Hi Robert,
I comment on some of the points you make, just for flavor, but my main content is on the bottom, in the PS - so unless you find my intermediate comments of great value, I suggest we just restrict the discussion to the two main contention points I make on the bottom of my post. Otherwise the thread deteriorates to sentence-by-sentence discussion which might just dilute what's important. Especially since my PS pretty much just reiterates the rest of my post, which can simply be seen as an extension of the points I make in the PS.
RobertJasiek wrote:Bantari wrote:On an empty board with only 3-3 stone, the extension might not be very forced - there are certainly bigger moves elsewhere.
Good objection, except that you might actually be wrong: if the game starts 3-3, kakari, tenuki, pressing lets the 3-3 sacrifice look bad, IMO.
I dunno... the 3-3 will not be dead after two white moves, and Black will get two moves elsewhere. If White wants to kill the 3-3 he would need to add another stone, which will allow Black to play elsewhere for the 3rd time! This might or might not outweigh the loss of a corner, depending on where the Black moves would be.
This is usually, among other things, why White does not approach the corner on move 2 - it is too small and might not be not sente. Thus the answer might not be forced.
RobertJasiek wrote:Supposing good timing for the kakari, and we can assume that White finds some some timing, surely Black must answer. In an actual game, Black can choose his answer from extension and pincer. In current territory PJ theory, Black answers peacefully; this is the extension.
Timing assumes 2 things:
- other shapes on the board, in which case White approach will surely not be worth 0 points, and
- the timing (and side) is chosen by White, wich would also assume that the approach stone has a better value for White than to make Black 3-3 stone stronger.
So I am not sure how you can claim things like 'timing' on White's part and the point value of White's move to be 0. The assumption of 'timing' itself has to imply the value of White approach to be non-zero or White would never have played there.
RobertJasiek wrote:
the three stones on empty board, you might think that your evaluation seems to be spot on. However - this is a very unrealistic scenario.
It is unrealistic, because you require the first imagined timing. Theory of privileges is more generous to allow some suitable timing.
But then, as said above, the timing should also apply to White's privilege, especially since it is White who picks the time here. You seem to be applying it only to Black's advantage. I understand 'idealizing' a scenario for argument's sake, but I think this is too one-sided.
RobertJasiek wrote:
the White stone has to be counted for at least 2 points - after all, White will not let it die, so eventually it *will* end up with at least 2 1-point eyes.
Nope. You make a mistake here: Black would be attacking and gain more extra points than the 2 one-point eyes of White's group. White would be generating negative territory. Let us be more generous and assume 0 points for the white stone!
I think you make a mistake here.
It stands to reason that each White move will balance the Black move more or less (we do not know to what extend unless we know the outside shapes and the exact timing.) And it also stands to reason that eventually White can count on ending up with more (much more?) then only two points out of this stone. I was being generous for Black here.
In any case - this is not really my major objection to what you say.
Generally speaking, I can't get over two issues here:
- as mentioned before, the approach is played at White's timing, so it cannot only favor Black, and
- as mentioned before, you seem to be assuming existence and then non-existence of outside shapes, willy-nilly as it suits you.
To me, logically and realistically, we have to say that:
- either unspecified outside shapes exist, in which case we simply do not know the value of White approach, but assuming White is half-way competent it will surely be more 0 points. With half-way good timing and direction sense, it might even be more than the added value of Black extension,
- or no unspecified outside shapes exist, in which case there is no way White will play the approach on move 2 but take another empty corner which is larger, and wait for proper timing (i.e. unspecified outside shapes) to make the approach - which brings us to the 'either'-part.
RobertJasiek wrote:
can't they be taken a step further to make even more exact calculations? [...] one could argue that it is now White's privilege to either extend from his approach stone (thus making points [...] I consider it exactly as likely for Black to extend after the White approach as it is for White to *then* extend after Black extension. [...] I see no reason to arbitrarily stop calculating future privileges after Black's first move...
Iterated PJ would become a proceeded game or like endgame calculations. The advantage of PJ to be fast would be lost entirely.
Sure, I said so too, but why not at least apply the method to the whole logical and natural local sequence?
Black 3-3, White approach, Black extend, White extend, Black tenuki, White tenuki. Seems like the count should be applied to *this* position, not at some arbitrary intermediate point. I don't think you have addressed that yet.
When I look at the end of the natural sequence described above, I see Black 8 points, White 4 points, net value 4 points - which might be a good number to give the initial Black move.
___________
PS>
So, to summarize, and give more focus to the discussion, my main points of contention are:
Point #1. The whole outside shapes and timing paradox:
You seem to require the outside shapes for timing to claim forcefulness (as in 'White choses the timing to make Black extension forced') but then deny the outside shapes to dismiss the point value of White approach ('the point value of White approach is zero or even less.') It seems to me that, idealized or not, we should at least be consistent and say that either outside shapes and timing and forcefulness are relevant concepts here, or they are not - and then stick to what we decided. Whatever we decide, though: either White approach is silly and Black extension not forced, or the value of White approach is more than 0 points. One of these positions should be the start of any reasonable analysis of the (partial?) position, I say.
Point #2. The completeness of the sequence:
I don't see how you can decide to calculate points value in the middle of a natural sequence, claiming some moves are forced (Black extension) while others are not (subsequent White extension) with very little, if any justification. It is my feeling that this arbitrariness can create a lot of confusion, if not in this particular example (where the natural sequence is like 2-4 moves long, depending when you start looking) then surely in other cases where natural sequences are much longer. The position needs to be evaluated at the end or such sequences to be useful not at some arbitrary intermediate points to force a specific numerical value.
It seems to me that you are trying to adjust the facts to fit the theory instead of doing it the right way.