Thank you, pookpooi! I'm looking forward to seeing that game then

_________________

I wonder if somebody could break down the reasons for the early resignation in this game?

What I do think I understand is that Black violently set out to kill something and failed. As a result, Black lives small on the top and White is likely to get a lot of of territory at the bottom. Black might not be able to resist at the bottom because his O6 group still has to bother about making two eyes. On top of that, Black probably can't expect a lot of points on the left side because White has already spilled in.

So from my limited understanding, Black went all out and ended up strategically busted? Is this roughly what happened here? It still strikes me as early but what do I know...

It is a weird game, I was surprised Yang just gave up the key cutting stones in the centre fight. I've got more questions (see forum/viewtopic.php?p=225051#p225051) than answers, but here's some preliminary analysis. If not for the resign, perhaps the game would continue like so. It's painful to answer but I think 3/5 are probably sente or black's right side group is going to end up tiny in sente (actually maybe not if black has a to capture the 2 marked stones?).

Click Here To Show Diagram Code

[go]$$W Iyama Yuta (white) vs Yang Dingxin
$$ +---------------------------------------+
$$ | . . . . . . . . . . O . . . . . O . . |
$$ | . . . . . . . . . O X X X O X . X O . |
$$ | . . . O . O O X . O X O O O X X O . . |
$$ | . . . , O . X O . O O X X X . X O . . |
$$ | . . X X . X X O . O X X . X . X O . . |
$$ | . . . O X . O X X X O . . . O O X O . |
$$ | . . . . X . O O . X O . O O . . X O . |
$$ | . . . . . . . . . X . . . X X . X 5 . |
$$ | . . . X . X X . . . . O . . . . 6 . . |
$$ | . . . , . O X X X X O a W . . , . . . |
$$ | . . . . . O O O O X O X W . . X . . . |
$$ | . . . . . . . . X O O X . . . . . . . |
$$ | . . . . . . X O X . . X O . . . 4 . . |
$$ | . . . . . . X O . O O X X X 2 X . 3 . |
$$ | . . O . . O O . . . . O O . 1 . . . . |
$$ | . . O X . . . . . , . . . . O X O . . |
$$ | . X X . . X O . . . . . . . . . O . . |
$$ | . . . . X . X O X . . . . . . . . . . |
$$ | . . . . . X . . . . . . . . . . . . . |
$$ +---------------------------------------+[/go]

Anyway, if white can get those exchanges in that's a bonus, but probably then with the exchange of 1 for 2 white has fixed the bad aji in the bottom that he could descend and make a large lower side if black can't live inside? Let's say white isn't scared of ko.

Click Here To Show Diagram Code

[go]$$W White happy with big territory
$$ +---------------------------------------+
$$ | . . . . . . . . . . O . . . . . O . . |
$$ | . . . . . . . . . O X X X O X . X O . |
$$ | . . . O . O O X . O X O O O X X O . . |
$$ | . . . , O . X O . O O X X X . X O . . |
$$ | . . X X . X X O . O X X . X . X O . . |
$$ | . . . O X . O X X X O . . . O O X O . |
$$ | . . . . X . O O . X O . O O . . X O . |
$$ | . . . . . . . . . X . . . X X . X . . |
$$ | . . . X . X X . . . . O . . . . . . . |
$$ | . . . , . O X X X X O . O . . , . . . |
$$ | . . . . . O O O O X O X O . . X . . . |
$$ | . . . . . . . . X O O X . . . . . . . |
$$ | . . . . . . X O X . . X O . . . . . . |
$$ | . . . . . . X O . O O X X X 2 X . . . |
$$ | . . O . . O O . . . . O O . 1 . . . . |
$$ | . . O X . . 6 7 . , . . . . O X O . . |
$$ | . X X . . X 8 4 5 . . . . . . . O . . |
$$ | . . . . X . X O X 9 . . . . . . . . . |
$$ | . . . . . X . 3 . . . . . . . . . . . |
$$ +---------------------------------------+[/go]

Can black resist and live inside? If it weren't for the 1-2 exchange probably 8 was sente, but now it's not so a kill looks more plausible. This still looks like a sufficiently difficult life and death problem that you could play it out before resigning though.

Click Here To Show Diagram Code

[go]$$W Iyama Yuta (white) vs Yang Dingxin
$$ +---------------------------------------+
$$ | . . . . . . . . . . O . . . . . O . . |
$$ | . . . . . . . . . O X X X O X . X O . |
$$ | . . . O . O O X . O X O O O X X O . . |
$$ | . . . , O . X O . O O X X X . X O . . |
$$ | . . X X . X X O . O X X . X . X O . . |
$$ | . . . O X . O X X X O . . . O O X O . |
$$ | . . . . X . O O . X O . O O . . X O . |
$$ | . . . . . . . . . X . . . X X . X . . |
$$ | . . . X . X X . . . . O . . . . . . . |
$$ | . . c , . O X X X X O . O . . , . . . |
$$ | . . . . . O O O O X O X O . . X . . . |
$$ | . . a . . . . . X O O X . . . . . . . |
$$ | . . . . . . X O X . . X O . . . . . . |
$$ | . . . . . . X O . O O X X X 2 X . . . |
$$ | . . O b . O O . . . . O O . 1 . . . . |
$$ | . . O X . . . . 6 , . . . . O X O . . |
$$ | . X X . . X O 7 5 4 . . 9 . 8 . O . . |
$$ | . . . . X . X O X . . . . . . . . . . |
$$ | . . . . . X . 3 . . . . . . . . . . . |
$$ +---------------------------------------+[/go]

As for the left side, black's not going to make much there, some extension on the side around a above and connecting/cutting the 2 stones at b are kind of miai (and if black a white b then there's still some problem at c).

So if I try to simplify the game to get a countable position I might get something like this with the following caveats: 5-6 a bit generous to white, 7 based on premise black can't live inside.

Click Here To Show Diagram Code

[go]$$W
$$ +---------------------------------------+
$$ | . . . . . . . . . . O . . . . . O . . |
$$ | . . . . . . . . . O X X X O X . X O . |
$$ | . . . O . O O X . O X O O O X X O . . |
$$ | . . . , O . X O . O O X X X . X O . . |
$$ | . . X X . X X O . O X X . X . X O . . |
$$ | . . . O X . O X X X O . . . O O X O . |
$$ | . . . . X . O O . X O . O O . . X O . |
$$ | . . . . . . . . . X . . . X X . X 3 . |
$$ | . . . X . X X . . . . O . . . . 4 . . |
$$ | . . . , . O X X X X O . O . . , . . . |
$$ | . . . . . O O O O X O X O . . X . . . |
$$ | . . . . . . . . X O O X . . . . . . . |
$$ | . . . . . . X O X . . X O . . . 6 . . |
$$ | . . . . . . X O . O O X X X 2 X . 5 . |
$$ | . . O . . O O . . . . O O . 1 . . . . |
$$ | . . O X . . 0 . . , . . . . O X O . . |
$$ | . X X . . X O 8 9 . . . . . . . O . . |
$$ | . . . . X . X O X . . . . . . . . . . |
$$ | . . . . . X . 7 . . . . . . . . . . . |
$$ +---------------------------------------+[/go]

14 could be overplay as black might fight ko, but actually as capture at 16 is sente it wasn't so important to get 11 atari and could just 13 as seems 2 centre stones still can't escape.

Click Here To Show Diagram Code

[go]$$Wcm11
$$ +---------------------------------------+
$$ | . . . . . . . . . . O . . . . . O . . |
$$ | . . . . . . . . . O X X X O X . X O . |
$$ | . . . O . O O X . O X O O O X X O . . |
$$ | . . . , O . X O . O O X X X . X O . . |
$$ | . . X X . X X O . O X X . X . X O . . |
$$ | . . . O X . O X X X O . . . O O X O . |
$$ | . . . . X . O O . X O . O O . . X O . |
$$ | . . . . . . . . . X . . . X X . X O . |
$$ | . . . X . X X . . . . O . . . . X . . |
$$ | . . . , . O X X X X O . O . . , . . . |
$$ | . . . . . O O O O X O X O . . X . . . |
$$ | . . . . . . . . X O O X . . . . . . . |
$$ | . . . . . . X O X . . X O . . . X . . |
$$ | . . . . . . X O 7 O O X X X X X . O . |
$$ | . . O . . O O 6 . . . O O . O . . . . |
$$ | . . O X . . X 1 4 , . . . . O X O . . |
$$ | . X X . . X 2 X O 5 . . . . . . O . . |
$$ | . . . . X . X O X 3 . . . . . . . . . |
$$ | . . . . . X . O . . . . . . . . . . . |
$$ +---------------------------------------+[/go]

Because of the cut of 16 black could fight more instead of making left territory with 18, but just for sake of argument let's say he cashes the aji to close the territory and white is obedient... Also white answering 22 at 23 is maybe passive, and maybe black would hane and live in the corner but then the left side is damaged and I don't want to count that.

Click Here To Show Diagram Code

[go]$$Bcm18
$$ +---------------------------------------+
$$ | . . . . . . . . . . O . . . . . O . . |
$$ | . 6 8 . . . . . . O X X X O X . X O . |
$$ | . 5 . O . O O X . O X O O O X X O . . |
$$ | . 7 . , O . X O . O O X X X . X O . . |
$$ | . . X X . X X O . O X X . X . X O . . |
$$ | . . . O X . O X X X O . . . O O X O . |
$$ | . . . . X . O O . X O . O O . . X O . |
$$ | . . . . . . . . . X . . . X X . X O . |
$$ | . . . X . X X . . . . O . . . . X . . |
$$ | . . . , . O X X X X O . O . . , . . . |
$$ | . . . . . O O O O X O X O . . X . . . |
$$ | . . 1 . 3 . . . X O O X . . . . . . . |
$$ | . 9 . . . 4 X O X . . X O . . . X . . |
$$ | . . . . 2 . X O O O O X X X X X . O . |
$$ | . . O 0 . O O X . . . O O . O . . . . |
$$ | . . O X . . X . X , . . . . O X O . . |
$$ | . X X . . X X X O O . . . . . . O . . |
$$ | . . . . X . X O X O . . . . . . . . . |
$$ | . . . . . X . O . . . . . . . . . . . |
$$ +---------------------------------------+[/go]

So counting this position, white has:
- lower side: 33
- middle: 9
- top left: 16 (hmm h18 semedori?)
- top right: 11
- komi: 6.5
Total: 75.5

Black has:
- bottom left: 13
- top right: 9
- right: 6? + if gets m10 12ish (loses a bit at k11) so count as 6 + 12/2 = 12 total
- middle: 13
- left: 25
Total: 72

So my example early endgame and count gets a white lead of 3.5, which is big in pro games, but small considering how much game is left and I'd say my playout could have an error of 5-10 points, particularly as Iyama might destroy the left side more aggressively and perhaps could apply more pressure to the right side group, perhaps finding a way to save the 2 stones in sente. Then again black also has options to be more enterprising. So not resignable at my level, I suspect Yang was psychologically beaten with his fighting plans going awry as much as on the board.

P.S. I wondered here should black have exchanged 2-3 after 1 before extending at 4 to prevent white's break through at a in the game? Maybe white would ignore and sacrifice the tail?

Click Here To Show Diagram Code

[go]$$W
$$ +---------------------------------------+
$$ | . . . . . . . . . . O . . . . . O . . |
$$ | . . . . . . . . . O X X X O X . X O . |
$$ | . . . O . O O X . O X O O O X X O . . |
$$ | . . . , O . X O . O O X X X . X O . . |
$$ | . . X . . X X O . O X X . X . X O . . |
$$ | . . . O . . O X X X O . . . O O X O . |
$$ | . . . . . . O O . X O . O O . . X O . |
$$ | . . . . . . . . . X . . . X X . X . . |
$$ | . . . X . . . . . . . O 3 . . . . . . |
$$ | . . . , . . . . . X . 2 O . . , . . . |
$$ | . . . . . . . . . . a X O . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . X 1 . . . . . . |
$$ | . . . . . . . . . . . 4 . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+[/go]

Update: some analysis by strong bots at forum/viewtopic.php?p=225087#p225087

Just in case someone want game record of Ke Jie vs. Iyama Yuta with FineArt commentary
http://eidogo.com/#1mWabLJQ8

I had a lot of fun analyzing Iyama vs Ke, very good training material for the upcoming tournament in my country. Using the help of DeepZen, I noticed that Ke and Iyama were very much equal throughout the game, but after the big fight on the right side, B (Iyama) was winning. A lot. Seems to me that W (Ke) could've tricked B in the endgame. Anyone have thoughts on this particular position? Or some thoughts on the game?

Wouahhhhhhhh thank you so much, it is helping a lot. In the future i hope I can see more reviews like this ^^

You're welcome there is professional commentary too: https://www.youtube.com/watch?v=nxMBHyFvhP0

A side note: The two commentators, Tan Xiao and Jia Ganglu, just got married.

If they want to stay married I suggest they don't review too many games together .

Apparently if you pay 10,000 yen you can participate in Iyama Yuta's celebration party held by Asahi newspaper on December 13 at Hotel Chinzanso Tokyo http://www.asahi.com/articles/DA3S13229838.html

Commentary of the match against Ke Jie in Japanese: https://www.youtube.com/watch?v=oEkl9CvjlRc

This is a great link! There is a real time commentary by O Meien and towards the end Iyama himself comments on the game.

Igo Premium is a nice service but a bit pricey. At least it's all online and accessible everywhere. I don't have it, so I'm glad someone ripped it at least.

Right now it's him vs. Ichiriki Ryo right? Any comment?

Iyama won game 2 of the Oza vs Ichiriki by 4.5. They both did a taisha, but not the complicated lines. Later Iyama cut and killed Ichiriki's reduction of his centre but had to give up a few nibbles plus some bad aji which meant there was a rather large ko in the endgame.

Thanks for posting these udpates/summaries. I haven't followed any pro games closely lately but I was under the impression that Ichiriko failed to score a win so far in his Tengen(?)/Oza games against Iyama?

He lost to Iyama Yuta for 7 consecutive games. His total count in go4go database is 5/20.

0-7?! That must hurt...

Iyama not exactly invincible though. In my opinion Ichiriki had great chances in today's games.

For the last 7 games, but not of all time, haha.
I would feel bad for Ichiriki Ryo though. Being a top prospect, but having that guy who's always better than you (who is also one of the reasons he's not a 9d yet).

On a side note, I believe Ichiriki was just promoted to 8d last week for winning his 150th game as a 7d. This being against Yamashita Keigo in the finals of the Kisei tournament.