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Is a half point komi really fair?
http://www.lifein19x19.com/viewtopic.php?f=11&t=11213		 Page 1 of 3
Author:  Joelnelsonb [ Wed Dec 17, 2014 2:00 pm ]
Post subject:  Is a half point komi really fair?
So I've wondered this ever since I got into Go but at first I just assumed I didn't understand the game enough yet. Well, I certainly have worlds left to learn but I've also made a lot of progress (thanks to most of you, btw) and I still can't figure out how a half point for white is fair. I mean, lets say you give white the 6 points komi for a supposed even game and then gave white the half point for a 6 and a half point total komi in order to avoid draws. Well, basically what you're saying is "in the event of a draw, white wins". Why shouldn't black get the half point? And if you say "well, white moves second", I would say that white has already been compensated for that with komi. So it makes no sense that white should win every draw by default. Furthermore, I don't like the idea of avoiding draws. I believe an occasional draw keeps the game pure. Without draws, you're saying that one side has an advantage that can't be overcome with best play on both sides. In other words, with a perfect game like Chess (bare with me), perfect play on both sides will result in a draw everytime, 100 out of 100. That's because neither side has any advantage (again, bare with me; I don't consider white to have any advantage despite having a slightly better winning percentage). By eliminating draws, you're making it so that black can't win if white plays perfectly (if such a thing is theoretically possible; I believe it's called playing the "Divine Move"...?) Anyways, got to thinking more about it after watching the game in Hikaru No Go between Sai and the Meijin where Sai wins by a half point (sorry for the spoiler).I believe the actual game was played by Rin Kaiho (9 Dan) as black and Yoda Norimoto (9 Dan) as white.
Author:  xed_over [ Wed Dec 17, 2014 2:42 pm ]
Post subject:  Re: Is a half point komi really fair?
Joelnelsonb wrote:
basically what you're saying is "in the event of a draw, white wins".

yes, that's exactly what you're saying.

Joelnelsonb wrote:
I don't like the idea of avoiding draws.

So, don't use the .5 komi.
There's nothing wrong with Jigo (tie).
Author:  Krama [ Wed Dec 17, 2014 2:55 pm ]
Post subject:  Re: Is a half point komi really fair?
Beginners assume that komi is a part of rules of go like capturing or ko..

It is not. You don't have to play with komi if you don't want to (komi doesn't make any difference in beginner games anyway, only when you reach SDK will it mean more but even then the games tend to be chaotic)

You can take a 20 komi, or 20.5 if you want to be sure there will be no draws.

You can even take negative komi if you are playing against someone stronger and you don't want to play vs handicap stones.

Komi is just a way to make the game more balanced and fun, it is not a part of rules.
Author:  Uberdude [ Wed Dec 17, 2014 3:04 pm ]
Post subject:  Re: Is a half point komi really fair?
Joelnelsonb wrote:
I still can't figure out how a half point for white is fair. I mean, lets say you give white the 6 points komi for a supposed even game and then gave white the half point for a 6 and a half point total komi in order to avoid draws. Well, basically what you're saying is "in the event of a draw, white wins". Why shouldn't black get the half point? And if you say "well, white moves second", I would say that white has already been compensated for that with komi. So it makes no sense that white should win every draw by default.


But maybe white got 7 komi and then black got half a point so that black wins draws. :)
Author:  gowan [ Wed Dec 17, 2014 3:17 pm ]
Post subject:  Re: Is a half point komi really fair?
Some reasons that komi was introduced and is still used:

It has been understood for at least 150 years that in go Black has a significant advantage coming from the first move. The komi, an abbreviated Japanese of the word "compensation" borrowed from English, is intended to neutralize the advantage Black has from having the first move. Once professional tournaments begun to play more often, Black's advantage created a problem. One solution was to have each "game" between two players become a two game match with each player playing white in one game and black in the other. This made tournaments more expensive for sponsors and take longer to finish.

See this SL link for more information on komi: http://senseis.xmp.net/?Komi
Author:  emeraldemon [ Wed Dec 17, 2014 4:05 pm ]
Post subject:  Re: Is a half point komi really fair?
I agree that if you want to play with jigo you should play with jigo. Sometimes a tie can feel very rewarding as a player, a hard fought game that almost seems to end in a compromise.

From a tournament point of view, ties make the setup more complex I think. It's dead simple to arrange and understand single-elimination brackets, which seem very common in professional go tournaments. If the game is jigo, who should be eliminated?
Author:  EdLee [ Wed Dec 17, 2014 7:58 pm ]
Post subject: 
Joelnelsonb wrote:
with a perfect game like Chess (bare with me), perfect play on both sides will result in a draw everytime, 100 out of 100.
But this is only your belief, not a proven fact.

Computers have already solved checkers and mancala: yes, they are both draws with perfect play. But not yet for chess or Go -- it's still an open question.
Author:  yoyoma [ Wed Dec 17, 2014 9:35 pm ]
Post subject:  Re: Is a half point komi really fair?
Yes 6.5 komi is 100% unfair.... to either black or white. But I don't know who, maybe there is a 50% chance it's unfair to black and a 50% chance that it's unfair to white.

So that means it's fair. :)
Author:  S2W [ Wed Dec 17, 2014 11:39 pm ]
Post subject:  Re: Is a half point komi really fair?
Fair when I win by 0.5, so very unfair when I loose.
Author:  Cassandra [ Thu Dec 18, 2014 12:52 am ]
Post subject:  Re: Is a half point komi really fair?
As a beginner, there is no need at all to worry about Komi. You will NOT encounter a drawn game as often as you suspect apparently.

In the Berlin Crane's Tournament, they have NO Komi.

This year, 364 games were played in the tournament, with 2 Jigo only.
One of these Jigo appeared in a game between 5d / 4d, the other one between 2k / 3k.
Author:  Sennahoj [ Thu Dec 18, 2014 2:02 am ]
Post subject:  Re: Is a half point komi really fair?
@Edlee, well the situation is not really the same for go and chess. For chess, the question is if perfect play leads to draw. For go the question is what the magnitude of fair komi is (most people agree it is > 0, and yes there is no proof --- but the sign of komi has nothing to do with the half point). I definitely agree with the OP that the half point is unfair --- if B and W both play perfectly, the result should of course be a draw!
Author:  Cassandra [ Thu Dec 18, 2014 2:11 am ]
Post subject:  Re: Is a half point komi really fair?
Sennahoj wrote:
I definitely agree with the OP that the half point is unfair --- if B and W both play perfectly, the result should of course be a draw!

In this case I would like to suggest accepting the half point as a integral part of "Tournament Rules".

As a matter of course, there is really no need to apply this on "private" games.
Author:  EdLee [ Thu Dec 18, 2014 3:08 am ]
Post subject: 
Sennahoj wrote:
there is no proof
if B and W both play perfectly, the result should of course be a draw!
Hi Senn, could you elaborate ? Your 2 statements seem to contradict each other: that there is no proof that perfect play would lead to a draw.
How do you know ?
Author:  HermanHiddema [ Thu Dec 18, 2014 4:42 am ]
Post subject:  Re: Is a half point komi really fair?
Although there is no proof for the correct value of komi, there is proof that it exists and that it is not smaller than 0. The correct komi is well-defined, it is the amount of points by which black wins if both players play perfectly (which may be 0). Given that the definition of correct komi is basically "the amount of compensation white needs to get a draw if both players play perfectly", then obviously, by circular reasoning, with the correct komi perfect play leads to a draw. :)
Author:  Kirby [ Thu Dec 18, 2014 7:05 am ]
Post subject:  Re: Is a half point komi really fair?
HermanHiddema wrote:
Although there is no proof for the correct value of komi, there is proof that it exists and that it is not smaller than 0. The correct komi is well-defined, it is the amount of points by which black wins if both players play perfectly (which may be 0). Given that the definition of correct komi is basically "the amount of compensation white needs to get a draw if both players play perfectly", then obviously, by circular reasoning, with the correct komi perfect play leads to a draw. :)


What was the proof that the correct value of komi is not smaller than zero?
Author:  amatterof [ Thu Dec 18, 2014 7:17 am ]
Post subject:  Re: Is a half point komi really fair?
Kirby wrote:
What was the proof that the correct value of komi is not smaller than zero?


Wouldn't it just be that, if there is any advantage to playing second, Black's first move could be "Pass," and he could recapture that advantage? (Or both players' optimal play is "Pass" and komi really is 0.)
Author:  HermanHiddema [ Thu Dec 18, 2014 8:43 am ]
Post subject:  Re: Is a half point komi really fair?
Kirby wrote:
HermanHiddema wrote:
Although there is no proof for the correct value of komi, there is proof that it exists and that it is not smaller than 0. The correct komi is well-defined, it is the amount of points by which black wins if both players play perfectly (which may be 0). Given that the definition of correct komi is basically "the amount of compensation white needs to get a draw if both players play perfectly", then obviously, by circular reasoning, with the correct komi perfect play leads to a draw. :)


What was the proof that the correct value of komi is not smaller than zero?


If putting a stone on the board would cause black to lose by 1 or more points, he would pass instead, and could then by symmetry achieve the same score against any first move by white. White would therefore also pass, and the score difference would be 0.
Author:  Kirby [ Thu Dec 18, 2014 10:17 am ]
Post subject:  Re: Is a half point komi really fair?
amatterof wrote:
Kirby wrote:
What was the proof that the correct value of komi is not smaller than zero?


Wouldn't it just be that, if there is any advantage to playing second, Black's first move could be "Pass," and he could recapture that advantage? (Or both players' optimal play is "Pass" and komi really is 0.)


HermanHiddema wrote:
If putting a stone on the board would cause black to lose by 1 or more points, he would pass instead, and could then by symmetry achieve the same score against any first move by white. White would therefore also pass, and the score difference would be 0.


Ah yes, of course. I seem to recall having thought about this before, but I had forgotten. Thanks for explaining. :-)
Author:  Bill Spight [ Thu Dec 18, 2014 11:13 am ]
Post subject:  Re: Is a half point komi really fair?
Let us suppose that, with correct play by both players, the result on the go board is 7 points for Black by area scoring. Then, if correct play were known, komi would be 7 and the game would result in a tie. OTOH, if correct play were known, we would not be playing 19x19 go. :)

Given that, what about Button Go, where at his turn a player can take the button, which is worth 1/2 point. In that case we have to consider two possible ways that Black can get 7 points. In one case Black has 6 more points of territory than White and also gets the last dame; then White will take the button, for a final score of 6.5 for Black. In the other case Black has 7 more points of territory than White, White gets the last dame, and then Black takes the button, for a final score of 7.5. Then a komi of 6.5 or 7.5 would be correct, if correct play were known. We can estimate that there would be around half as many ties as without the button.
Author:  Elom [ Thu Dec 18, 2014 11:58 am ]
Post subject:  Re: Is a half point komi really fair?
First of all, we cannot even be 100% sure that the 6 point komi is correct. When standard komi was first introduced, it was 1.5, then changed later to 2.5, 3.5, 4.5 until in the early 2000's it was changed from 5.5 to 6.5, because black was winning 55.6% (?) of the time, and that difference was deemed large enough to take action on the komi. There is practically nothing to go by except statistics. And if the stronger player happened yo have taken black 55.6% of the time, then the komi change would have been groundless. It could even have been the other way around, meaning they should have probably made the komi even bigger than 6.5. Ultimately, the only "proof" we have of whether komi is correct is whether it stands the test of time. Since we do not have enough years for the universe to live, we can never be sure. And this is were the half-point comes in.

"THE 0.5 IS IN GOD'S HANDS"

If in reality komi is too small, a draw is unfair to white. If komi is to large, a draw is unfair to black. The 6.5 komi does NOT say the komi is believed to be 6 points. It says, "We don't know whether it's 6 or 7, so we might as well make it 0.5 so that our tournament can run smoothly." Whether you agree with this or not is up to you, but the reasoning behind 0.5 is that we don't quite know true komi for sure anyway. By no means does every tournament have 6.5-- some have 6 or 7-- but it's rare in the pro world.
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