how much is a stone worth?

[djhbrown]

Unusually, the BBC has broadcast an interesting program, one which may resonate with you as it did with me.

https://www.youtube.com/watch?v=LAz10MRfM5A

Boltzmann was wrong - there are two or three counterexamples to his theory, which works fine for a cup of coffee, so long as you don't drink it:
1. is our own solar system, which moved from a state of disorder to one of order, even if it's headed towards a new disorder, what with Brexit and the sun dying and all that sort of thing
2. is life itself, which arranges atoms and molecules into cooperative systems, even if they later fall apart, as my own molecules are busy doing - but then along come some anaerobic bacteria and the whole thing starts again, even if within the confines of a cylinder of a Toyota Avalon or an MGB, which if i'm honest with myself, is what i'd rather drive except its boot isn't big enough for my electric trolley although i guess i could just about balance the foamy on its roof, so long as i keep to under 20kph to stop it flapping itself to bits - although, tethers on the bumpers might help that. mmm, worth a try... besides, who needs 14? - i do just as well with 3, and sometimes even just two as i can sometimes putt better with a 7-iron than a Ping.
3. is the value of a Go stone, which starts off pretty high - maybe around 10, and then climbs as high as 14, until it plummets back down to 0.4, and thence to zero when there are no more valuable moves and the game is over... Until, the clock is reset and the next Universe begins when Ke Jie bangs a stone down in Shanghai or wherever the hell it is, somewhere near the pretty Yellow Mountains, where, in a crocodile on the top of a ridge, you can see across a chasm another crocodile on top of another ridge a few hundred years away. Quite an amazing sight.

Item 3 brings us to temperature, which starts off cool as a cucumber with nothing but a dull flat plane, until things heat up with hotspots all over the place, which flip into iciness at the flop of an atari, ultimately ending up in just one of two states - black or white - a binary New World Order that Right-thinking bwankers don't just idly dream of, but spend their whole lives for generations dreaming up new tesuji and trick moves, such as virtual aeroplanes, ransom viruses, false-flag insurgencies and oversupplying the market to undermine Chavez.
https://www.youtube.com/watch?v=VKqCknC ... 9E&index=8

[John Fairbairn]

Komi is worth approximately half a stone.

Bill: You often see commentaries which say something like Black is ahead by the komi. But I saw a new (for me) twist this week when Yoda said White was ahead by about "half a move" (半手).

I knew about the term in theory, in the form of 半手損, but I have never before seen an example in the wild. I have inferred that the term is due to the predilection of pros to count in terms of inefficiencies rather than territories, but in context Yoda may have used it because it was a no-komi game. The final result of a game where he praised both players for superb subsequent boundary play was W+3.

[Tokumoto]

About the numerical value of Sente, I learned from Myungwan Kim that "The difference in value of the biggest move and the next is the value of Sente".

This was mentioned in his commentary with Andrew Jackson on Lee Sedol vs Ke Jie 2015 Samsung Cup semifinals https://www.youtube.com/watch?v=quOHkhwBHWg (32 minutes in)

This is not much useful in fuseki, but thought I'd mention it

[Bill Spight]

Komi is worth approximately half a stone.

Bill: You often see commentaries which say something like Black is ahead by the komi. But I saw a new (for me) twist this week when Yoda said White was ahead by about "half a move" (半手).

I knew about the term in theory, in the form of 半手損, but I have never before seen an example in the wild.

In the opening I have estimated positions in terms of stones (moves) and half stones for ages. I think I have seen Uberdude do the same, BTW.

I have inferred that the term is due to the predilection of pros to count in terms of inefficiencies rather than territories,

It seems quite natural when you think in terms of tewari. I also think that it is appropriate for the opening, given the uncertainty of estimation.

but in context Yoda may have used it because it was a no-komi game.

Well, if there is no komi, why talk in terms of komi?

The final result of a game where he praised both players for superb subsequent boundary play was W+3.

[Bill Spight]

About the numerical value of Sente, I learned from Myungwan Kim that "The difference in value of the biggest move and the next is the value of Sente".

This was mentioned in his commentary with Andrew Jackson on Lee Sedol vs Ke Jie 2015 Samsung Cup semifinals https://www.youtube.com/watch?v=quOHkhwBHWg (32 minutes in)

This is not much useful in fuseki, but thought I'd mention it

Thanks.

From the discussion, it sounds like Jackson is describing the swing value of the largest play. He says, more or less, "If the largest move has these two options, 20 on the one hand and 0 on the other, then the value of sente is the difference between the two, or 20 points." That is different from what we have been talking about, which is the difference between the static value of the current position and the final score for the player who has sente, IOW, how much having sente gains.

For instance, given correct play, our best estimate for the final score on the board, starting from an empty board, is about 7 points for Black. And that is why we have komis of 6.5 and 7.5. Komi is an estimate of the value of sente. We can also estimate the swing value of the first move as being in the range of 25 -30 points. I suppose that would be Kim's estimate for the value of sente. That fits with a value of around 20 pts. in the position Kim and Jackson are talking about. That would correspond to an estimate of about 5 pts., by comparison with komi.

[gowan]

As for the OP question, can we estimate the value of handicap stones using change in reverse komi? There have been experiments in which rather than giving the weaker player handicap stone, instead Black receives a reverse komi. For example, if we know the proper reverse komi for Black instead of placing two stones we could understand the value of thesecond handicap stone.

[John Fairbairn]

In the opening I have estimated positions in terms of stones (moves) and half stones for ages. I think I have seen Uberdude do the same, BTW.

Bill: To clarity: Yoda was doing this about two-thirds of the way through the game.

[Bill Spight]

In the opening I have estimated positions in terms of stones (moves) and half stones for ages. I think I have seen Uberdude do the same, BTW.

Bill: To clarity: Yoda was doing this about two-thirds of the way through the game.

So did he mean around 7 pts., or something else? {shrug}

[Bill Spight]

As for the OP question, can we estimate the value of handicap stones using change in reverse komi? There have been experiments in which rather than giving the weaker player handicap stone, instead Black receives a reverse komi. For example, if we know the proper reverse komi for Black instead of placing two stones we could understand the value of the second handicap stone.

OC, we have to qualify that for the strengths of the players. I once gave a handicap of 40 stones, and the game was fairly close. IIRC, I won by 10 pts. But I could never give a reverse komi of 400 pts. The value of the second handicap stone might be about 14 pts. for a pro, about 12 pts. for an amateur shodan, and about 10 pts. for a 10 kyu., to make a guess.

[djhbrown]

objection! Your Honour, i am neither Original nor a Poster-child for any sect with its own definition of komi, which the great Lord who knows all has decided to be 10, not 7, and most certainly not a fraction of a bit because there's no such thing - and anyone so overlordly as to offer 40 stones deserves to be given 40 lashes and have to spend 40 days and 40 nights in the desert and be burned at the stake for impudence and forfeit the game henceforth and thereafter for ever more shall be, amen.

i challenge you, mighty Billy, to a game in which you will receive a handicap of 360 stones whether you like it or not, and see how that feels...

PS Alfie may be a Bonny Prince, but Myungwan is the rightful heir to the throne of Sage, and what mr K (or was it Tuamoto, can't remember atoll now, and Big Brother wont let me scroll back to check) says he says about sente is, which i also heard him say somewhere else, like everything he says about anything, spot on, including in the fuseki, which is why it's going into Swim, although, having since looked at that video, she will paraphrase Andrew's explanation as: "the difference between playing there and not playing there" without waving her hands in the air