Life In 19x19

Aja Huang post

Yesterday in his game against Ke Jie 9p, Park Junghwan 9p played White move 10. Indeed AlphaGo likes the move. AlphaGo would play Q16 even before R6 hane. I appreciate the way professional players are exploring new ideas. Go is exciting with their adventurous exploration.

Bill Spight wrote:

dhu163 wrote:215 losing move. Deepzen's endgame ... this loses 1 point compared to S1. As it loses sente. After top is played, after S1, W must play A4, and B gets Q1 for B4 in sente, and then B wins by playing the only move L19 so that B still gets the last endgame. Most amateur players would miss this mistake.

215: R-01 is a losing sente, losing 3/4 pt. from the original position. So it is the obvious suspect.

Also, Black 231, S-01 instead of A-03, sacrifices 1/6 pt. by allowing White A-04, in order to get B-05, which gains 2 pts. (White has sacrificed 3/4 + 1/6 = 11/12 pt. in these maneuvers! ) By contrast, the alternative sequence given above lets White get B-05 and gain 2 pts. The swing is 4 pts. in the bottom left. However, the swing in the bottom right is also 4 pts., for a wash in the two regions. The difference is who plays first (and last) at temperature 1. In the game it was White, in the alternative sequence it is Black. There is your 1 pt. difference.

Sorry, folks, my mistake. Black can get the last play at temperature 1 in either sequence. And Zen actually did in the game (Black 245). All I had to do was look at the game record. That means that Black B-05 in the game is the effective last play, and it gains 2 points, not 1! Well done, Zen!

Gaining 2 pts. with the last play is unusual, and the actual game sequence is 1 pt. better for Black than the alternative sequence. Sacrificing 11/12 pt. to gain 1 pt. may not be enough to swing the game, but it is hardly an error. OC, we do not have a full endgame analysis from move 215, so Zen may have erred, but, based on what I have seen so far, probably not.

For my analysis of the play on the top half of the board at temperature 1, see forum/viewtopic.php?p=222247#p222247 .

After crashing out of LG Cup, Korean players will have their best opportunity to win a title this year here, as both Parks should be favored against the two young Chinese players (even though Li Xuanhao actually has a higher GoRating than Yeonghun at the moment). The Best-of-3 semifinal matches will be played on 17th, 19th, and 21st:

Park Junghwan vs. Xie Ke
Park Yeonghun vs. Li Xuanhao

Round 1:
Park Junghwan vs. Xie Ke
Park Yeonghun vs. Li Xuanhao

Park Junghwan shoulder hit Xie's 3-3 on move 3 and I wonder if this was a mistake seeing how the game went: for several years now my understanding has been the shoulder hit should be seen as a special purpose joseki rather than a default one against 3-3, only applicable where building your or reducing opponent's moyo is important. This is particularly if you play all 4 moves of the typical joseki and end in gote, if you take sente (as Park did) and can treat it as an efficient probe against which way white pushes that's a redeeming point. In the game Park spend some extra moves to develop the shoulder hit group to the centre, but it wasn't exactly thick and in later fighting Xie resisted Park's attempt to make him connect on dame and just lived in the centre despite Park's influence.

Click Here To Show Diagram Code

[go]$$Bm3 Park (B) vs Xie
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 5 . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 9 . . |
$$ | . . . . . . . . . . . . . . . 0 . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . 8 . . . |
$$ | . . . 3 . . . . . . . . . . . . . . . |
$$ | . . 2 1 . . . . . , . . . . . , 6 . . |
$$ | . . O . . . . . . . . . . . 7 . . . . |
$$ | . . . . 4 . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+[/go]

Park Junghwan took an early lead, and Xie Ke kept playing questionable moves one after another, and by move 100, the game was basically over.

But then, Park screwed up big time, and gave Xie Ke a chance. Xie Ke took it, and ended up reversing the game for a slight lead, forcing Park to resign.

I really have to share this comment from sina... My translation doesn't do the original comment justice, but it will have to do...

"For many years, Park Junghwan has been quietly and tirelessly shedding sweat and tears, working towards the growth and providing opportunity for promising young Chinese players. From Ke Jie to Fan Tingyu to Tang Weixing... Park often destroys the walls of his own home (i.e eliminate other top Korean players) for the noble mission of supporting international Go, particularly for Chinese Go, he spares no effort in adding bricks to its foundation. Park is truly a great warrior fighting for internationalism!

Little Xie, if even after giving you so much help and support to help you climb up you still can't do it, the person you should be sorry to is not yourself or go fans, but Park Junghwan!"

What was Park's big mistake? When I started watching (around move 120) it felt like Xie was cheekily taking cash whilst living everywhere as Park was trying to pick up some profit from hassling him but not getting much, though I didn't actually count if he had enough.

With the Ke vs Iyama match in the LG cup I compiled a little list of how far they got in recent international tournaments (see bottom), so I thought I'd do the same for Park.
- 8th Ing (2016): lost to Tang Weixing in final
- 21st Samsung (2016): lost to Fan Yunruo in quarter final
- 22nd Samsung (2017): lost to Gu Zihao in quarter final
- 21st LG (2016): lost to Zhou Ruiyang in semi final
- 22nd LG (2017, this one): lost to Jiang Weijie in round of 16
- 2nd MLily (2015/6): lost to Zhou Ruiyang in round of 16
- 3rd MLily (2017/18): 1-0 down to Xie Ke in semi final
- 3rd Bailing (2016): lost to Chen Yaoye in quarter final
- 11th Chunlan (2016/7): lost to Mi Yuting in round of 16
- 1st Xinao (2016/7): lost to Peng Quan in round of 64

Semi-finals: 3, finals: 1 (and potentially 1 more if wins next 2 games agaisnt Xie), wins: 0 (potentially 1). Notable that he only loses to Chinese players.

Ke Jie in last 2 years of international tournaments:
- 8th Ing (2016): lost to Park Junghwan in quarter finals
- 21st Samsung (2016): won
- 22nd Samsung (2017): lost to An Sungjoon in round of 16
- 21st LG (2016): lost to Park Junghwan in round of 16
- 22nd LG (2017, this one): lost to Iyama Yuta in semi finals
- 2nd MLily (2015/6): won
- 3rd MLily (2017/18): lost to Park Junghwan in round of 16 (noticing a theme?!)
- 3rd Bailing (2016): lost to Chen Yaoye in final
- 11th Chunlan (2016/7): lost to Park Yeonghun in semi final
- 1st Xinao (2016/7): in final

So in semi-final of 6 of 10, final of 4, won 2 and 1 final still to play.

Iyama plays much fewer international tournaments, only 2 of that set of 10:
- 22nd Samsung: lost to Shin Jinseo in round of 16
- 22nd LG: in final

move 111 specifically, but the few moves before that as well, according to Peng Quan. It's inconsistent with his earlier play where he let white off relatively easy at the top; that was fine because black was leading by like 10+ points, but then suddenly he started being super aggressive, playing moves that losses points like 107.

And then in the attack on the center white group, black didn't gain anything at all, so all of the moves that lost points were just lost points for nothing, which reversed the game.

instead of 111, he should have extended the black stone in the middle, forced white to connect up in dame while solidfying his center group and taking the left side, according to Peng Quan.


And ya, that's why Chinese fans love him

Thanks, 107 did puzzle me seeing as it didn't allow a centre kill. Also I wondered if 105 could extend first (I think need to not cut at 101 earlier to save liberty). It did seem sad that after 111 white even managed to rescue the 2 stones later whilst living plus make black need to spend a move on rescuing his shoulder hit group.

Uberdude wrote:Round 1:
Park Junghwan vs. Xie Ke
Park Yeonghun vs. Li Xuanhao

Park Junghwan shoulder hit Xie's 3-3 on move 3 and I wonder if this was a mistake seeing how the game went: for several years now my understanding has been the shoulder hit should be seen as a special purpose joseki rather than a default one against 3-3, only applicable where building your or reducing opponent's moyo is important.

Well, this is how Shusai played against Go Seigen, so there's that.

Let's do a little tewari.

Click Here To Show Diagram Code

[go]$$Bm3 Tewari
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 1 . . . . . . . . . . . . . . . |
$$ | . . 4 3 . . . . . , . . . . . , . . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . 2 . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+[/go]

is plainly bad, but then the exchange, - is better for White. The question, it seems to me, is whether and are heavy. Human play in the 20th century seems to indicate that they are, but it is easy to imagine Master leaving this corner as is and playing elsewhere. White has broken symmetry, so treating Black's play as a probe seems reasonable.

Here is the end position. Notice how white got several dozen points in the lower left and black got precisely zero from his shoulder hit group in that entire quadrant. Sometimes you use influence to make territory elsewhere on the board, but I don't think you can much say this for the left side or top here seeing how white comfortably lived in the middle, perhaps for the 2 dead stones and handful of points just right of centre. So I think Park's group ended up rather useless and inefficient.

Click Here To Show Diagram Code

[go]$$W
$$ +---------------------------------------+
$$ | . . . . . O . O . O X . . . . . . . . |
$$ | . . X X O . O X O X . X . . . . . . . |
$$ | . X . . X O . X X X X . X . X O . . . |
$$ | . . X X X O O . O , O X X . X X O O . |
$$ | . . . . O X O . O O O O X X . . X X X |
$$ | . . . . . X X X X X X O O O O X X O X |
$$ | . . . . . . X . X . O X O O . O O O 1 |
$$ | . X . X X X O X O . O X X O O . . . . |
$$ | X X . X O X O . O O . O X . X O O O . |
$$ | X O O X O O O O . O O O X X . , X . . |
$$ | O . O O X X X X O O . X O X . X . X . |
$$ | . O . O O O O X O . O X O X . X O X . |
$$ | . . X O X X X X . O X X . X . O . O . |
$$ | . O O X X O X X X X . . . . . O O . . |
$$ | . O X X O . O O O X X . X X X . . . . |
$$ | . . O X . O . O . O O X O X O O O . . |
$$ | . . O X . O O . O . O X O O X O . . . |
$$ | . . . O O . . O . . O X . O X . . . . |
$$ | . . . . . . . . . . . . X . O . . . . |
$$ +---------------------------------------+[/go]

Uberdude wrote:Here is the end position. Notice how white got several dozen points in the lower left and black got precisely zero from his shoulder hit group in that entire quadrant. Sometimes you use influence to make territory elsewhere on the board, but I don't think you can much say this for the left side or top here seeing how white comfortably lived in the middle, perhaps for the 2 dead stones and handful of points just right of centre. So I think Park's group ended up rather useless and inefficient.

But, it's probably that formation which makes the cut at 77 so efficient and thus enabling Park to get about even profit at left and top.

for what it's worth, Peng Quan says the 4-4 move is very hard to deal with. It's a move that forces white to choose a direction, so then black can choose which star point to take (either top left or lower right).

Normally, if you take the other corner first then do the 4-4, white will definitely extend in the other direction, because.. it's better direction. But playing the 4-4 now removes that possibility for white. That's the purpose.

Peng Quan thinks that where black went wrong with that group is when black hane'd on top, after white played the knight's move i.e response to white's move 30; black should have hane on the bottom and sabaki. If black hane on the bottom, Peng Quan thinks the position is already good for black.

The shoulder hit as a probe certainly gives a nice flow to the fuseki, and the threat to turn and develop the left side kind of induced white into that extension on left side. So the group could get its profit indirectly by making the opponent play more cautiously, but I still worry that once the dust settles it didn't make much profit.

Peng likes this and treat the two stones lightly? I think I saw Zen do this. A black territory on the lower side looks more likely now.

Click Here To Show Diagram Code

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

actually, no. he says that if you play atari on move 3, then it's pointless.

http://eidogo.com/#vc223f3E

Dunno how to use the diagram thing here.

Thanks, I did wonder about not playing atari but wanted to get both ataris after extend and cut, nice tewari argument about how one is enough with g3.

Btw I make diagrams with http://hiddema.nl/diagrammer/