Iyama Yuta wins 40th Gosei, 3rd victory against Yamashita Keigo in 2015

Iyama Yuta 9p defended his Gosei title, defeating Yamashita Keigo 9p with a 3-1 score in the 40th Gosei title match.

Game 4 of the final was played on August 07, 2015, in Tokyo, Japan, and Iyama Yuta won by resignation after 122 moves.

Iyama Yuta 9 dan (left) and Yamashita Keigo 9 dan at the 40th Gosei final.

Iyama Yuta 9 dan (left) and Yamashita Keigo 9 dan at the 40th Gosei final.



Title deciding game

Game 4 was very exciting with chain battles from the beginning of the game.

Yamashita started attacking White’s reducing stones from the top, but Iyama cut in the center and fought back, and he took the lead of the game from there.

Iyama was holding the initiative of the game for a while, but Yamashita made a nice counter with 83, and the game became very complicated.

However, Yamashita played a thank you move at 97, and the game was suddenly ended very soon afterwards.

Iyama is becoming the natural enemy of Yamashita

Iyama Yuta 9 dan at the 40th Gosei final.

Iyama Yuta 9 dan at the 40th Gosei final.

Iyama Yuta and Yamashita Keigo already played each other in the 39th Kisei final and the 70th Honinbo final in this year.

Iyama barely defended the Kisei title with a 4-3 score. Iyama won the first three games, but Yamashita won next three games to go to the title deciding game.

Yamashita was looking for a reverse sweep with his sweeping upturn, but Iyama didn’t let it happen with his victory in game 7 in March, 2015.

In the 70th Honinbo final, Yamashita was challenging again, but Iyama defended easily with a 4-1 score in June, 2015.

This Gosei final was their 3rd title match in 2015, but Yamashita didn’t get revenge for his earlier defeats. It looks as if Iyama is becoming the natural enemy of Yamashita.

Yamashita is still superior against other top Japanese players, but only except against Iyama. Apparently, that doesn’t seem easy for Yamashita to overcome since he’s more than 10 years older than Iyama.

The goal of Honorary Gosei

With this victory, the goal of becoming Honorary Gosei, by defending the title for one more year, is within Iyama’s grasp along with the Honorary Honinbo.

The title of Honorary Gosei is bestowed upon players who hold the Gosei title for five years in a row.

Since 1976, only two players have received this title, including: Otake Hideo 9p and Kobayashi Koichi 9p.

Iyama Yuta 9 dan (left) and Yamashita Keigo 9 dan, just after the final game finished.

Iyama Yuta 9 dan (left) and Yamashita Keigo 9 dan, just after the final game finished.

The 40th Gosei Series

Game 1

White 12 to 16 were the new style of play, and the attachment at White 22 was sharp.

White 36 was sharp, and Black 37 to 39 were fighting spirits.

White 40 was questionable, and that should be better to cut at 43 to make a ko.

Black 57 and 59 were practical, and Black took the lead up to 75.

Cutting at Black 83 was a nice tesuji, and Black solidified his lead up to 87.

White 98 and 100 were severe attack, but Black 99 and 101 were sharp and creative to invade and live on the left side.

The sequence from Black 155 to 167 was brilliant, and the game was decided.

Iyama Yuta vs Yamashita Keigo – Game 1


Download SGF File (Go Game Record)


Game 2

Black 9 t0 15 were unusual, and Black 17 and 19 were creative.

White 20 was questionable, because White’s right side group became weak after Black 23.

The opening up to Black 37 was favorable for Black.

Black 55 was practical, and Black 75 was very nice to threaten White’s weaknesses.

White 86 and 88 were strong, and a big ko fight was emerged up to Black 103.

White 108 was the losing move, because that ko threat didn’t work.

Black’s sabaki from 115 to 125 were sophisticated, and Black 131 to 135 were calm and accurate.

White went all out with 172, but Black captured White’s huge dragon up to 179, and White soon resigned.

Yamashita Keigo vs Iyama Yuta – Game 2


Download SGF File (Go Game Record)


Game 3

Black 19 and 21 were strong, and the result up to Black 39 was slightly better for Black.

Black  49 t0 65 were good sequence to make a ko, and the trade up to Black 87 was still favorable for Black.

White’s cutting from 88 was severe, and the game became more complicated up to White 102.

Black 121 was necessary to take care of this group, and White 134 was a good sequence, and the result of the ko fight up to 164 was successful for White.

Black 171 and 173 were a good decision, and the game was still slightly better for Black up to 191.

Black 193 was careless, and White 194 was a nice response to take sente.

However, Black 201 to 213 were bold and accurate, and Black successfully reduced White’s territory up to 222 in sente.

Black 223 was big, and Iyama’s endgame was perfect to save the small margin.

Iyama Yuta vs Yamashita Keigo – Game 3


Download SGF File (Go Game Record)


Game 4

The opening was well balanced between territory and influence, and Black started to attack White’s reducing moves with 21 and 23.

Black 31 was interesting, and White 32 was the correct response.

White 36 and 38 were nice haengma, and White took the initiative of the game with 46.

Attaching at White 56 was a nice tesuji, and the result up to Black 65 was successful for White.

White 78 and 80 were too much, and Black 83 was a nice counter.

White played strongly from 86 to 92, and the game became very complicated.

Black 97 was a crucial mistake, and that should be hane at 99.

White 100 and 104 were cool and flexible, and Black’s big dragon became in great danger up to White 116.

Yamashita couldn’t find any way to save his dragon, and he soon resigned.

Yamashita Keigo vs Iyama Yuta – Game 4


Download SGF File (Go Game Record)


Reviewing the game after the final game finished.

Reviewing the game after the final game finished.

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About Younggil An

Younggil is an 8 dan professional Go player with the Korean Baduk Association. He qualified as a professional in 1997 and won an award for winning 18 consecutive professional matches the following year. After completing compulsory military service, Younggil left Korea in 2008, to teach and promote the game Go overseas. Younggil now lives in Sydney, Australia, and is one of the founders of Go Game Guru. On Friday evenings, Younggil is usually at the Sydney Go Club, where he gives weekly lessons and plays simultaneous games.

You can follow Go Game Guru on Facebook, Twitter, Google+ and Youtube.


  1. Black’s fuseki in game 2 was Fan Hui’s favorite when he was younger 😉

    In game 3, Iyama played a cross opening with “facing komoku” (i.e. white d17 and black d3). I was taught that most pros think that cross opening is nice for white. I think this is true because white rarely avoid cross fuseki and black rarely play it. Why would Iyama play a slightly inferior fuseki ?

    • For one thing, it’s pretty much hearsay, that a diagonal fuseki is inferior for black.(Maybe it’s just too early in the 21st century for Go Seigen’s diagonal san-ren-sei 🙂 )
      Another thing is that, as in game 3, black very often creates an opposing komoku position, when playing a diagonal fuseki. If white takes the fourth coner, black gets the first move to continue there.

    • Younggil An says:

      Thanks bfm and Stefan for the question and answer.

      The cross opening is still be seen when White plays 3-4 for the 2nd move like D17. That’s because Black’s approach after Black D3 is nicer than other cases such as approaching to a star point.

      That’s why Iyama chose the diagonal opening, and that’s still another even game.

  2. Iyama’s play looks very confident. He seems to make shape effortlessly.

  3. Younggil An says:

    Yes, I felt so too, and that’s understandable with his strength. 🙂

  4. Instead of move 20 in game 2, what would be better? If Q15, black gives way at P16 it doesn’t look particularly nice. Should white just patiently block at S14? Not sure how black would continue then, so it appeals to me locally… though I’d worry about the black moyo below.

    • Younggil An says:

      It looks like blocking at S14 is normal for White 20, but Iyama wanted to get more, so he attached at 20.

      However, Yamashita’s responses were nice and flexible, and Black had slightly better start I think.

      That’s very subtle, so hard to see which move was problematic in that situation.

  5. Anonymous says:

    Btw in game 2 I loved the way Iyama just ignored white’s invasion at J3 (move 40) and took the key whole-board point.

    In game 3 I suppose 193 should be O12 to keep sente? I though Iyama had fallen behind here, but R8 (white 200) seemed cautious. I realise there is bad aji around N9, but is R8 really the best white can do? Anyway, Iyama’s yose after 200 was awesome.

    • Younggil An says:

      That’s a good point that White 200 from game 3 was cautious. I was also wondering about that move, but I couldn’t find any better move for White, because of the bad aji in the center area as you mentioned. It was hard to find White’s losing move in that game.

  6. (last comment mine)

  7. As a complete aside, there is a recent rather exciting game between Imamura Toshiya and Yu Bin that I think contains a lot of material that would repay amateur dan-level study.


    • Younggil An says:

      That game looks interesting, and thanks Hippo for sharing the game with us here. 🙂

      • Yes. It even includes my favourite tesuji in a variation: if black blocks at L2 for move 69 on the face of it white’s invasion is lost as the semeai is unfavourable (the stone at F2!). But… well I won’t spoil the problem for anyone interested in having a look 🙂



  8. Bug report: on IE (but not on Mozzarella Firefox) the move numbers overwrite each other creating an illegible black smudge… I am on IE version 11.0.96 (update version 11.0.22)

  9. Yup, thanks.

  10. Tomorrow begins Iyama’s last title defense of the year. And it will be Takao Shinji’s turn tomorrow to try and topple the Iyama Hegemony in the Meijin Title match. Mr. An what do you think is the way to beat Iyama? Yamashita Keigo’s creative attacking style does not work? But could Takao’s steady and calculating game make any difference? I’m so excited for the start of the Meijin title match tomorrow. Woohoo!

    • Younggil An says:

      Yes, that Meijin title match will be interesting.

      Takao’s style of play seems to be more difficult for Iyama to play against, but Iyama will still have the edge on Takao I think.

      Let’s see how it’s going on. 🙂