Have you ever heard of a thing called "math"? Maybe you should read up on it some time before spouting nonsense.

All fine and well but my comment has referred to SL's statistics with just a few hundred games.

Calling 410 games for 7.5 komi sufficient is the nonsense. Besides the bound 8p+ is arbitrary.

So you are claiming that komi we are using is incorrect and you will prove that?
How arogant....

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I never said it was sufficient, in fact I specifically asked in my post if anyone had a larger sample size. Still, the available evidence does hint at a correct value of 7. Without evidence to the contrary, that is the best current guess we can make.

You standard of evidence, so far, has been "I've heard that". That right up there with "my mother always said" and "I have a gut feeling".

Can you please state if you're talking about area or territory scoring? The correct area scoring komi might be larger than the correct territory scoring komi.

And how do you even define correct? Correct for perfect play? Correct for strong professional level? The komi for 50% winrate might depend on player strength and style. Komi bidding on the other hand circumvents these problems.



Doesn't this imply a komi of around 4.5? Isn't the value of the first move about twice the komi? But you stated the komi should be at least 6.5. Doesn't sound consistent to me.

In the limit of infinitely many moves where the value of moves decreases slowly and steadily the komi is exactly half the value of the first move. But of course that disregards cases with sudden drops in temperature and parity related effects. But I think it should still be around half the move value.

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I will give a pretty convincing reasoning but not a proof.

International Go Rules Forum. Japanese and Chinese were bringing komi statistics, each supporting their preferred komi 6.5 or 7.5 and each, IIRC, based on many pro games. The texts were in Asian languages so I cannot become more precise than "I have heard.". Problem with the statistics was: Included not very many recent games since last komi changes but I think still in the few thousands rather than the few hundreds.

Ing is also said to have done statistics but I have never seen them. So, sorry, only "I have heard.". It is not random input though. Maybe someone can track down those pro game statistics.

In theory this is important, of course. In practice, as long as area scoring uses Standard Area Komi like 7.5, almost all games have the seki parity even and the same winner as under territory scoring. Therefore the statistics are comparable.



Ideally yes.



It depends whether the value of a move is considered with miai counting or deire counting. I use miai counting.



That remark was made in a different context. Read both independently from each other.

Correction. I made a simple counting mistake. It is only 7.9 ~ 8.0 points. The estimate is a sort of lower bound though.

7.0 would definitely be too small. It would be like saying: "With a shimari (2 stones), you make 11 points of territory but its influence is worth only 3 points."

Well, if we plan on using a single komi, then temperature and parity effects don't matter. If there exists a feasible game without these effects, then its komi should be the same as a game WITH those effects

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Under territory scoring the temperature of the empty 3x3 board is 8. That is also proper komi, although the expected komi for a board with temperature 8 (knowing nothing else) is 4. The difference is the result of the huge temperature drop after the first move.

We do not know the temperature of the empty 19x19 board, but, based on a komi of 7, we can guess that it is around 14. Perhaps it is higher, because the four corners can be treated as miai.

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Can you explain why the temperature is 8, is temperature different from the value of a move? If I calculate the value of the move as score-with-that-move minus score-when-passing I get 16. And the same if I use coupons.

When thinking a bit more about the problem I came to the conclusion that since the initial board is invariant under color swapping the correct komi is always half the value of the first move. The sudden temperature drops affect the value of the first move and the komi in the same way.

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Sanity is for the weak.

The value of the empty board is 0, by symmetry. On the 3x3 B1 gains 8 points. That is the temperature, which is how much the largest move gains.

Suppose that there is a board such that the first move gains 8 points, leaving a play that gains 2 points. The game tree looks like this, with / indicating a Black play and \ indicating a White play.



The temperature of the board is 8, the komi is 7. After the first move the temperature drops by 7. The size of the temperature drop does not affect the size of the first play.

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

Visualize whirled peas.

Everything with love. Stay safe.

Why twice the komi value? Are you speaking of local temperature here? This would express the per move value (miai value). I thought that it would be one time the komi value.

Suppose the game would be over after just one play. Since the komi is supposed to be fair, the score must be 0 then. 7 komi points for White versus 7 points for Black gained by the one play. That is, the per move value was 7 points - not 14.

What do I not understand?

Why twice the komi value? There are two extremes. One extreme is that the first play is the last effective play (as with the 3x3 and 5x5 boards). In that case the komi (starting from an empty board) is how much the first play gains (the temperature). The other extreme is that the game is miai, with a score of 0. That leads to an estimate of komi as half the temperature.

Edit:

The error, of course, is rather large. On the 19x19, however, the estimate of the value of sente as one half the temperature is quite good. The main reason is that the temperature drop between plays is normally small. Let us assume that komi is a proportion of the temperature, and that the temperature drop is small. I. e.,

k(t) = s(t) = a*t

The komi when the temperature is t equals the value of sente when the temperature is t, which equals a times t.

k(t0) = t0 - s(t1)

The komi when the temperature is t0 equals t0 minus the value of sente for the new temperature, t1.

a*t0 = t0 - a*t1

By substitution

a*t1 = (1-a)*t0

a/(1-a) = t0/t1

If the drop in temperature is small, then t0 approximately equals t1, and so a/(1-a) approximately equals 1, and so a approximately equals 1/2.

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

Visualize whirled peas.

Everything with love. Stay safe.

Guys, this is the Beginners forum, not Rules