20th Nongshim Cup

[explo]

I don't see how the tesuji at F5 works after Black plays atari on the outside, can anyone explain?

If black plays atari from the outside, white can play atari at F7 and black can't connect, or white will squeeze and capture even more stones.

[hyperpape]

Now
Japan: 6.5%
Korea: 23.1%
China: 70.4%

Previously
Japan: 9.5%
Korea: 25.0%
China: 65.5%

[Uberdude]

Shin ended up in a bad position and never recovered with what seemed like a not so hard direction of play problem. Here's the position, can you do better?

$$Bc Fan Tingyu (black) vs Shin Minjun
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . O . |
$$ | . . . 3 . . . . . . . . . . X O O X . |
$$ | . . 4 . . 1 . . . . X . . O X O X X O |
$$ | . . . O . . . . . , . . . . X X O O . |
$$ | . . . . 5 . . . . . . . . . . . . . . |
$$ | . . 2 . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . X . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . X O . . . . . O . . . . . X . . . |
$$ | . . X O . X O . . . . . . O . . . . . |
$$ | . . X X O O . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+

Click Here To Show Diagram Code

[go]$$Bc Fan Tingyu (black) vs Shin Minjun
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . O . |
$$ | . . . 3 . . . . . . . . . . X O O X . |
$$ | . . 4 . . 1 . . . . X . . O X O X X O |
$$ | . . . O . . . . . , . . . . X X O O . |
$$ | . . . . 5 . . . . . . . . . . . . . . |
$$ | . . 2 . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . X . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . X O . . . . . O . . . . . X . . . |
$$ | . . X O . X O . . . . . . O . . . . . |
$$ | . . X X O O . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+[/go]

Here's my commentary/analysis:

Black just approached with 1 and then 5 was an interesting move, developing the top side on a more ambitious scale than the more normal one-point jump to a (Elf likes that or e16). If white pushes and cuts then that's taking the bait and black just sacrifices and pushes along the g line to grow a big top, so white doesn't dare to cut yet. 5 makes the press at b a stronger follow-up to keep growing the top. Just making a side extension to c to surround a few points would be slack, white's nozomi at d is nice reduction.

So my first thought was to reduce the top side seeing as black is trying to grow it on a large scale: shoulder hit at k16 would be one idea, or maybe something more gentle like k15 or k14 (which if ignored makes the shoulder hit really easy to play with no worry about a capping play or getting heavy). Then I remembered e which is a nice point to reduce against the upper right shape that I learnt from one of the strong bots on CGOS (either define aka Tianrang or monroe and the other US president bots which were later revealed to be test version of Elf) which often liked to take the corner instead of p18 connect in that bot-favourite attach and hane joseki.

$$Bc Fan Tingyu (black) vs Shin Minjun
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . O . |
$$ | . . . 3 . . . . . . . . . . X O O X . |
$$ | . . 4 . . 1 . . . . X . . O X O X X O |
$$ | . . . O . . . c . , . . . . X X O O . |
$$ | . . . . 5 a . . . d . e . . . f . . . |
$$ | . . 2 . . . . . . . . . . . . . X . . |
$$ | . . . b . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . X . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . X O . . . . . O . . . . . X . . . |
$$ | . . X O . X O . . . . . . O . . . . . |
$$ | . . X X O O . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+

Click Here To Show Diagram Code

[go]$$Bc Fan Tingyu (black) vs Shin Minjun
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . O . |
$$ | . . . 3 . . . . . . . . . . X O O X . |
$$ | . . 4 . . 1 . . . . X . . O X O X X O |
$$ | . . . O . . . c . , . . . . X X O O . |
$$ | . . . . 5 a . . . d . e . . . f . . . |
$$ | . . 2 . . . . . . . . . . . . . X . . |
$$ | . . . b . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . X . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . X O . . . . . O . . . . . X . . . |
$$ | . . X O . X O . . . . . . O . . . . . |
$$ | . . X X O O . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+[/go]

Because black exchanged p18 for t17 r15 isn't sente so white has a cut at f, but the right side doesn't look like a scary black potential yet (e.g. q7 shoulder hit) so the r14 stone isn't so important. Rather than cutting it (which black can dodge it would be nice to annoy black's shape and reduce. Here's a dream. In reality black wouldn't 2, 4 is soft, 8 would likely push and cut, so 7 should probably not overplay and be at a or so, but this seems the right sort of idea for white of reducing from the outside.

$$Wc white dream
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . O . |
$$ | . . . X . . . . . . . . . . X O O X . |
$$ | . . O . . X . . . 8 X . . O X O X X O |
$$ | . . . O . . . . . 7 . . 4 6 X X O O . |
$$ | . . . . X . . . a . . 3 5 . . 2 . . . |
$$ | . . O . . . . . . . . . . . 1 . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . X . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . X O . . . . . O . . . . . X . . . |
$$ | . . X O . X O . . . . . . O . . . . . |
$$ | . . X X O O . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+

Click Here To Show Diagram Code

[go]$$Wc white dream
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . O . |
$$ | . . . X . . . . . . . . . . X O O X . |
$$ | . . O . . X . . . 8 X . . O X O X X O |
$$ | . . . O . . . . . 7 . . 4 6 X X O O . |
$$ | . . . . X . . . a . . 3 5 . . 2 . . . |
$$ | . . O . . . . . . . . . . . 1 . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . X . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . X O . . . . . O . . . . . X . . . |
$$ | . . X O . X O . . . . . . O . . . . . |
$$ | . . X X O O . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+[/go]

What Shin played:

Shin played hane, Fan dodged so Shin took some profit on the right side, and Fan developed the top side even more and got sente. But the profit isn't even that much, black can still cut at a later and then b cut isn't a ladder anymore. Would Cho Chikun the invade/reduce at k16 anyway? With this sequence Elf v1 said Shin went from 63% to 16%.

$$Wc Fan Tingyu (black) vs Shin Minjun
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . O . |
$$ | . . . X . . . . . . . . . . X O O X . |
$$ | . . O . . X . . . . X . . O X O X X O |
$$ | . . . O . . . . . , . . . . X X O O . |
$$ | . . . . X . . . . . . . . 6 . 1 . . . |
$$ | . . O . . . . . . . . . . 4 3 a X . . |
$$ | . . . 0 . . . . . . . . . 8 2 5 9 . . |
$$ | . . . . . . . . . . . . . . 7 b . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . X . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . X O . . . . . O . . . . . X . . . |
$$ | . . X O . X O . . . . . . O . . . . . |
$$ | . . X X O O . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+

Click Here To Show Diagram Code

[go]$$Wc Fan Tingyu (black) vs Shin Minjun
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . O . |
$$ | . . . X . . . . . . . . . . X O O X . |
$$ | . . O . . X . . . . X . . O X O X X O |
$$ | . . . O . . . . . , . . . . X X O O . |
$$ | . . . . X . . . . . . . . 6 . 1 . . . |
$$ | . . O . . . . . . . . . . 4 3 a X . . |
$$ | . . . 0 . . . . . . . . . 8 2 5 9 . . |
$$ | . . . . . . . . . . . . . . 7 b . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . X . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . X O . . . . . O . . . . . X . . . |
$$ | . . X O . X O . . . . . . O . . . . . |
$$ | . . X X O O . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+[/go]

Elfv1's intuition on a few playouts:

Nongshim 3 Fan Shin reduce top.PNG (570.88 KiB) Viewed 15879 times

Update: Shin indeed resigned in early endgame.

[clemi]

FYI, according to sina.com, Fan Tingyu is just 3 victories away from top victory holder Xie He (15 in total) in Nongshim cup for China.

[Uberdude]

Yes, this was some sweet revenge for Fan: 2 years ago he got 7 wins in a row (stopped by Park Junghwan), but then last year he lost the first round to Shin, who then went on to win 5 more (stopped by Dang Yifei who got 5 wins that year). I could see Fan getting several more this year: heavy favourite against the non-Iyama Japanese and >60% vs Iyama if he gets that far, and Lee Sedol is in poor form so favourite there, saving grace for Korea is Choi has a great 7-1 record against Fan (though last was 2015) so if he Choi can bring his top attacking game vs in-form Fan that's my prediction for where his run ends.

[trout]

10/18 3rd game: Fan Tingyu defeated Shin Minjoon by resign.
10/19 4th game: Fan Tingyu vs Katsuya Motoki

Korea:Park Junghwan, Lee Sedol, Choi Cheolhan, Shin Minjoon, Ahn Kukhyun
China:Ke Jie, Shi Yue, Gu Zhihao, Fan Tingyu, Dang Yifei
Japan:Iyama Yuuta, Kyo Kagan, Ichiriki Ryo, Katsuya Motoki, Toramaru Shibano

Bold case - remaining players

[xiayun]

It’s kind of weird to have a Nongshim Cup that misses the top 2 players in the world.

[trout]

Unfortunately, Shin Jinseo was eliminated by Kang Dongyoon during selection tournament.

[macelee]

Mi Yuting was eliminated by Shi Yue during the Chinese qualifying event.

[ez4u]

It’s kind of weird to have a Nongshim Cup that misses the top 2 players in the world.

It is possible to just invite the X top-rated players to each event and get rid of the preliminary tournaments. But if we did that, we would also get rid of the majority of the data that underlies those ratings.

[hyperpape]

Previously:

Japan: 6.5%
Korea: 23.1%
China: 70.4%

Now:

Japan: 5.8%
Korea: 16.5%
China: 77.7%

[Uberdude]

Fan Tingyu beat Motoki Katsuya by resign (was about even on the board and Fan was white). That's it for this month, resumes on 23rd Nov.

[trout]

10/19 4th game: Fan Tingyu defeated Katsuya Motoki by resign.


Korea:Park Junghwan, Lee Sedol, Choi Cheolhan, Shin Minjoon, Ahn Kukhyun
China:Ke Jie, Shi Yue, Gu Zhihao, Fan Tingyu, Dang Yifei
Japan:Iyama Yuuta, Kyo Kagan, Ichiriki Ryo, Katsuya Motoki, Toramaru Shibano

* Bold case - Remaining players

Schedule,

2nd round - 11/23/18
3rd round - 2/19

[trout]

Korea:Park Junghwan, Lee Sedol, Choi Cheolhan, Shin Minjoon, Ahn Kukhyun
China:Ke Jie, Shi Yue, Gu Zhihao, Fan Tingyu, Dang Yifei
Japan:Iyama Yuuta, Kyo Kagan, Ichiriki Ryo, Katsuya Motoki, Toramaru Shibano

* Bold case - Remaining players


Schedule;
11/23/18 Choi Cheolhan vs Fan Tingyu


11/24 - 11/27/18

[Uberdude]

Fan Tingyu beat Choi Cheolhan by resign. According to FineArt on Fox Fan had a sizeable lead from fairly early but Choi managed to make a comeback to almost even in late-middlegame but still lost in the end.