Tie Breaker/ Discussion

IanDavis: With regard to Tiebreakers, this page claims that SOS/SODOS is the most widely used. The page on SODOS claims it is flawed because it is not invariant when you switch between the Euro-UK/UK systems. I haven't seen anyone dispute this flaw. Does this means that SOS/SODOS suffers from the same problem?

Also how does this sound as a tiebreaker method SOP - sum of places - lower SOP being better. Before tiebreakers are applied everoyne sits on a position determined by MMS or raw points. eg: 1st ; 4th ; 5-9 (we cal this 7) . So to find somebodies SOP add together the finishing positions. Is this equivalent to SOS?

Tapir: It is a wiki! Please change on the main page if you think anything is inappropriate.

Anonymous: Speaking of tiebreakers, isn't it incorrect to take the arithmetic mean of schedule strength? Shouldn't it be the geometric mean? You should calculate the estimated probability of losing each game, and multiply them together. For example, two players play the exact same opponents, except the second plays an extra game against a weak player (with the other getting a bye). The opponent strength should be equal, but average strength favors the player with one fewer game. Or consider each player plays two games, where one player plays a top pro and a beginner; the other plays two intermediate players. Who had the tougher opponents? This problem is particularly notable in college football, where teams play a different number of games and different opponents.

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PAG?: If the reward is to be given to the "strongest player", why not sticking to the swiss system for qualifications only (4 to 8 groups), then Quarter finals, Semi finals and final. Wouldn't it make sense to have a stronger player winning rather than a 25kyu actually playing as a 15 kyu, winning all his/her games and being lucky enough to get a good SOS? That of course implies that the Tournament's Board wants to reward the strongest players. "Best performers compared to current rank" could then be evaluated separately. That would restrict the use of tie breakers, and would increase the need for separate Kyu tournaments of course. Am I missing something? Go is intellectually satisfying, because luck has little say in the game. Why not keep it to the minimum, at least for the few last games (more important because of Price for winners)

Dieter: The 15 kyu will not win if the tournament is organized with the McMahon method, which in some other cases also leads to unfair results.

RobertJasiek, 2010-01-22: Can't we just have pages that are nothing but reasonable? The current version of the page Tiebreaker is not: There is an arbitrary classification between List of Used Tie Breakers and Theoretical and Didactical Tie Breakers. Some tiebreakers have nothing but a shortest definition (like "SOR: sum of ranks") while other tiebreakers have lots of details and even opinion (like "ROS: [...] Designed for the didactical purpose to expose CUSS and SOS-type tie breakers."). Some tiebreakers are listed where they belong (like SOSOS to SOS) while others are not where they belong (like ROS). Where is the evidence for Common combinations of tie breakers? - A reasonable page should state facts only and treat all tiebreakers equally! We have the more specific pages to explain each tiebreaker in detail anyway.

tapir: Actually I prefer to make a tie breaker path where all tie breakers were listed (and sorted according to family ties, CUSS and ROS together that is) and remove the theoretical ones here altogether. No representation without application! You added the details at ROS, reg. my remark - well my intention for "SOL" was didactical, I thought yours was the same. The combinations well change it as it suits you, you can even remove the combination part completely.

isd: There is a problem that a lot of what is written about many tiebreakers is simply false. Therefore arguing that some tiebreakers should be treated more seriously than others because they have been documented is highly suspect. I see nothing wrong with the current set up on the page, list tiebreakers that are used, list some others you might choose.

RobertJasiek: What about keeping the page Tiebreaker general without listing any specific tiebreaker and creating a new page Tiebreaker List, which would then simply list all?

isd: Seems an entirely pointless suggestion? The page is a well laid out source of information for tiebreakers as it is.

RobertJasiek: It is inconsistent and biased, see above.

isd: It looks informative to me.

RobertJasiek: It is, as you say, a) informative and b) what is written about many tiebreakers is simply false. I think we will only ever come to an agreement if we keep the central pages as simple as possible. Then they state universally accepted truths only and we can concentrate on discussing the things of differing opinions.

isd: I was refering mostly to what was written on the discussion pages, the linked external pages and on some individual tiebreaker pages, not the tiebreaker homepage itself. That page is quite informative.