Hi everybody, I've written a little piece about on old idea of mine ("deadweight value of thickness"). Maybe you will find it interesting or contentious.

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A minor point, but if you're going to count Chinese points, you should maybe add a few points to white's territory also (O19,P19,T17).

Yes, you're right. It slipped my attention, but I trust it does not greatly affect the thrust of the argument. But thanks for pointing it out to me anyway.

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Perhaps this will get you more readers:

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Thank you...I feel a bit guilty now for not reading up on how to use the inline game viewer.

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What you seem to be looking for is "current territory" and the "count" (see my books). There is no need to introduce an ambiguous alternative concept "deadweight value".



(The move numbers in the SGF start recounting after the first 14 moves. The L19 SGF interpretation does not handle this correctly. To see correct relation of comments and move numbers, save as SGF and view locally.)

Thank you for sharing you example. It looks like we are talking about the same issue, although our ways of tackling it are different.

BTW, I first wrote a page on SL about "deadweight value of thickness" ten years ago. I would certainly concede that your word "count" is more compact than mine, but possibly mine has its own advantage in expressing the inherent ability of thickness to generate points without any particular further effort.

Anyway, I`m not trying to compete with you; I only thought I would share my own thoughts with the readers here. If by some chance they were to go on to prefer using a Tamiism to one of your terms, that would be beyond your control and mine. Just as we are free to introduce our ideas, others are free to reject them or modify them as they please.

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"count" is a well known term in endgame theory; I have just applied it less strictly to opening and middle game. You can also find a definition of "current territory" here:

http://senseis.xmp.net/?CurrentTerritory



You should be trying to compete because you will have difficulties to justify your values 8 points for White and 19-20 points for Black:)

As emeraldemon pointed out, I probably undercounted White's score, and I accept that. I would up it to 10 in light of his comment. I think 19-20 remains a reasonable assessment of Black's deadweight value on an open board.

A problem I have with your example is that in order to make the "count", you have to surround the wall with white approach moves, but you are not including their value in your calculation. My method seems simpler and not affected by that complication.

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Learn the "tea-stealing" tesuji! Cho Chikun demonstrates here:

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The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

The purpose of "current territory" is to assess ONLY territory of ONLY one player - not to assess newly gained influence of reduction stones.



My method is simpler because the complication of trying to assess influence of newly played reduction stones is not considered at all. Consider your rough idea of extensions and checking extensions. The opposing checking extensions can have a lot of influence. If you wanted to include that, then Bill's objection applies: easily you can get NEGATIVE total values.

Applying n-territory (0-territory is the current territory), the black wall can get a slightly higher territory value; if we determined also its 1- and 2-territory (1-territory: 1 extra black play, extra intersections count 50%, 2-territory: then second extra black play, then extra intersections count 25%), then we enter about your intuitive 19-20 points range (if we still ignore all the white reduction plays / checking extensions). And we get such values due to a clear definition while "deadweight value" remains ambiguous.

Thanks for your input, too, Bill.

I suppose I have come up with a primitive method for assessing wall vs territory exchanges.

Basically, fill in the territory leaving two eyes and that will be the score for the territory side.

As for the influence side, add one for every outward-facing liberty. The influence side should expect to keep control of those points if nothing else. Add half the value again, and then add half the value once more. This is to acknowledge the wall`s affect radiating over the board.

Anyway, maybe estimates produced this way are somewhat conservative, but that's about the size of it: assume a wall will definitely gain profit equivalent to the number of points immediately next door, and then add some more to account for its long-range effect.

In any case, this method shows that influence versus territory exchanges on open boards tend to favour the influence side.

To Robert - your latest post appeared while I was writing this. Please don`t think that I am ignoring you - let me think about your remarks and respond later if I can think of something to add or question.

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Learn the "tea-stealing" tesuji! Cho Chikun demonstrates here:

Bill, you better add that the 14 points value refer to the average local move value aka miai value:) Otherwise people wonder: "Which kind of value?" Your guessed 18 points refer to a different kind of value than the one I have calculated; the two values are not comparable.

What you are saying with "about 18 points" is that Black has gained 4 points by replacing his initial one excess stone worth 14 points by the guessed 18 points miai value. The exact size of "18" is unknown so far and I cannot provide a method yet with which a rather accurate miai value could be determined for the excess stone at the end of the 3-3 under 4-4 invasion.

I can determine current territory, with some more effort probably also n-territory (2 steps iteration) and an approximative territory efficiency. For the miai value, however, more research is necessary, I think.

I have noticed our simultaneous writing and so also edited my post again. No problem:)

I am not referring to move value but the value of the position. True, it is an estimated value.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

Early during the game, there is a close relation though between value of a position, average move value and value of an excess stone. So close that it can be confusing.

I am not sure though that you really mean "value of a position". Don't you rather mean "value of the situation" (taking into account that White has the next turn)? Otherwise I'd add half the average move value (7 points) to your presumed guess of 18 points!

Taking into account who has the move (White), I'd guess 11 points. Taking into account komi of 6.5 or 7.5, I'd guess 4 points.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

18 - 11 = 7, so much I understand. But I don't get it why 11, when I think 18. Can you please explain it?

This early in the game, I think that having the move is still worth around 7 points. It is White's move, so we subtract 7 from 18.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

Ok, now understand, I think... Thank you for trying it with your utterly clear explanation!