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 Post subject: Re: European Go Championship - Tournament Rules
Post #21 Posted: Thu Apr 29, 2010 1:47 am 
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kirkmc wrote:
Though Robert said, rather clearly, on RGG, that he doesn't like forums. I see that doesn't prevent him from posting in them.


I guess it gets lonely on RGG when everybody is here. If you can't beat them, join them.

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 Post subject: Re: European Go Championship - Tournament Rules
Post #22 Posted: Thu Apr 29, 2010 2:04 am 
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kirkmc, first let me clarify the context: In this context, "forum" means "topic section of a discussion medium", e.g., "Announcements" is the forum in which this thread is.

I have not said that I would not like forums. I have said that I dislike the (current) structure of forums on GD and the fact that it is a fixed rather than a dynamic structure.

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 Post subject: Re: European Go Championship - Tournament Rules
Post #23 Posted: Thu Apr 29, 2010 2:40 am 
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breakfast, thank you for pointing out the 1996 AGM's statement! This was a few months before I joined the Rules Commission. Of the 1996 AGM, I attended as a kibitz only for a couple of minutes because of playing in a tournament. At that time, AFAIK, AGM decisions were not published on the web yet. In the Rules Commission, none of the older members told me about that AGM decision. During tournament supervising, I think nobody recalled that decision. What we did recall was the EGF Fujitsu GP Guidelines / Regulations, which specified the supergroup and had pretty much the same contents, except that somehow the "up to" was lost over the years (or not in the Fujitsu rules; I would have to look up them to find out). Also nobody in the EGF Committee would notice the difference.

Now all that is history. Currently we have the ca. 32 and ca. 8 decision of the AGM 2008, which modifies the long-term practice of (usually) exactly 32 and up to ca. 8, provided a supergroup is formed at all.

So currently the Tournament Supervisors of an EGC have the power to interpret how far the "ca." can be applied. I guess that practice has been conservative (30 - 34) rather than liberal (say, 24 - 40). But in principle Tournament Supervisors might be somewhat liberal now, without needing a new AGM decision. "ca." would not mean "possibly 50% or less" though; there the rules would have to say "extremely roughly 32".

In practice, there would have to be reasons to depart from the standard. E.g., if we have a players field with 24 European or non-European players rated 2500+, then a gap and then lots of players with rating 2440-, I am pretty sure we would draw the line at the gap. However, in practice gaps near the bottom supergroup rating tend to be much smaller, maybe like 15 rating points.

If Matti and I are the Tournament Supervisors, we will probably usually be conservative about the "ca." interpretation. Maybe other Supervisors would be very liberal by default? The Rules Commission in the executive background would tolerate this, I think. We would not tolerate sudden extremes like 16 instead 32 though. This is not covered by "ca. 32" is I assume was also never intended by the 1996 text "up to 32".

Your suggestion 8 + 8 in the supergroup is bad, IMO. First of all, it is not guaranteed in every year to have 8 strong non-Europeans. Secondly, 8 Europeans is by far too small for a 10 rounds McMahon-with-supergroup. If you wanted to have such a tiny number, then you must ensure also a revision of the seeding criteria to have a much higher quality for them. If you suggest "Ca. 16 Europeans, up to ca. 8 non-Europeans, decided by AVERAGE rating during [some suitable period] and with a minimal number of X rated games during that period.", you increase chances that the AGM might consider a proposal of yours more seriously. Otherwise it might just be dismissed as "Alexander's election system":)

Even with such a system, you do not prevent place 1 - place 50 games. E.g., a strong player might have bad luck (very strong opponents) in the first two rounds and he would meet a weak opponent then.

What do you think about flexible number of rounds to determine the winner? Like 9 to 11 rounds, until exactly 1 player has the greatest McMahonScore? Then some top players' too weak opponents in a few rounds don't matter that much.

Something that has not been considered at all but maybe should: For the supergroup opponents, one might set a lower opponent rating bound, e.g., the rating of the (S*3)rd player in initial rating order, where S is the supergroup size. It would mean quite some manual tournament director interference though because I think pairing programs do not offer such a thing.

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 Post subject: Re: European Go Championship - Tournament Rules
Post #24 Posted: Thu Apr 29, 2010 4:38 am 
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Robert, if something works badly it's always possible to find people who is responsible and punish them.
For example, after Russian team got only few medals during the last Olympiad, lot of directors and presidents lost their places in Local Sport Federations.
How do you think, who is responsible for the lottery we have on EGC every year? If it's not you, please tell me his name.
I think it's good to prevent him from making any EGC-related decisions in future.

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 Post subject: Re: European Go Championship - Tournament Rules
Post #25 Posted: Thu Apr 29, 2010 6:00 am 
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The "lottery" aspect of the current EGC system is caused by several subaspects:

Relevant aspects:

A - Usage of final result tiebreakers that are only marginally better than lottery: SOS etc. (The various(!) side effects of opponent-dependent final result tiebreakers do not have to be considered in detail if only one does acknowlege their principle impact.)
B - Top Europeans can be paired against different numbers of top non-Europeans. Whether this is a lottery problem (preference whether top Europeans like or dislike many such games is an unrelated aspect) changes every year. In some years, top non-Europeans have very similar strengths to top Europeans and with a very similar distribution. In other years, top non-Europeans might be super-strong and then it really matters how many such opponents a European has to play against. Since the latter is possible at all, we need to consider this lottery aspect.
C - Some supposedly top non-Europeans do not have an EGF rating. This creates uncertainty whether a) they should be in the supergroup and b) how strong a European's opposition really will turn out to be.

Immaterial aspects:

- The seeding to the supergroup relies on weak data (any number of rated games suffices, only the moment just before the tournament is considered). Although this is relevant to some extent, if the supergroup is big enough, them we can as well assume that it is almost irrelevant for the stronger half of the supergroup members.
- Europeans having lived overseas might need to earn a new EGF rating. If they really are strong, then that should be easily possible for them.
- Some players cannot afford to travel to the tournament. This is a relevant issue but only marginally on the level of tournament system.
- The top players' field is a bit too thin or thick: All players are pretty equally affected by that.
- I think that the varying strength of the players' opposition can be neglected because the typically used pairing programs try to make SOS values of players similar. To really see clear causes of still remaining differences requires lots of research, which has not been done yet. So we may as well simplify here and ignore this lottery aspect. (In tournaments with only a few rounds, matters are very different though. An EGC with a too big number of top non-Europeans would also still create problems, but this is a special case.)
- A player is paired against his angst opponent. This is the player's psychological responsibility rather than a fault of the tournament system.
- A player gets the "wrong" color against a specific opponent. It is the player's responsibility to play well with both colors.
- A player prefers a different komi, scoring, thinking time, starting time of a round etc. Maybe relevant for the individual but we cannot do much by trying to replace the tournament system.

Responsibility for the relevant aspects:

It is rather nebulous who might be responsible for maintenance of aspects B and C. Besides these aspects are not as relevant as A. So the major aspect for which responsibility should be studied is A. Responsible are all those delegates and their direct or indirect supporters that have rejected, have delayed or reject tournament systems for that A plays a role at all. IMO, this lets most delegates and the EGF Committee be responsible. Also many supporters of maintaining SOS as the first tiebreaker.

It is easier to say who is not responsible: Those having made system change proposals so that opponent-dependent final result (or relevant seeding to a next tournament stage) tiebreakers are not needed.

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 Post subject: Re: European Go Championship - Tournament Rules
Post #26 Posted: Fri Apr 30, 2010 2:46 am 
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For those of us who are not TD's...

SOS, SOS-1, SOS-2, can I get a link to the different kind of tiebreakers these are?

is SOS-2 SODOS?


Breakfast: I dunno, you've been in more situations where tiebreakers count, which method of tie-breaking do you prefer?

(P.S. I love the quote...)

I only ask because, my impression is, as a player who's been on the low end of American supergroups. It's hard to reduce the supergroup without also reducing excitement about the tournament. People like having a hometown hero in the mix, even if they know they're going to get smashed.

I feel like a good implementation of SOS would be less damaging to the format than cutting players out of the running...

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 Post subject: Re: European Go Championship - Tournament Rules
Post #27 Posted: Fri Apr 30, 2010 3:36 am 
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From what I understand, SOS-1 is SOS with an opponents score removed. I don't know if it's the worst, but I assume so.

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 Post subject: Re: European Go Championship - Tournament Rules
Post #28 Posted: Fri Apr 30, 2010 4:38 am 
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For those not knowing the tiebreaker yet, it is defined in the rules themselves:

http://home.snafu.de/jasiek/EuropeanCha ... Rules.html

"SOS-x ignores the lowest McMahonScores of a player's opponents in exactly x rounds."

The EGF Tournament System Rules

http://home.snafu.de/jasiek/egftsr.html

define at least the first two:

# SOS-1 = SOS, where 1 round with the smallest value is ignored.
# SOS-2 = SOS, where 2 rounds with the smallest values are ignored.

***

"a good implementation of SOS" is: Do not use it for the final results ordering. A player should always be responsible for his final placement, which contradicts that he cannot influence his SOS value well.

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 Post subject: Re: European Go Championship - Tournament Rules
Post #29 Posted: Fri Apr 30, 2010 5:22 am 
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huh, that seems odd to me,

I could understand taking out earlier rounds, but taking out the lowest round feels weird.

Suppose you had a very long (but not round robin) tournament, with a large number of players, each player would converge to their appropriate placing pretty quickly no? even with incomplete information. But suppose you stop it before it's "done", and then weight the earlier round information the same as the later round information, then you're overcompensating for earlier rounds.

Why? By virtue of the fact that the existing information that can be gleaned about each player's performance is already, in a sense, locked up in who they're playing in later rounds.

for example, suppose we have the following performance:

(1's are wins, 0's are losses. Number below is current rank of opponent)

1 1 0 1 1
10 8 4 6 3

Now, I've heard of people subtracting the first round, but it seems to me that if we know that this player is playing against player number 4 in the third round, then that already tells us a lot of information about the player, the result of this game is more significant than the game preceeding it.

So why not establish a statistic which starts with:

Tiebreak one: Sum of scores (weighted by significance)
Tiebreak two: Sum of opponent's weighted scores
etc...

... Or has this already been done?

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 Post subject: Re: European Go Championship - Tournament Rules
Post #30 Posted: Fri Apr 30, 2010 8:03 am 
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Look at some earlier EGC final result tables for top players! You will notice that low SOS values of weakly performing opponents occur in up to ca. 2 rounds and do NOT always occur for the first two rounds (for some players, their lowest SOS contribution is in some seemingly unpredictable rounds). Therefore SOS-2 is the opponent-score dependent tiebreaker with the greatest meaning. SOS-1, SOS-3, SOS-R1, SOS-R2, SOS-R3 (Rx meaning: drop first x rounds), SOS each has less meaning.

What do you mean with "weighted by significance"? Which significance?

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 Post subject: Re: European Go Championship - Tournament Rules
Post #31 Posted: Fri Apr 30, 2010 8:32 am 
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RobertJasiek wrote:
What do you mean with "weighted by significance"? Which significance?


later rounds have higher significance than earlier rounds?

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 Post subject: Re: European Go Championship - Tournament Rules
Post #32 Posted: Fri Apr 30, 2010 9:22 am 
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What I mean is,

if we take a game to be a test, each test gives us some information about the player, there is a pairing based on that information, which leads us to the second test. That test now contains some of the information of the previous round of both players (limited by the pairing algorithm).

As you continue, later rounds contain more and more information. Hence, you should be able to develop a value for the significance of each round. In my previous example, the player's score at the end of the 5 rounds is 4-1.

now suppose he's tied with another 4-1. A very simple weighting algorithm (and probably wrong, since the significance of certain bouts may be reduced by other factors) would be the following:

0.5 0.6 0.7 0.8 0.9

which by a weighted average would give the player a tiebreaker score of 0.8
in the unlikely circumstance that two players share the same weighted score, you then do the sum of opponents scores, weighted by the same values that the wins were.

A more likely outcome would use the shannon information, you ask, based on the comparative ratings (your previous knowledge of both players), how much can this pairing actually tell us?

Then one wins and now you compute new performance ratings. You then attempt to maximize the information gleaned out of the next round, by judicious pairing.

so for this particular player, based on the field, suppose the information gained in each round looked something like this:
(remember, this player went 1,1,0,1,1)

0.4 bits | 0.8 bits | 0.5 bits | 0.9 bits | 1 bit

so in the first round he faced someone he overmatched, so we get very little information out of it, in the second the pairing was close, in the third there was a gap in player strength, he rose "too high" as it were. In the fourth he had a very well placed match, and in the 5th he had a perfect match.

so the cumulative information would be:

0.4 | 1.2 | 1.7 | 2.6 | 3.6

and his weighted average would be 0.62


A tournament is a test, the goal is to structure the test to get the most information out of it, as well as to interpret results based on how much information we gleaned from them.

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 Post subject: Re: European Go Championship - Tournament Rules
Post #33 Posted: Fri Apr 30, 2010 4:07 pm 
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breakfast wrote:
I am sure, that making supergroup smaller solves all our problems with SOS/SODOS champions.
I will vote against any new systems (cannot vote, actually, but I prepared a tesuji). I will be Belorussian representative this time :)
Someone has to defend the interests of top Europeans. I will be the first one!


Well, I don't support a reduction in supergroup size.

Reducing the supergroup size may be in the interests of the top (known) European players - but it would reduce the chance of an outsider becoming champion I believe.

For me, as a participant and spectator and with the interests of as successful an EGC as possible, I would like the restrictions on Asian players in the supergroup to be relaxed.

I feel that somehow we should also reward top players who attend a lot of European events.

I also liked the suggestion that lightning matches be used to resolve drawn places.

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 Post subject: Re: European Go Championship - Tournament Rules
Post #34 Posted: Sat May 01, 2010 1:45 am 
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shapenaji, the simplest tiebreaker according to your idea that later rounds have monotonously increasing significance is IROS: r points in round r. However, it is wrong to assume such. E.g., a player having already beaten all the top competitors then necessarily is paired against weaker players again.

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 Post subject: Re: European Go Championship - Tournament Rules
Post #35 Posted: Tue May 04, 2010 1:50 pm 
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RobertJasiek wrote:

Currently the EGF Rules Commission consists of Matti Siivola (chairman, FI) and me.


That is not very much, that is not even one representative per member organisation.


RobertJasiek wrote:

If you want to suggest that there is a conflict of interests between the strong players among the Tournament Supervisors and objective supergroup forming: Yes, there is. We have been aware of it and usually have let third persons double check when some of us supervisors was at the lower boundary of a supergoup. If you consider that insufficient, then please propose capable and rules-firm weak players who want to do the job of the Tournament Supervisors! It would save me of 8 - 20 hours of work every year.



I did some thinking and allready alone in the UK I can find 6 candidates (not counting myself) who are capable for different parts of a tournament supervisor job.
(but for some problems might need a strong player)

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 Post subject: Re: European Go Championship - Tournament Rules
Post #36 Posted: Tue May 04, 2010 2:10 pm 
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I strongly suspect that the only reason that that commission is so small is that no one else wants to do that job.

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 Post subject: Re: European Go Championship - Tournament Rules
Post #37 Posted: Tue Jun 22, 2010 9:05 am 
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RobertJasiek wrote:
shapenaji, the simplest tiebreaker according to your idea that later rounds have monotonously increasing significance is IROS: r points in round r. However, it is wrong to assume such. E.g., a player having already beaten all the top competitors then necessarily is paired against weaker players again.


Sorry Robert, I know it's been a while, but I was thinking about this.

If we define a concept the "information gained from a match", (For which we use the Shannon's information based on the probability of winning given the current tournament ratings in that round), to weight the monotonically increasing values, then if a player runs out of players his own strength and has to start playing weaker players, the weighting would be dropped by using the corresponding drop in the information gained from the match.

Of course this would mean that in order for players to have an opportunity to get the best tiebreaking scores they can, the pairing software should act in such a way as to maximize the Shannon information gained from each round.

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