Tewari analysis

Pippen · Post by **Pippen** » Fri May 22, 2015 6:25 pm

I wanna know how one would analyze this Fuseki with Tewari. Can one give a step-by-step description? I still dunno how exactly it works.

Click Here To Show Diagram Code: [go]$$B $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . 3 . . 1 . . . 2 6 . . . . | $$ | . . . O . . . . . , . . . 5 . , O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . 4 . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . X . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]

Bill Spight · Post by **Bill Spight** » Fri May 22, 2015 9:40 pm

In this case I would just permute the moves:

Click Here To Show Diagram Code: [go]$$B $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . 3 . . 5 . . . 6 2 . . . . | $$ | . . . O . . . . . , . . . 1 . , O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . 4 . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . X . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]

Then you can compare it with other sequences, such as

Click Here To Show Diagram Code: [go]$$B $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . 5 . . . . . . . . . . . . . . . | $$ | . . 6 . . 3 . . 7 . . . . 8 2 . . . . | $$ | . . . O . . . . . , . . . 1 . , O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . 4 . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . X . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]

In this case am not sure that that gains much of anything at the amatuer dan level, though.

John Fairbairn · Post by **John Fairbairn** » Sat May 23, 2015 12:39 am

I wanna know how one would analyze this Fuseki with Tewari. Can one give a step-by-step description? I still dunno how exactly it works.

That's probably because tewari (dissection of moves, aka ishiwari) is not really intended for fuseki. It's mainly a joseki tool.

There are two separate modes of analysis: (1) try changing the move order to see whether you would have ended up making a different choice if you have had that freedom in actual play - if so, that hints at inefficiency in your actual choice; (2) remove an equal number of surplus stones for each side and see whether, after that, one side has any "silly" stones still there.

This is the Japanese version. There are snake-oil vendors of other versions.

RobertJasiek · Post by **RobertJasiek** » Sat May 23, 2015 5:05 am

John Fairbairn wrote:snake-oil vendors of other versions.

Also other forms of tewari are meaningful and useful (although hardly for the OP position) and therefore no "snake-oil".

Cassandra · Post by **Cassandra** » Sat May 23, 2015 6:54 am

RobertJasiek wrote:Also other forms of tewari are meaningful and useful (although hardly for the OP position) and therefore no "snake-oil".

Better use another technical term then ?

As John pointed out, 手割り (tewari) is for usage in 定石 (jôseki) only.

RobertJasiek · Post by **RobertJasiek** » Sat May 23, 2015 10:08 am

Cassandra wrote:(tewari) is for usage in 定石 (jôseki) only.

There is no need to restrict it to joseki.

Cassandra · Post by **Cassandra** » Sat May 23, 2015 10:53 am

RobertJasiek wrote:
Cassandra wrote:(tewari) is for usage in 定石 (jôseki) only.
There is no need to restrict it to joseki.

This might be true for the underlying technical concept of "reverse engineering".

However, in every Japanese Dictionary of Go terms that I own, the term "手割り" (TEWARI) is strictly restricted to JÔSEKI. Other
used cases are NOT mentioned at all.

I would like to suggest an application of what King Philip of Macedonia once told his heir:

"My son, ask for thyself another Kingdom, for what which I leave is too small for thee."

RobertJasiek · Post by **RobertJasiek** » Sat May 23, 2015 11:04 am

If the dictionaries dictate unnecessarily restricted application of go theory under the name of tewari, it is time to abandon the Japanese name, speak of "methods for stone, move and shape analysis" and apply the theory without artificial restriction.

SoDesuNe · Post by **SoDesuNe** » Sat May 23, 2015 11:57 am

RobertJasiek wrote:If the dictionaries dictate unnecessarily restricted application of go theory under the name of tewari, it is time to abandon the Japanese name, speak of "methods for stone, move and shape analysis" and apply the theory without artificial restriction.

That's exactly what has been asked: Don't use the term Tewari for non-Joseki-sequences : D

topazg · Post by **topazg** » Sat May 23, 2015 12:03 pm

RobertJasiek wrote:... speak of "methods for stone, move and shape analysis" and ....

Catchy ...

Pippen · Post by **Pippen** » Sat May 23, 2015 2:25 pm

John Fairbairn wrote:(1) try changing the move order to see whether you would have ended up making a different choice if you have had that freedom in actual play - if so, that hints at inefficiency in your actual choice;

Let me try a Tewari-Algorithm: out of what you suggested:

1. Original position of stones
2. Re-shuffle move order of 1.
3. If a move in 2. looks misplaced (despite good plays from opponent) then this move in 1. was not a good one.

Example:

1. Original position, interesting stone: 7.

Click Here To Show Diagram Code: [go]$$B $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . 6 . . 7 . . . | $$ | . . . 4 . . . . . 8 . . . . . 1 . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . 5 . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . 2 . . . . . , . . . . . 3 . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]

2. We re-shuffle the move order and give 7 a new number:

Click Here To Show Diagram Code: [go]$$B $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . 8 . . 5 . . . | $$ | . . . 4 . . . . . 6 . . . . . 1 . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . 7 . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . 2 . . . . . , . . . . . 3 . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]

3. In the re-shuffle 5 is not good because too small, White plays all moves alright (no double bad plays which equalize) therefore the original stone 7 was a mistake.

What do you think? I'd like to have a theoretical algorithm of tewari where every dummy just follow the rules and comes to a conclusion. Because then we could really check if Tewari is for real. Maybe someone can already try to refute my algorithm-attempt with an example?

Bantari · Post by **Bantari** » Sat May 23, 2015 2:53 pm

SoDesuNe wrote:
RobertJasiek wrote:If the dictionaries dictate unnecessarily restricted application of go theory under the name of tewari, it is time to abandon the Japanese name, speak of "methods for stone, move and shape analysis" and apply the theory without artificial restriction.
That's exactly what has been asked: Don't use the term Tewari for non-Joseki-sequences : D

So what is it called? Or do they not analyse anything else than joseki in Japan this way?
I mean - if you perform exactly the same analysis as tewari for non-joeski sequence, with exactly the same methodology, what is it called? Or is such analysis invalid?

It seems to me that if we *can* analyse non-joseki positions like that, it makes more sense to loosen the definition and still call it "tewari" than to come up with yet another foreign-sounding (or convoluted) term. Not to metion that I have seen analyses of non-joseki sequences even in this ng which were still called "tewari" and nobody objected.

Or we can just loosen up the definition of "joseki".

John Fairbairn · Post by **John Fairbairn** » Sat May 23, 2015 2:58 pm

What do you think? I'd like to have a theoretical algorithm of tewari where every dummy just follow the rules and comes to a conclusion. Because then we could really check if Tewari is for real.

Here's an algorithm you might like to try first:

1. Read what was written.

2. Did it say it referred mainly to joseki?

- If NO, exit

- If YES

-- Is the test position a joseki?

-- If NO, exit

-- If YES, try tewari.

I translated a series by Takagawa on tewari in Go World if you want something in English, but there are many articles in the oriental languages, and also in-line comments in very many commentaries. It's not a magic bullet. You apply it as a verification when you suspect something is wrong, or are just plain unsure. It is probably also a matter of taste of how you apply it. My impression is that Also, of the two main methods that exist, the reshuffle one is perhaps the more popular one but the bark-stripping method is considered more reliable (it is used especially with thickness versus territory josekis)..

Pippen · Post by **Pippen** » Sat May 23, 2015 3:16 pm

I still think tewari can be applied for joseki, fuseki and even in middle game. Why not? Again: I invite Go-players to give an example based on my algorithm where my algorithm comes to the cocnlusion the move was bad/good when indeed it was good/bad and hence proves it unreliable.

SoDesuNe · Post by **SoDesuNe** » Sat May 23, 2015 4:13 pm

Bantari wrote:
SoDesuNe wrote:
RobertJasiek wrote:If the dictionaries dictate unnecessarily restricted application of go theory under the name of tewari, it is time to abandon the Japanese name, speak of "methods for stone, move and shape analysis" and apply the theory without artificial restriction.
That's exactly what has been asked: Don't use the term Tewari for non-Joseki-sequences : D
So what is it called? Or do they not analyse anything else than joseki in Japan this way?
I mean - if you perform exactly the same analysis as tewari for non-joeski sequence, with exactly the same methodology, what is it called? Or is such analysis invalid?

It seems to me that if we *can* analyse non-joseki positions like that, it makes more sense to loosen the definition and still call it "tewari" than to come up with yet another foreign-sounding (or convoluted) term. Not to metion that I have seen analyses of non-joseki sequences even in this ng which were still called "tewari" and nobody objected.

Or we can just loosen up the definition of "joseki". ;)

I'm not really the person to ask since I neither speak (or read sufficiently) any oriental language nor did I really use Tewari, but I guess my answer would be to look up oriental (in this example most likely japanese) literature about it - the source so to speak.

By the way, I assume it is highly possible that Tewari was/is used out of the original japanese context and nobody objects. But this bears the question: Who can actually object?
It's a japanese concept. Unless you read it up at the source, you can just take the name and do whatever with it. If the result is any good, when some non-oriental amateurs do so, well...

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