Lee Sedol

    Keywords: People

Chinese: 李世石
Japanese: イ・セドル
Korean: 이세돌
M-R: Yi Se-tol
RR: I Se-dol

Lee Sedol (b. March 2, 1983) is a professional Korean 9-dan. He is known for being regarded as the best player in the world from 2007–2008 and 2011–2012; for his strong fighting style; influence on the contemporary development of fighting; and international rivalry with Gu Li.[1] In March 2016, he was the “representative of humankind” in the famous AlphaGo challenge series that ended 1–4. In November 2019, he announced his retirement from professional play.[3] As of February 2016, he ranked second in international titles (18), behind Lee Chang-ho (21). His nickname is “The Strong Stone” (“Sen-dol”).

Table of contents

Rank Promotion

  • 1-dan: 1995
  • 2-dan: 1998
  • 3-dan: 1999
  • 6-dan: 2003, March — For winning the 7th LG Cup
  • 7-dan: 2003, May — For runner up in the KT Masters Cup
  • 9-dan: 2003, July — For winning the 16th Fujitsu Cup

Major titles

Other Titles

Samsung Cup 2004

Since he beat Lee Changho for the LG Cup in the early 2003, this was his first major win, domestic or international, and it is his 4th major international title. What is striking is his control of pace in the final match against Wang Xi 5d of China whose style is similar to that of Lee Changho. Instead of the usual aggressive style of slugging out from the very beginning, he demonstrates patience and balance waiting for a chance to crush the opponent in the mid game -- and he does. The second game was fun to watch. His fans will love his razor sharp attack into the mid game. Also, the semi-final match between Gu Li 7d of China and him is highly entertaining. After winning the first game, they play the second game like blitz (the first game was played quite quickly, as well), and Gu Li won before lunch break! Then, Lee turns deliberate and methodically defeats Gu Li in the decisive game.

Ascending the throne

Lee Sedol has been widely considered as a forerunner of the new Korean players who can challenge and even surpass Lee Changho. In 2003, he has proven it by winning two world competitions, the LG Cup and Fujitsu Cup. Perhaps more significant than just winning the titles, he defeated Lee Changho by 3–1 in the final of LG Cup. Considering that Lee Changho has been almost unbeatable in the finals, especially in a 5 game series, many consider it as a beginning of a new era of Korean Baduk (Go), the truth of which we will have to wait and see.

2009–2010 Hiatus

In the first days of June, several Korean sources claimed that Lee would take a 1.5-year break. This was later confirmed by Sedol. The break was partially the result of some disputes between Sedol and the Hanguk Kiwon. He was expected to start playing again in January 2011. [ext] See also here


He returned to active Go playing in 2010, a year earlier than expected. Far from having a negative effect on his strength, he appears to have come back even stronger. As of 27 April 2010, he has not lost a single game this year! (24 wins in a row, including 12 games in international tournaments). As of 4 June 2010 he obtained his 800th win in career (11th player of the Hankuk Kiwon. [ext] See also here). Complete win/los record at the end of 2009 is [ext] here.

Playing Style

Lee is thought to be as talented as Cho HunHyun (thought to be the most talented player of his generation). Lee is as intuitive. He is as quick and deep in reading. He is as lethal in battles. He is as masterful at creating and handling chaotic warfare.

However, the most interesting aspect of his game lies in his risk-loving tendency. Most top ranking Go players would not jump into a showdown battle of uncertainty unless absolutely necessary. In that sense, they are risk-averse.

For instance, Lee Changho is the very definition of risk aversion. He is a master of defense. He is a master of transforming a chaos into a simple, orderly universe.

Yoo ChangHyuk has been considered as a most offensive minded player. However, his attacks are brought about only when he has a positional superiority (thickness). At the same time, his attacks are not designed to create decisive battles. He sticks to an old saying: “chase enemies leaving an escape route.” Desperate enemies without an escape route present do or die struggles, and Yoo does not want the situation. In other words, Yoo’s battles, by design, are a way to accumulate advantages, rarely a way to deliver a knock out blow. He is risk-averse contrary to a popular belief.

Cho HunHyun has a style of Sugar Ray Leonard. He has dazzling footwork (soft wind—fast movement both in the opening and in the mid-game development) and penetrating jabs followed by a knock out blow (a quick spear—a ruthless thrust into the enemy’s tinest weakness). As he suffered worst defeats by Lee Chang Ho, his own pupil, Cho’s style has become even grittier earning a nickname of “God of War” (in order to deliver a fatal thrust in the mid-game and thus minimize the importance of the endgame at which Lee has no peer). Nevertheless, Cho’s style still reflects that battles are “resultant of” positional struggles in the opening or in the mid-game. He has also said that he would seek a best move even if he were ahead, and the move added additional uncertainties and therefore risk. He is risk neutral.

Lee Sedol is somewhat similar to Cho in style, which prompted some Korean critics to nickname him as “Little Cho”. Lee does have an ability to deliver a quick, brilliant thrust of Cho’s. At the same time, Lee and Cho have an uncanny resemblance in the ability to “shake” (“shaking”, literally translated from a Korean expression, means waging chaotic all out battles at the end in an attempt to turn the tide of the war).

However, a critical difference between the two is that while Cho is more orthodox and conventional in his view of the mid-game such that battles are a consequence of positional struggles, Lee emphasizes battles such that positional struggles are simply a prelude of a decisive battle and can even be forsaken. It can often be observed that Lee engages in battles shortly after the opening without ensuring positional superiority nor out of necessity to make up for an inferior position. More often than one may suspect, positions are determined by the battles in Lee’s games. At the same time, unlike Yoo (or Cho to some extent), Lee’s vicious attacks are designed to be decisive instead of to be a way to maintain or shift positional superiority without engaging in do or die showdowns.

In other words, Lee is a risk lover. And that means exciting games for fans.

One interesting tidbit is that Lee’s aggressive, risk-taking style reflects a stereotype of Korean Go tradition which has been thought to be amateurish and inferior to all encompassing, well rounded, mostly risk averse modern styles (e.g., those of the Korean players mentioned above).


Lee’s weaknesses have also been exposed. First of all, his judgement of position is not of top notch—again relatively speaking, that is. Perhaps because of this, he has chosen to live and die with showdown battles. Or, his aggressive disposition/preference and hence the style have prevented him from studying this particular aspect of the game. Whichever is true, it seems that the relative deficiency in perhaps the most important aspect of the game may prove to be his biggest obstacle to win consistently against top rated players.

Secondly, he appears to turn overly pessimistic when things do not go as he planned. Combined with the deficiency discussed above, this once led him to resign in 106 moves, and he was thought to be still ahead in the game even by his opponent. In other words, he can be emotional and displays the lack of objectivity from time to time. This tendency may prove to be another obstacle for him to win consistently.

Lastly, he is not as studious and relies too heavily upon his talent. This will hinder his growth as a Go player and may not help him to accommodate changes necessary to stay afloat in the long run. Lee Changho has been able to survive on the top over a decade mainly because his constant study of Go has deepened and broadened his game. Can Lee enjoy such longevity relying on talent alone? Considering that Cho HunHyun, a natural, had to redefine himself (and still is outclassed by Lee Changho) in order to survive the onslaught of the 90s in the Korean Go scene, Lee Sedol will have to further his game and possibly reinvent himself in the future.

At any rate, there is no doubt that Lee Sedol is the most exciting player in Korea right now. He is explosive, creative, daring, powerful, and flamboyant. His game is strong enough to even psychologically affect Lee Changho. His brilliance is radiant enough to beat Cho HunHyun? eight times in a row. His palettes are diverse enough to have already won three world competitions and many fans (some of whom are so conservative that they would normally chide and defy a kid like Lee who lacks modesty and humility in a traditional sense).

Recommended Games

  • [ext] The semi-final match of the 16th Fujitsu Cup between Lee and Yoda Norimoto. It is by no means a well played game by either player. Nevertheless, it is luminary of Lee’s style and tendencies, good and bad. Shortly after the opening and some rudimentary development of sides, Lee starts complicating a situation. Yoda makes a mistake (or lets a big battle occur while taking material advantages). Lee splits Yoda’s group and goes for the neck. Then, facing Yoda’s skillful dodges, Lee turns pessimistic and settles for the lesser group of Yoda’s (Lee could have ended the game by capturing the bigger group but somehow missed not so difficult capturing moves), which puts Lee into a deep trouble materially. Then, Lee engages in a rather complicated “shaking”, and Yoda under time pressure makes a mistake. The game ends in favor of Lee by a half house (point).
  • Lee is known as one of the most creative players. See the highlights of his “weird” blitz game against Hong Chang-sik. See [Lee Sedol – Hong Chang Sik - ladder game].
  • [ext] 1st game of final of 2nd BC Card Cup against Chang Hao. An exciting game with plenty of sacrifices and trades. Lee is on top of his game, totally outplaying another top 9 dan.



lee sedol 8th chunlan cup 2011 (Image credit: 0)
lee sedol 8th chunlan cup 2011 (Image credit: Foxwq.com)

lee sedol (Image credit: 2)
lee sedol (Image credit: Foxwq.com)

lee sedol (Image credit: 4)
lee sedol (Image credit: Foxwq.com)

alphago lee sedol 2016 (Image credit: 6)
alphago lee sedol 2016 (Image credit: Foxwq.com)


[1] Lee Sedol - Gu Li Rivalry
[2] In February 2013, Lee announced that he was planning to retire in three years and move to the US to promote go. Source: An Younggil's [ext] translated interview at Go Game Guru). [3] Source: [ext] https://www.theverge.com/2019/11/27/20985260/ai-go-alphago-lee-se-dol-retired-deepmind-defeat

Lee Sedol last edited by Jono64a on June 12, 2024 - 02:49
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