Life In 19x19

Pippen, I think tewari is kind of like a heuristic anyway, so coming up with a counterexample doesn't prove it invalid.

It's just a tool that can be useful for analysis.

Pippen, I honestly don't know what your beef with tewari is (from this and many, many other posts) XD

Tewari is useful in certain situations (when you are able to give reorder sequences reasonably for at least one side), not so useful in others, and can be very easy to misuse if you start giving both sides inferior moves.

I don't know what it would take to persuade you that tewari could be useful, and I guess to be honest it's not that important. Players before Dosaku reached very high levels without really using tewari.

Pippen wrote:Let me try a Tewari-Algorithm: ...:

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.

Dear Pippen,

This is NOT Tewari !!!

I assume that you refer to specification (1) of John's "definition".

This kind of Tewari is NOT simply changing the order of moves only, as you apparently understood.

It is always necessary that you have another position as reference from which you already know whether it is good (= already Jôseki in the original context) or bad (= better for one side). This reference position includes several of the stones placed as in your "new" sequence, but not all, as a matter of course.

After you have identified the "sur-plus" stones of your "new" sequence, you will play these (in an order as "realistic" as possible) to finally create the final position of your "new" sequence. For each exchange of moves you will eveluate whether it was better for one side, or "neutral". Combining the single results will give you your evaluation overall.

+ + + + + + + + + + + + + +

Therefore, you have to ask first, whether the sequence you want to evaluate, is really finished.

If the answer is "Yes", you have to ask yourself second, for your "reference sequence", whether the postion of Black 1, 3, and 5, vs. White 2, 4, and 6, is "Jôseki" (in the sense that neither side has the edge). As a matter of course, you could use the position until White 4 as a master, too, is your answer was "No".

Third step (provided that your answer was "Yes") is to evaluate the pros and cons of Black 7. I.e. asking whether you would like playing this stone elsewhere on the board.

Fourth step is to evaluate the pros and cons of White 8 in the same manner.

Last step is judging the combination of your single results.

Pippen wrote: 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.

$$B
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . 6 . . 7 . . . |
$$ | . . . 4 . . . . . 8 . . . . . 1 . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . 5 . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 2 . . . . . , . . . . . 3 . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+

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:

$$B
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . 8 . . 5 . . . |
$$ | . . . 4 . . . . . 6 . . . . . 1 . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . 7 . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 2 . . . . . , . . . . . 3 . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+

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.

In the reshuffle is bad.

In the reshuffle is bad.

But the even worse Black 5 suggests this is not about go but gomokunarabe. In fact the thread has just been a trolling exercise. We have been mercifully free of these recently and have perhaps let our guard down.

In terms of the usage of "tewari", I've definitely seen it being used outside of joseki situations (usually in fights where a sequence is shown to be a transposed better result of another sequence, showing the other sequence to be a mistake) at least in Chinese commentaries. If the Chinese is happy enough to use tewari in these situations, I don't see why it can't be done in English :p

Bill Spight wrote:
In the reshuffle is bad.

Ok, then put W8 in the lower right corner as a kakari and it's a good move for sure. Then 5 (in the reshuffled board) still looks bad (too small) and therefore 7 in the original would be bad too. Again, I invite anyone to use my algorithm on an example where it's obvious it does not work.

John Fairbairn wrote:

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.

Somebody had better take Kobayashi Satoru aside and let him know he doesn't understand this stuff.
His book on tewari. Theme 10 in chapter 3 where he states that tewari is helpful for fuseki as well as joseki. Actually he introduces 'What is Tewari' at the very beginning of the book with a fuseki example (but it doesn't fit in one photo ).

He introduces tewari to show why we do not block at 2 (instead of 3) in the situation below.

Click Here To Show Diagram Code

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

The tewari analysis starts with the pincer on the board instead of the right side star point. Playing at below would be a poor choice due to the position of

Click Here To Show Diagram Code

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

As should be clear now, powerful descriptions of the usage of tewari as concepts do not come from etymologists and word dictionaries but come from people describing or using the concepts.

Kobayashi's book concentrates on Jôseki, and on application of Jôseki.

Hopefully it is widely known that there are some "middle-game Jôseki" as well.

In his discussions of real games in the final chapter of his book, he uses specification (2) of John's definition, for judging influence, and territory. But even there, he remains connected mainly to Jôseki.

Pippen wrote:

Bill Spight wrote:
In the reshuffle is bad.

Ok, then put W8 in the lower right corner as a kakari and it's a good move for sure. Then 5 (in the reshuffled board) still looks bad (too small) and therefore 7 in the original would be bad too. Again, I invite anyone to use my algorithm on an example where it's obvious it does not work.

But Black played play in response to in the original sequence, which is in the reshuffle. It does not make sense to move that White play elsewhere. One does not use tewari like a lawyer, looking for reasons to justify or attack a certain play.

Kobayashi is right. There is nothing about the tewari heuristic -- not algorithm, thank you -- that restricts its application to any size region of the board. It is a way of detecting inefficiency.

It may be easiest to apply to joseki, because the region is restricted and because there are generally accepted sequences for comparison, but those are practical matters. Broader application does not invalidate tewari.

Cassandra wrote:Kobayashi's book concentrates on Jôseki, and on application of Jôseki.

Hopefully it is widely known that there are some "middle-game Jôseki" as well.

In his discussions of real games in the final chapter of his book, he uses specification (2) of John's definition, for judging influence, and territory. But even there, he remains connected mainly to Jôseki.

Uh , of course? But what do you think the 'application of joseki' is? It is choosing the right joseki to fit the wider aspects of the position. You can be pedantic and insist that this is only about 'joseki' (although I think you must have to close your eyes for some of Kobayashi's diagrams in order to maintain your theory). Good luck with that. The only person you are hurting is yourself.

@Bill: You are right, my alternation didn't make sense, but why is 8 bad in the re-shuffled board? It stabilizes the upper side for White and limits Black's corner which has become bullstrong with 5.

Pippen wrote:@Bill: You are right, my alternation didn't make sense, but why is 8 bad in the re-shuffled board? It stabilizes the upper side for White and limits Black's corner which has become bullstrong with 5.

The answer is hidden in your statement above.

Why do you want to approach thickness ?