From: Pieter Stouten shogi net> Date: 21 sep 2004 Subject: Re: SOS-based pairing at the ESC/WOSC Your free subscription is supported by today's sponsor: ------------------------------------------------------------------- Is America Safe? Give your opinion on Homeland Security and enter=20 to win! http://click.topica.com/= caacERTa2i6YsbnuqMaa/PermissionData ------------------------------------------------------------------- Hello Shogi fans, I think between them Jochen and Eric have identified many if not all pros and cons of the SOS-based pairing system, and this will help FESA a lot. One word I don't think belongs in the discussion is that of "punishment". I know it was put between quotes to soften it up, but I would argue that the Elo-based system allows for unfair advantages and disadvantages, while the SOS-based system actually compensates for them. Below the exchange between Eric and Jochen, I'll show you why. Jochen wrote: >>>2. The global number of players paired up or down has to be >>>minimized. Eric wrote: >>Nothing about a rule preventing a player from being "punished" >>several times in the tournament as in the swiss system. Jochen wrote: >If you mean as a result of unavoidable disatvantageous pairings, >you are right that the rules do not mention that directely. >However, the rules are more like axioms that have to be followed >by the pairing methode. The pairing method itself guarantees that >no player is treated worse than any other player. Eric argued that it is unfair if a player "X" is paired "down" more than once in a tournament. Let's make it even worse and assume that that same player X was never paired "up" in that tournament at all. But wait a minute: how then is it possible that X got such a high SOS that he got paired "down" twice? The reason is that one or more of X's opponents, who were in his point group when he was paired against them went on and scored many points. So, in retrospect, X was paired "up" (as evidenced by his high SOS), although when the pairing took place (e.g., fairly early in the tournament) this was not evident. The advantage of the SOS-based pairing is precisely that it continuously (after each round) re-assesses how many times each player was in actuality paired "up" and "down" based on all results up to that time, and on the basis of that evaluation decides which players to pair "up" and "down." I personally cannot imagine anything that is fairer than that. Ciao, Pieter Your free subscription is supported by today's sponsor: ------------------------------------------------------------------- Race to Claim your FREE Stock Car Racing Gift! http://click.topica.com/= caacERRa2i6YsbnuqMaf/PermissionData ------------------------------------------------------------------- --^---------------------------------------------------------------- This email was sent to: = shogi-l shogi net EASY UNSUBSCRIBE click here: http://topica.com/u/?a2i6Ys.= bnuqMa.= c2hvZ2kt Or send an email to: shogi-unsubscribe topica com For Topica's complete suite of email marketing solutions visit: http://www.topica.com/?p=3DTEXFOOTER --^----------------------------------------------------------------