Tsumego Question

[othkhvn]

I just downloaded 围棋练习大全, a Chinese tesuji, tsumego, and joseki app. On the positive side, there are a lot of problems -- 320 tesuji and 735x3 elementary-/middle-/upper-level life and death problems. On the negative side, I don't think you can see the solution unless you get it (probably better for training). Any inputs on the below?

$$c Black to play. \n Source: 围棋死活练习[初级411/735]
$$ --------------------
$$ . . . . . . . . . . |
$$ . . . O O X O . . . |
$$ . O . O X X . O . . |
$$ , . O X . X , X . . |
$$ . O . X X X . O . . |
$$ . . . X O X O . . . |
$$ . . O . O X O . . . |
$$ . . . . O O O O . . |
$$ . . . . . . X . . . |
$$ , . . . . . , . . . |

Click Here To Show Diagram Code

[go]$$c Black to play. \n Source: 围棋死活练习[初级411/735]
$$ --------------------
$$ . . . . . . . . . . |
$$ . . . O O X O . . . |
$$ . O . O X X . O . . |
$$ , . O X . X , X . . |
$$ . O . X X X . O . . |
$$ . . . X O X O . . . |
$$ . . O . O X O . . . |
$$ . . . . O O O O . . |
$$ . . . . . . X . . . |
$$ , . . . . . , . . . |[/go]

[gonut]

I just downloaded 围棋练习大全, a Chinese tesuji, tsumego, and joseki app. On the positive side, there are a lot of problems -- 320 tesuji and 735x3 elementary-/middle-/upper-level life and death problems. On the negative side, I don't think you can see the solution unless you get it (probably better for training). Any inputs on the below?

$$c Black to play. \n Source: 围棋死活练习[初级411/735]
$$ --------------------
$$ . . . . . . . . . . |
$$ . . . O O X O . . . |
$$ . O . O X X . O . . |
$$ , . O X . X , X . . |
$$ . O . X X X . O . . |
$$ . . . X O X O . . . |
$$ . . O . O X O . . . |
$$ . . . . O O O O . . |
$$ . . . . . . X . . . |
$$ , . . . . . , . . . |

Click Here To Show Diagram Code

[go]$$c Black to play. \n Source: 围棋死活练习[初级411/735]
$$ --------------------
$$ . . . . . . . . . . |
$$ . . . O O X O . . . |
$$ . O . O X X . O . . |
$$ , . O X . X , X . . |
$$ . O . X X X . O . . |
$$ . . . X O X O . . . |
$$ . . O . O X O . . . |
$$ . . . . O O O O . . |
$$ . . . . . . X . . . |
$$ , . . . . . , . . . |[/go]

Probably not a kyu-level problem. The variations are numerous, but one theme begins with the sequence: b-Q19, w-R19, b-Q17, w-R18, b-S17, after which Black still has to play carefully, but seems to be able to reach a ko on Q16-R17 for life.

[EdLee]

First feelings: (a) or (b).
Then, read if each works. If neither works,
then look for another move, but it seems grim.

$$
$$ --------------------
$$ . . . . . . . . . . |
$$ . . . O O X O b . . |
$$ . O . O X X . O . . |
$$ , . O X . X , X a . |
$$ . O . X X X . O . . |
$$ . . . X O X O . . . |
$$ . . O . O X O . . . |
$$ . . . . O O O O . . |
$$ . . . . . . X . . . |
$$ , . . . . . , . . . |

Click Here To Show Diagram Code

[go]$$
$$ --------------------
$$ . . . . . . . . . . |
$$ . . . O O X O b . . |
$$ . O . O X X . O . . |
$$ , . O X . X , X a . |
$$ . O . X X X . O . . |
$$ . . . X O X O . . . |
$$ . . O . O X O . . . |
$$ . . . . O O O O . . |
$$ . . . . . . X . . . |
$$ , . . . . . , . . . |[/go]

[othkhvn]

Appreciate the responses. I could only find this failure path through brute force, so I'm about to chalk it up to an error in the app.

gonut, you're right -- this falls under the "Elementary" problem set and feels far from kyu-level ("Mid-Level" is suggested at 3dan and "Advanced" is for 5dan up). Along those lines, if you have a cursory knowledge of Chinese, there's a wealth of problems here. Appear to be some questions around the quality of the answers though...

[Shaddy]

I'm 4d KGS ~ 7d WBaduk, Tygem ~ weak 5d Chinese and the Elementary set is about right for me. I don't know who made the app but they're awesome.

[gonut]

I've extended what I mentioned above as potentially the correct line. I also added Ed's suggested possibilities as variations. I'm not a strong player, so if anyone can see a flaw, please speak up.

And if this problem is really in the "Elementary" section, then I need to go back to just playing tic-tac-toe.

(;
AB[qd][ob][oc][od][oe][of][og][ne][me][mf][md][nc][pi]
AW[qh][ph][oh][nh][pg][pf][qe][ng][nf][lg][ke][ld][mc][nb][mb][kc][pb][qc]
(;
B[pa]
C[Only option that works for Black?];
W[qa];B[pc]
C[Black seems to need this shape to set up a ko below this point.];
W[qb];B[rc];W[oa]
(;
B[ra];W[rd];B[pe]
C[Best result for both sides? Black has an unfavorable 2 step ko.];
B[pd]
C[Black doesn't seem to have a direct ko? For example ...];
W[rb];B[re];W[sc]
C[Black cannot make the 2nd eye on the edge.]
)
(;
B[re]
C[Fails];
W[rb];B[sb];W[na];B[rg];W[rh]
C[Amazingly, Black cannot seem to make the 2nd eye on the right side.]
(;
B[qf]
C[For example ...];
W[pe];B[pd];W[qg];B[rf];W[sg];B[sf];W[sd]
)
(;
B[pe]
C[No better.];
W[qf];B[rf];W[sg];B[sf];W[sd]
)
)
)
(;
B[qb]
C[Ed Lee's suggestion.];
W[pc]
C[But after this move, how can Black make an eye in the corner or cut off White?];
B[pa];W[rc]
)
(;
B[rd]
C[Ed Lee's suggestion.];
W[oa]
C[But after this move, how does Black make an eye on the side?]
)
(;
B[rc]
C[Looks good, but fails.];
W[rb];B[pc];W[qb];B[re];W[oa];B[pa]
C[Black is aiming for the ko in the corner.];
W[qa]
C[Transposes to an earlier variation, in which Black dies.]
)
)

[EdLee]

And if this problem is really in the "Elementary" section, then I need to go back to just playing tic-tac-toe.

Hi gonut,

No need to go back to TTT; this is probably anywhere from mid-dan up.
Anyone less cannot assess it accurately; you have to find someone at least that level evaluate it.
It takes level to see level.

[tentano]

Always love a title which says "simple elementary basic introduction to beginner's fundamentals" while the content covers mid to high dan stuff.

I'm not sure if this makes go more accessible, though.

[John Fairbairn]

I feel mystified why some people get in such a lather about a virtually non-existent issue.

The original problem collection was devised for a Chinese audience. For all we know it came with a set of textual hints. Each problem possibly was also presented in a graded way built on previous examples. The Chinese title implies these problems are for repetitive practice, so that by the time you repeat them enough they are elementary - that's the idea, surely? After all, many problems only look hard until you know the solution then they seem trivial, as egg-man Columbus reminded us.

As far as this problem set goes it does not appear to claim to be a "How Good Is Your Go?" test. The implied question, a much better one, is "How Good Do You Really Want To Be?"

[Cassandra]

The original problem collection was devised for a Chinese audience. For all we know it came with a set of textual hints. Each problem possibly was also presented in a graded way built on previous examples.

The original classification on the problem collection's website was "chuji" = "Beginner Dan", "zhongji", and "gaoji" = "High Dan".

No textual hints on the website, just the problems alone. Also no "graded" way for "building on previous problems", as to my experience.

However, as far as the problem in the initial posting is concered, according to my experience with solving Tsume-Go, problems that have a Ko as the correct answer are always assessed to be more difficult (especially when it includes another than a "simple direct" Ko) than problems with unconditional answers.

[othkhvn]

Regarding the original problem, I'm a little concerned that the only path I was allowed to click on resulted in the failure.

gonut's Q19 for ko does seems the most promising.

As John Fairbairn wrote, it could very well be that the original source of the problems used in the app had more textual aids. As piracy and not citing sources are common practices in China, it's possible the app makers simply omitted hints and/or the answer from the original source. The app maker isn't solely focused on Go and has apps for Xiangqi, backgammon, Freecell, Mahjong, etc.


Adding to Cassandra's post, the "About" section of the app shows:
初级围棋死活练习(适用初学者) -- Chuji Weiqi Sihuo Lianxi (Shiyong Chuxuezhe)
中级围棋死活练习(业三段左右) -- Zhongji Weiqi Sihuo Lianxi (Ye Sanduan Zuoyou)
高级围棋死活练习(业五段以上) -- Gaoji Weiqi Sihuo Lianxi (Ye Wuduan Yishang)

My interpretation of the translation is:
[Elementary] Level Life & Death Practice (Suitable for Beginning Students)
Middle Level Life & Death Practice (Around [Professional] 3dan)
[Upper Level or Advanced] Life & Death Practice ([Professional] 5dan and up)

I'm having a little trouble translating the dan and whether or not it is Professional or Amateur. Professional in Chinese is 专业 (Zhuanye) and sometimes 职业 (Zhiye). Amateur is 业余 (Yeyu). Of course, the only character we're given is 业 (Ye), which could be the abbreviation of either -- hopefully somebody familiar with Chinese Go/Weiqi terms could help us out. My read from this is that Amateur dan ranks are written with Arabic numerals and Professional dan ranks are written in Chinese characters, which would make these Professional dan ranks.

EDIT: Spoiler added to hide possible first move.

[Cassandra]

I would like to assume that "Dan" is meant as an amateur rank.