After Black B, the best White can do is to play at D and make a ko. If Black wins the ko, it becomes a seki, worth about 18 points.

Seeing 51, Gu Li resigned.

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