Page 1 of 2 12 LastLast
Results 1 to 15 of 30
  1. #1
    CC Grandmaster Desmond's Avatar
    Join Date
    Apr 2006
    Location
    The island
    Posts
    14,205

    Absences skew the draw

    http://www.crcchess.com/Results/index.html

    In rd 6 (penultimate round) we had a bit of an unusual pairing due to absences in the field. Basically, I just wanted to know if there can be no valid draw made because too many players have met before, what is the procedure? Do players get paired against someone they have played already? Do players who cannot be paired receive a full-point bye (even if this is more than 1 player)? Or some other option?
    So what's your excuse? To run like the devil's chasing you.

    See you in another life, brotha.

  2. #2
    CC Grandmaster Basil's Avatar
    Join Date
    Mar 2006
    Location
    Subtropical Brisbane, Australia
    Posts
    11,245
    Nice question!
    There is no cure for leftism. Its infestation of the host mostly diminishes with age except in the most rabid of specimens.

  3. #3
    CC Grandmaster Garvinator's Avatar
    Join Date
    Jan 2004
    Location
    Brisbane
    Posts
    13,310
    Hello Brian,

    Before I answer, was this a pairing done manually or by computer? If computer, what pairing program was used. This is so I know roughly what pairing laws were used.

  4. #4
    CC Grandmaster Desmond's Avatar
    Join Date
    Apr 2006
    Location
    The island
    Posts
    14,205
    Quote Originally Posted by ggrayggray
    Hello Brian,

    Before I answer, was this a pairing done manually or by computer? If computer, what pairing program was used. This is so I know roughly what pairing laws were used.
    I'm afraid I don't know the answer for sure, but I would assume Swiss Sys was used. No manual adjustments afaik.
    So what's your excuse? To run like the devil's chasing you.

    See you in another life, brotha.

  5. #5
    CC Grandmaster Basil's Avatar
    Join Date
    Mar 2006
    Location
    Subtropical Brisbane, Australia
    Posts
    11,245
    I'd like to see your answer of what you believe is correct before he answers that!
    There is no cure for leftism. Its infestation of the host mostly diminishes with age except in the most rabid of specimens.

  6. #6
    CC Grandmaster Garvinator's Avatar
    Join Date
    Jan 2004
    Location
    Brisbane
    Posts
    13,310
    Ok, looking at the pairings and before Bill answers

    I think the pairings should have been:

    Cashman/Hunter
    Thomas/Bargo
    McClymont/Truscott
    Weller/Stokes.

    These were worked out quickly, trying to pair just like in a tournament, so I might have missed something, but they seem more sensible than what was paired.
    Last edited by Garvinator; 10-11-2007 at 02:15 AM.

  7. #7
    CC Grandmaster Desmond's Avatar
    Join Date
    Apr 2006
    Location
    The island
    Posts
    14,205
    Thanks for that Garvin, but what about my original questions?
    So what's your excuse? To run like the devil's chasing you.

    See you in another life, brotha.

  8. #8
    CC Grandmaster Garvinator's Avatar
    Join Date
    Jan 2004
    Location
    Brisbane
    Posts
    13,310
    Quote Originally Posted by Boris
    Thanks for that Garvin, but what about my original questions?
    What about your original questions

    In rd 6 (penultimate round)
    Looks like final round to me.

    Basically, I just wanted to know if there can be no valid draw made because too many players have met before, what is the procedure? Do players get paired against someone they have played already? Do players who cannot be paired receive a full-point bye (even if this is more than 1 player)? Or some other option?
    I don't believe there is a strict procedure in this case and so it would be a matter of making new pairings that affect the tournament the least.

    So if there were no legal pairings in the linked round, I would have paired the two lowest scoring players together.

  9. #9
    Monster of the deep Kevin Bonham's Avatar
    Join Date
    Jan 2004
    Posts
    40,358
    Quote Originally Posted by Boris
    Basically, I just wanted to know if there can be no valid draw made because too many players have met before, what is the procedure? Do players get paired against someone they have played already? Do players who cannot be paired receive a full-point bye (even if this is more than 1 player)? Or some other option?
    There actually is no specified procedure in the pairing rules because it is assumed the tournament will be designed such that this will never happen.

    B1(a) Two players shall not meet more than once.

    and

    B1(b) A player who has received a point without playing, either through a bye or due to an opponent not appearing in time, shall not receive a bye.

    have no specified override, so it is up to the arbiter's discretion.

    Garvin's suggestion of shuffling the damage to the lowest possible board is a good one and is consistent with the principles of the system.

    I had a rapid junior muckaround tournament with about ten players once where some had entered late and some had to leave early, and SP told me that it could not pair round five. I suspected that there was a valid legal pairing but I did not have time to look for it so I simply declared the tournament finished as of round four and suggested everyone have a practice game instead of the final round.

    I have just noticed something interesting regarding SP and player absences. Not sure how other programs deal with this. If a player is known to be absent in advance for a round and given zero, there is nothing in the rules I can see that prevents this player subsequently being given a bye. But SP can only code an absence as a bye (whatever its value) and therefore will not permit that player to receive any further byes.

    Example - it is known that player Z will miss round one and player Z is therefore not paired for that round and scores zero. Every other game is drawn. In round 2, player Z should now receive the bye, but SP won't allow it. Indeed I have just tested this and found that SP will never give Z the bye, not even eight rounds later.

    A hack around this is to not include Z in the list of players until round 2 starts, but in the case of an absence after round 1 this is not possible. An alternative would be to enter a fictional opponent for Z for that round only.

  10. #10
    CC Grandmaster Denis_Jessop's Avatar
    Join Date
    Jan 2004
    Location
    Canberra
    Posts
    3,333
    Quote Originally Posted by Kevin Bonham
    I have just noticed something interesting regarding SP and player absences. Not sure how other programs deal with this. If a player is known to be absent in advance for a round and given zero, there is nothing in the rules I can see that prevents this player subsequently being given a bye. But SP can only code an absence as a bye (whatever its value) and therefore will not permit that player to receive any further byes.
    We had quite a debate about this kind of situation on the Canberra Chess e-mail list a few years ago when the argument was about whether a half-point bye prevented a player from later getting a full-point bye. It's common practice in Canberra (and, I think elsewhere,) to allow a player a "half-point bye" upon prior notice in which case the player is given half a point and left out of the draw. This debate happened before Swiss Perfect was being used and I argued that such a person could later be allowed a bye as the half-point bye was not really a bye. Nobody else agreed and, when I later began to use SP, I noticed, as you have, that it treats such a case as a bye and won't allow the player to have another. I didn't bother about it any more as the majority of local players who has expressed a view took that one anyway.

    Neither the case of a 0-point nor half-point bye (of the kind we are talking about) seems to be taken into account in the Swiss Rules, perhaps because A5 assumes that a player will receive a full point for a bye and B1(b) is addressing that situation when referring to a bye.

    It seems fair enough that a player should not receive two free points in a tournament as provided in the Swiss Rules but if a player is left out of the draw and not given a point, there doesn't seem any reason for that player not receiving a bye later, that is, a bye under the pairing principles. I had argued that if a player is left out of the draw and given a half-point bye, that is not a "bye" as referred to in the Swiss Rules and the same argument would apply to a 0-point bye only more so. Curiously, if B1(b) is applied literally to half-point byes, it could allow a player who has had one, but not more, to have a bye later. In fact, in my view, the situation is just not addressed by the Swiss Rules and SP is avoiding the issue by not allowing at least a 0-point "bye" player to be later given a bye.

    DJ
    Last edited by Denis_Jessop; 10-11-2007 at 02:39 PM.
    ...I don't want to go among mad people Alice remarked, "Oh, you can't help that," said the Cat: we're all mad here. I am mad. You're mad." "How do you know I'm mad?" said Alice. "You must be," said the Cat ,"or you wouldn't have come here."

  11. #11
    Monster of the deep Kevin Bonham's Avatar
    Join Date
    Jan 2004
    Posts
    40,358
    The rules don't allow for a player who has had a half-point bye to later get a full-point bye for a simple reason: the rules don't include the concept of a half-point bye in the first place. A player is either known "in advance not to play in a particular round" hence scoring zero (F5) or else receiving a full point bye (A5). Therefore the situation isn't envisaged and is up to the arbiters' discretion.

    I'm assuming that those drafting the rules would have envisaged the situation of a player having one or more zero-point absences and then later getting a full-point bye, and would have put something in to stop that situation if bothered by it. (Admittedly this is a risky assumption given how shockingly drafted the rules are generally). On that basis I see no reason why a player who has had a zero-point absence cannot get a full-point bye, although there are many reasons an arbiter might exercise discretion to avoid it.

  12. #12
    CC Grandmaster Denis_Jessop's Avatar
    Join Date
    Jan 2004
    Location
    Canberra
    Posts
    3,333
    Quote Originally Posted by Kevin Bonham
    The rules don't allow for a player who has had a half-point bye to later get a full-point bye for a simple reason: the rules don't include the concept of a half-point bye in the first place. A player is either known "in advance not to play in a particular round" hence scoring zero (F5) or else receiving a full point bye (A5). Therefore the situation isn't envisaged and is up to the arbiters' discretion.

    I'm assuming that those drafting the rules would have envisaged the situation of a player having one or more zero-point absences and then later getting a full-point bye, and would have put something in to stop that situation if bothered by it. (Admittedly this is a risky assumption given how shockingly drafted the rules are generally). On that basis I see no reason why a player who has had a zero-point absence cannot get a full-point bye, although there are many reasons an arbiter might exercise discretion to avoid it.
    Kevin

    I'm not sure that I fully agree because half-point byes are not unknown elsewhere. Moroever, I note that F5 says "They score 0 unless the controller agrees otherwise" and so the drafters of B1(b) should have foreseen the case of an F5 player being awarded something other than 0, for example half a point. See also Art. 11.1 of the Laws that allows for the possibility of a winner on forfeit receiving a score other than 1.

    I note also that the rules allowing awards of scores other than 1 or 0 were introduced after B1(b). Both F5 and Art.11.1 were changed between 1997 and 2001 while B1(b) was in its present from in 1997, in the case of F5, the words in italics if F5 quoted above were added.

    Thus we have a case of the drafters in 2001 (or thereabouts) not having followed up all the consequentials when they amended the rules - an elementary drafter's error.

    Incidentally, I see that Stewart Reuben, in discussing Swiss Pairing Systems, refers to the practice of giving half-point byes in the first and second editions of his "Chess Organiser's Handbook" (at pp48 and 37 respectively) but I cannot find the equivalent passage in the third edition. Nor does Stewart tie his comments in with the operation of the Dutch System Swiss pairing rules.

    DJ
    Last edited by Denis_Jessop; 10-11-2007 at 08:25 PM. Reason: Substantiallyrevised opinion
    ...I don't want to go among mad people Alice remarked, "Oh, you can't help that," said the Cat: we're all mad here. I am mad. You're mad." "How do you know I'm mad?" said Alice. "You must be," said the Cat ,"or you wouldn't have come here."

  13. #13
    Monster of the deep Kevin Bonham's Avatar
    Join Date
    Jan 2004
    Posts
    40,358
    Quote Originally Posted by Denis_Jessop
    Kevin

    I agree absolutely - even to the expected foresight of the drafters. But I also believe that half-point byes are not unknown elsewhere and I note that F5 says "They score 0 unless the controller agrees otherwise"
    In what version (or source) of the rules does that wording of F5 appear? I haven't seen that wording before and the current wording on the FIDE website under FIDE Swiss Rules is:

    Players who withdraw from the tournament will no longer be paired. Players known in advance not to play in a particular round are not paired in that round and score 0.

  14. #14
    Illuminati Bill Gletsos's Avatar
    Join Date
    Jan 2004
    Location
    Sydney
    Posts
    17,058
    The wording that Denis quoted is from the 2nd edition of Reuban's Chess Organisers Handbook.

    The wording of F5 in the First edition and the Third edition are the same as what is currently on the FIDE website.
    The Force can have a strong influence on the weak-minded.
    Mos Eisley spaceport The toolbox. You will never find a more wretched hive of scum and villainy.

  15. #15
    CC Grandmaster Denis_Jessop's Avatar
    Join Date
    Jan 2004
    Location
    Canberra
    Posts
    3,333
    Quote Originally Posted by Kevin Bonham
    In what version (or source) of the rules does that wording of F5 appear? I haven't seen that wording before and the current wording on the FIDE website under FIDE Swiss Rules is:
    Sorry Kevin, I have just done a major redraft of my views that now explains things more clearly, I hope. Meanwhile, I missed your response to my earlier version and Bill's post as well

    DJ
    ...I don't want to go among mad people Alice remarked, "Oh, you can't help that," said the Cat: we're all mad here. I am mad. You're mad." "How do you know I'm mad?" said Alice. "You must be," said the Cat ,"or you wouldn't have come here."

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Draw by Repition in blitz
    By arosar in forum Arbiters' Corner
    Replies: 12
    Last Post: 06-07-2010, 08:51 PM
  2. Sydney grade matches joke
    By Javier Gil in forum Completed Tournaments
    Replies: 250
    Last Post: 11-12-2005, 09:33 PM
  3. Draw in ten moves or less ...
    By Kevin Bonham in forum Chess Training
    Replies: 4
    Last Post: 21-09-2005, 09:50 PM
  4. When is a draw O.K?
    By Mischa in forum General Chess Chat
    Replies: 35
    Last Post: 20-05-2005, 06:59 PM
  5. predictions for each game in the championship section
    By Garvinator in forum Completed Tournaments
    Replies: 172
    Last Post: 24-01-2004, 06:11 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •