Answers.Body: <p>The current algorithms are deterministic. I have no idea why you would want a <em>non</em>-deterministic algorithm. The advantage of the deterministic ones we currently use is that they can be easily done by hand (and were done by hand until quite recently), so if a TD changes them manually that can be detected.</p>
  
  <p>Gender of the players is not an input to the algorithm at all. It does not play a role whatsoever.</p>
  
  <p>Hou Yifan had a very unusual draw in this year's Gibraltar and the first four rounds of Isle of Man; but that's just a coincidence. Something like that has never been noticed with any other women or other tournaments or other years.</p>
  
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Answers.Text: That's a tautology... what's the advantage?
Answers.UserDisplayName: RemcoGerlich
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Answers.Text: Yes, I know what the word means. A deterministic system always has one clear next step and will always lead to the same output given the same input, a nondeterministic system doesn't. Hou Yifan didn't ask for a non-deterministic one, and so far it's always been seen as an essential feature that the algorithms used must be deterministic, so it can be easily checked that the pairings haven't been tampered with. Hou Yifan suspected tampering, so she would be very much in favour of that. You are the first one I ever hear who wants a nondeterministic algorithm, and I'm asking for a reason _why_.
Answers.UserDisplayName: RemcoGerlich
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Answers.Text: Tampering is a big problem because organisers try to give their local boy who is trying for a GM norm easier pairings, or just their friends. If the algorithm were non-deterministic, they could always claim it was just randomness. Deterministic is fairer, the same rules for everyone, all the time.
Answers.UserDisplayName: RemcoGerlich
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Answers.UserDisplayName: RemcoGerlich
Answers.Body: <blockquote>
    <p>Surely we can create opt out for gender pairings which occur
    consecutively?</p>
  </blockquote>
  
  <p>Yes, we could.  We can make whatever rules we like, after all.  But I don't think we should.</p>
  
  <p>Such a rule would have to come at the expense of some other pairing rule.  We currently have rules that players cannot play each other twice, that players with equal scores should play each other, that colors should be equalized, etc.  Which of the existing rules are less important than equalizing which gender a player will play?</p>
  
  <p>Such a rule would also imply that playing females is somehow undesirable, or gives an inherent advantage or disadvantage compared to playing males with the same rating.  I don't think these are views FIDE wants to encourage.</p>
  
  <p>And any rule that makes things "non-deterministic" makes it harder for FIDE to verify that the pairings were not manipulated.  (If we did have such a rule, why would it not be deterministic?)</p>
  
  <blockquote>
    <p>It is clear that rules make it more likely for Hou Yifan to be paired with women as there is an elo gap in mean the population of male elite GMs and female elite GMs and the lowest elo on the highest score and highest elo on lowest score pairing pattern used increases the likelihood of these gender-specific pairings.</p>
  </blockquote>
  
  <p>First of all, people with "highest" and "lowest" scores are very unlikely to play each other.  Perhaps you meant "higher" and "lower".</p>
  
  <p>Second, there are pairing rules about minimizing the number of people who get the same upfloat/downfloat as the previous round, or two rounds ago, so while this may be a factor for some players, it won't happen every round, or even every other round.</p>
  
  <p>Third, in both Gibraltar and Isle of Man, she did not float (in either direction) in any of the rounds, so this was pretty much irrelevant.  It was sheer luck that she was paired with women.</p>
  
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Answers.CreationDate: 2017-10-02T13:58:17.853Z
Answers.Text: The opt outs for people in the same team, federation and family. An opt out for players of the same gender is not as silly as it sounds since most women play in a gender specific tournaments and have not got the same or similar population spread as the open tournaments. That is the reason for this opt out. Think approximation to the normal distribution of two populations with different means.
Answers.UserDisplayName: Michael Chukwuma Mkpadi
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Answers.CreationDate: 2017-10-02T15:43:56.653Z
Answers.Text: Did those two tournaments accept opt outs for people in the same team/federation/family?  I'm guessing not, as that would have affected things in the report on Gibraltar pairings that TMM referenced in his comment.
Answers.UserDisplayName: D M
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Answers.CreationDate: 2017-09-28T23:22:01.770Z
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Answers.UserDisplayName: D M
Answers.Body: <blockquote>
    <p>The question is can we not design a simple non-deterministic swiss
    pairing system that does not penalise the "outliers" of the female
    population of players?</p>
  </blockquote>
  
  <p>What you are saying is sexist and very offensive. You are saying that when Hou Yifan is paired against other female players she is "penalised".</p>
  
  <p>It is correct and fair that the pairing systems are required to be gender neutral.</p>
  
  <p>Your suggestion that -</p>
  
  <blockquote>
    <p>Surely we can create opt out for gender pairings which occur
    consecutively?</p>
  </blockquote>
  
  <p>offends against one of the basic principles laid down in the  <a href="https://www.fide.com/fide/handbook.html?id=84&amp;view=article" rel="nofollow noreferrer">General handling rules for Swiss Tournaments</a> in the FIDE Handbook - </p>
  
  <blockquote>
    <p>A. Pairing Systems</p>
    
    <p>...</p>
    
    <p>5 It is not allowed to alter the correct pairings in favour of any
    player.</p>
  </blockquote>
  
Answers.ContentLicense: CC BY-SA 3.0
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Answers.Text: I would be grateful if you did not resort to personal comments here. I am free to ask a question here without being accused of being sexist and being offensive. The question is about gender. If Hou Yifan didn't have a problem with her pairings I would not have posted this question. Is Hou Yifan sexist for wondering if her pairings of 4 consecutive females in two consecutive opens is truly objectively by non-gender biased rules or subjective or manipulated in some way. Is she sexist? I think not so please do not accuse me of being sexist.If questions about gender offend you then don't read them
Answers.UserDisplayName: Michael Chukwuma Mkpadi
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Answers.Text: "Is Hou Yifan sexist for wondering if her pairings of 4 consecutive females in two consecutive opens is truly objectively by non-gender biased rules or subjective or manipulated in some way." - It was perfectly reasonable for her to wonder, as such pairings are unlikely.  But resigning in protest when things were *verifiably* not manipulated was not reasonable.
Answers.UserDisplayName: D M
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Answers.Text: Totally agree @DM. I wonder why a lot of people think my question implies the FIDE laws are at fault or the organisers or software are to blame. FIDE Laws work and the organisers and pairing software are blameless. Hou Yifan is to blame for assuming a non-bias statistical trial like a swiss tournament pairing system is biased. I am asking intellectually what can be done to take it beyond all doubt. It is a question and I'm only asking it. I have a right to ask any question, right?
Answers.UserDisplayName: Michael Chukwuma Mkpadi
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Answers.Text: @Michael FWIW my comment was aimed at Brian Towers. (My previous comment saying this answer is offensive was removed, presumably because Brian thought my comment hurt his feelings. Apparently Brian is the only one allowed to offend others here.)
Answers.UserDisplayName: TMM
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Answers.Text: @DM You are assuming Hou Yifan also knew this. At the time she likely did not know these pairings are verifiable, and that verifying this would show the pairings were not manipulated. (If she did, I am sure she would not have made a big deal out of it.)
Answers.UserDisplayName: TMM
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Answers.Text: @TMM Obviously she didn't know, but someone of her standing should have done some research before throwing accusations around.  Pairing rules are easily available online.
Answers.UserDisplayName: D M
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Answers.CreationDate: 2017-09-28T09:57:21.667Z
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Answers.UserDisplayName: Brian Towers
Body: <p>I have been following the controversy surrounding the pairings of Hou Yifan at the IOM chess tournament 2017. She was paired with 4 consecutive female players, this is following her last open swiss tournament outing in Gibraltar where she was paired with 7 female players from 10 pairings, including round 1 - 4 consecutive female-female pairing as in IOM 2017. </p>
  
  <p>The question is can we not design a simple non-deterministic swiss pairing system that does not penalise the "outliers" of the female population of players? It is clear that rules make it more likely for Hou Yifan to be paired with women as there is an elo gap in mean the population of male elite GMs and female elite GMs and the lowest elo on the highest score and highest elo on lowest score pairing pattern used increases the likelihood of these gender-specific pairings. Any ideas?</p>
  
  <p>Surely we can create opt out for gender pairings which occur consecutively?</p>
  
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-09-27T07:07:02.243Z
Comments.Text: I don't think you fully understand how the Swiss system works. If Hou Yifan was matched with another woman in the first round, then they were in *different* halves of the elo pool. She gets the exact same treatment as all the other GMs from her half (I'd call that equality).
Comments.UserDisplayName: Annatar
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Comments.CreationDate: 2017-09-27T07:09:31.960Z
Comments.Text: In fact, the upper half is expected to win their games against the lower half, and are then matched against each other because they have the same score. Assuming that the frequency of female GMs is higher in the lower than the upper half (your argument about mean of population), she has a *lower* chance to play against another woman in the second round already.
Comments.UserDisplayName: Annatar
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Comments.CreationDate: 2017-09-27T07:15:55.743Z
Comments.Text: @Annatar: as it happens, at Isle of Man, the 1st round was paired completely at random. The rest is Swiss as usual.
Comments.UserDisplayName: RemcoGerlich
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-09-27T07:18:40.140Z
Comments.Text: @RemcoGerlich Okay, interesting. Random distribution still sounds like equal chances, though.
Comments.UserDisplayName: Annatar
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-09-27T07:22:09.020Z
Comments.Text: And of course the question remains of why she would care about the gender of her opponents at all..
Comments.UserDisplayName: Annatar
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-09-27T07:41:25.980Z
Comments.Text: Yes, but I can imagine that if at some point you get the idea that it's done on purpose, and then even though everybody explains that that can't be it _keeps happening_, that messes with your mind even if you didn't care at all before.
Comments.UserDisplayName: RemcoGerlich
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-09-28T13:20:03.327Z
Comments.Text: The real question is whether these pairings are "bad luck" or whether they have been manipulated to somehow "penalize" Hou Yifan. ChessBase has a [report](http://en.chessbase.com/post/hou-yifan-pairings-controversy-investigation) on their website now discussing the Gibraltar pairings, concluding that both SwissMaster and SwissManager would always have given these pairings. So it seems that indeed the stars just haven't aligned for Hou Yifan, and this was just a coincidence. (The first round pairings of IoM are another issue though.)
Comments.UserDisplayName: TMM
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Comments.CreationDate: 2017-09-30T23:15:35.043Z
Comments.Text: Things evened out in the end, with 4 female and 4 male opponents in 8 games, and I doubt Hou Yifan is unhappy with the results. She was just unlucky early on to play against an opponent who was having the tournament of her life (Nino Batsiashvili).
Comments.UserDisplayName: TMM
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-10-02T18:59:15.690Z
Comments.Text: @Annatar I don't think you get how statistical distributions work, look up two distributions with two different means, and come back and let us continue the discussion.
Comments.UserDisplayName: Michael Chukwuma Mkpadi
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-10-02T20:07:17.760Z
Comments.Text: @MichaelChukwumaMkpadi If you look up what "non-deterministic" means..
Comments.UserDisplayName: Annatar
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-10-02T20:09:51.420Z
Comments.Text: @MichaelChukwumaMkpadi Don't try to ridicule people if you have no idea about basic stuff yourself. It makes *you* look silly, not me.
Comments.UserDisplayName: Annatar
Tags: <software><tournament><fide><swiss-pairing>
Title: Why can't FIDE use a Non-Deterministic Gender Neutral Swiss Pairing system?
ThreadText: # Why can't FIDE use a Non-Deterministic Gender Neutral Swiss Pairing system?
  
  (Asked by: username_0 on 2017-09-27)
  
  I have been following the controversy surrounding the pairings of Hou Yifan at the IOM chess tournament 2017. She was paired with 4 consecutive female players, this is following her last open swiss tournament outing in Gibraltar where she was paired with 7 female players from 10 pairings, including round 1 - 4 consecutive female-female pairing as in IOM 2017.
  
  The question is can we not design a simple non-deterministic swiss pairing system that does not penalise the "outliers" of the female population of players? It is clear that rules make it more likely for Hou Yifan to be paired with women as there is an elo gap in mean the population of male elite GMs and female elite GMs and the lowest elo on the highest score and highest elo on lowest score pairing pattern used increases the likelihood of these gender-specific pairings. Any ideas?
  
  Surely we can create opt out for gender pairings which occur consecutively?
  
  **Tags:** software, tournament, fide, swiss-pairing
  
  > **Comments:**
  > **username_1**: I don't think you fully understand how the Swiss system works. If Hou Yifan was matched with another woman in the first round, then they were in *different* halves of the elo pool. She gets the exact same treatment as all the other GMs from her half (I'd call that equality).  
  > **username_1**: In fact, the upper half is expected to win their games against the lower half, and are then matched against each other because they have the same score. Assuming that the frequency of female GMs is higher in the lower than the upper half (your argument about mean of population), she has a *lower* chance to play against another woman in the second round already.  
  > **username_2**: @username_1: as it happens, at Isle of Man, the 1st round was paired completely at random. The rest is Swiss as usual.  
  > **username_1**: @username_2 Okay, interesting. Random distribution still sounds like equal chances, though.  
  > **username_1**: And of course the question remains of why she would care about the gender of her opponents at all..  
  > **username_2**: Yes, but I can imagine that if at some point you get the idea that it's done on purpose, and then even though everybody explains that that can't be it _keeps happening_, that messes with your mind even if you didn't care at all before.  
  > **username_3**: The real question is whether these pairings are "bad luck" or whether they have been manipulated to somehow "penalize" Hou Yifan. ChessBase has a [report](http://en.chessbase.com/post/hou-yifan-pairings-controversy-investigation) on their website now discussing the Gibraltar pairings, concluding that both SwissMaster and SwissManager would always have given these pairings. So it seems that indeed the stars just haven't aligned for Hou Yifan, and this was just a coincidence. (The first round pairings of IoM are another issue though.)  
  > **username_3**: Things evened out in the end, with 4 female and 4 male opponents in 8 games, and I doubt Hou Yifan is unhappy with the results. She was just unlucky early on to play against an opponent who was having the tournament of her life (Nino Batsiashvili).  
  > **username_0**: @username_1 I don't think you get how statistical distributions work, look up two distributions with two different means, and come back and let us continue the discussion.  
  > **username_1**: @MichaelChukwumaMkpadi If you look up what "non-deterministic" means..  
  > **username_1**: @MichaelChukwumaMkpadi Don't try to ridicule people if you have no idea about basic stuff yourself. It makes *you* look silly, not me.  
  
  ---
  
  ## 3 answers
  
  ### Answer by username_2 on 2017-09-27. Score: 8
  
  The current algorithms are deterministic. I have no idea why you would want a *non*-deterministic algorithm. The advantage of the deterministic ones we currently use is that they can be easily done by hand (and were done by hand until quite recently), so if a TD changes them manually that can be detected.
  
  Gender of the players is not an input to the algorithm at all. It does not play a role whatsoever.
  
  Hou Yifan had a very unusual draw in this year's Gibraltar and the first four rounds of Isle of Man; but that's just a coincidence. Something like that has never been noticed with any other women or other tournaments or other years.
  
  > **Comments:**
  > **username_2**: That's a tautology... what's the advantage?  
  > **username_2**: Yes, I know what the word means. A deterministic system always has one clear next step and will always lead to the same output given the same input, a nondeterministic system doesn't. Hou Yifan didn't ask for a non-deterministic one, and so far it's always been seen as an essential feature that the algorithms used must be deterministic, so it can be easily checked that the pairings haven't been tampered with. Hou Yifan suspected tampering, so she would be very much in favour of that. You are the first one I ever hear who wants a nondeterministic algorithm, and I'm asking for a reason _why_.  
  > **username_2**: Tampering is a big problem because organisers try to give their local boy who is trying for a GM norm easier pairings, or just their friends. If the algorithm were non-deterministic, they could always claim it was just randomness. Deterministic is fairer, the same rules for everyone, all the time.  
  
  ---
  
  ### Answer by username_4 on 2017-09-28. Score: 3
  
  > Surely we can create opt out for gender pairings which occur
  > consecutively?
  
  Yes, we could. We can make whatever rules we like, after all. But I don't think we should.
  
  Such a rule would have to come at the expense of some other pairing rule. We currently have rules that players cannot play each other twice, that players with equal scores should play each other, that colors should be equalized, etc. Which of the existing rules are less important than equalizing which gender a player will play?
  
  Such a rule would also imply that playing females is somehow undesirable, or gives an inherent advantage or disadvantage compared to playing males with the same rating. I don't think these are views FIDE wants to encourage.
  
  And any rule that makes things "non-deterministic" makes it harder for FIDE to verify that the pairings were not manipulated. (If we did have such a rule, why would it not be deterministic?)
  
  > It is clear that rules make it more likely for Hou Yifan to be paired with women as there is an elo gap in mean the population of male elite GMs and female elite GMs and the lowest elo on the highest score and highest elo on lowest score pairing pattern used increases the likelihood of these gender-specific pairings.
  
  First of all, people with "highest" and "lowest" scores are very unlikely to play each other. Perhaps you meant "higher" and "lower".
  
  Second, there are pairing rules about minimizing the number of people who get the same upfloat/downfloat as the previous round, or two rounds ago, so while this may be a factor for some players, it won't happen every round, or even every other round.
  
  Third, in both Gibraltar and Isle of Man, she did not float (in either direction) in any of the rounds, so this was pretty much irrelevant. It was sheer luck that she was paired with women.
  
  > **Comments:**
  > **username_0**: The opt outs for people in the same team, federation and family. An opt out for players of the same gender is not as silly as it sounds since most women play in a gender specific tournaments and have not got the same or similar population spread as the open tournaments. That is the reason for this opt out. Think approximation to the normal distribution of two populations with different means.  
  > **username_4**: Did those two tournaments accept opt outs for people in the same team/federation/family?  I'm guessing not, as that would have affected things in the report on Gibraltar pairings that username_3 referenced in his comment.  
  
  ---
  
  ### Answer by username_5 on 2017-09-28. Score: 0
  
  > The question is can we not design a simple non-deterministic swiss
  > pairing system that does not penalise the "outliers" of the female
  > population of players?
  
  What you are saying is sexist and very offensive. You are saying that when Hou Yifan is paired against other female players she is "penalised".
  
  It is correct and fair that the pairing systems are required to be gender neutral.
  
  Your suggestion that -
  
  > Surely we can create opt out for gender pairings which occur
  > consecutively?
  
  offends against one of the basic principles laid down in the [General handling rules for Swiss Tournaments](https://www.fide.com/fide/handbook.html?id=84&view=article) in the FIDE Handbook -
  
  > A. Pairing Systems
  >
  > ...
  >
  > 5 It is not allowed to alter the correct pairings in favour of any
  > player.
  
  > **Comments:**
  > **username_0**: I would be grateful if you did not resort to personal comments here. I am free to ask a question here without being accused of being sexist and being offensive. The question is about gender. If Hou Yifan didn't have a problem with her pairings I would not have posted this question. Is Hou Yifan sexist for wondering if her pairings of 4 consecutive females in two consecutive opens is truly objectively by non-gender biased rules or subjective or manipulated in some way. Is she sexist? I think not so please do not accuse me of being sexist.If questions about gender offend you then don't read them  
  > **username_4**: "Is Hou Yifan sexist for wondering if her pairings of 4 consecutive females in two consecutive opens is truly objectively by non-gender biased rules or subjective or manipulated in some way." - It was perfectly reasonable for her to wonder, as such pairings are unlikely.  But resigning in protest when things were *verifiably* not manipulated was not reasonable.  
  > **username_0**: Totally agree @DM. I wonder why a lot of people think my question implies the FIDE laws are at fault or the organisers or software are to blame. FIDE Laws work and the organisers and pairing software are blameless. Hou Yifan is to blame for assuming a non-bias statistical trial like a swiss tournament pairing system is biased. I am asking intellectually what can be done to take it beyond all doubt. It is a question and I'm only asking it. I have a right to ask any question, right?  
  > **username_3**: @Michael FWIW my comment was aimed at username_5. (My previous comment saying this answer is offensive was removed, presumably because Brian thought my comment hurt his feelings. Apparently Brian is the only one allowed to offend others here.)  
  > **username_3**: @DM You are assuming Hou Yifan also knew this. At the time she likely did not know these pairings are verifiable, and that verifying this would show the pairings were not manipulated. (If she did, I am sure she would not have made a big deal out of it.)  
  > **username_4**: @username_3 Obviously she didn't know, but someone of her standing should have done some research before throwing accusations around.  Pairing rules are easily available online.  
  
  ---
  
  