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Eric Peterson, PhD., Slovakia
GM Peter Heine Nielsen is of course completely correct in his protest. The tiebreak
method used by the ECU in the European Championship is completely absurd and
random. Someone did not think it out carefully. The absurdity of the ECU method
can be concisely shown by: "If you beat the highest-rated opponent you
faced, this is horrible for your tiebreaks. But if you lost to your highest-rated
opponent, this is a tremendous benefit." Obviously a tremendously flawed
system.
David Hodge, UK
As a mathematician I was pleasantly surprised to see a very nicely written critique
by PHN of how ridiculous the tie-break system implemented is/was. And why the
tie-breaks calculated should be scrapped and redone properly. It is clear to
me, and should be clear to anyone who sees what has happened that what has been
implemented is not a "performance rating" in the sense that anyone
would accept it. Furthermore, as Peter points out (though he wrote it less persuasively)
there is even a serious problem with the rules as they are written as the tournament's
eventual second place competitor would have won the tournament if only his first
round opponent (whom he beat) had been rated two points lower!! If his first
round opponent was rated one point lower then God knows what the organizers
would have done because they would have had to choose which of his first two
games to delete, the first one or the second one. The choice would result in
deciding who won the tournament. I guess in the scenario that their "performance
rating" was uncalculable they would have moved onto tie-break system B.
This is also ludicrous due to the fact that the "system" they used
isn't even a valid and comprehensive system to cover normal possibilities (like
two players having the same rating). One would normally only consider a "second"
tie-break system if the players drew on the first system, in this case they
would have had to move onto the "second" tie-break because the first
one isn't even defined! Maybe Judit would even have won! I would appreciate
to hear if there is any precedent for organizers ever to have used such a nonsense
system before. There is certainly no way this rule could ever be used again
to decide tie-breaks, now that organizers realize what it does, and it would
only be fair (if possible) to recalculate performance ratings in a normal fashion.
Still ignoring top and bottom ratings as the rules intended is fine, as long
as you don't actually pretend the games never happened too!
GM David Navara, Prague, Czech Republic
I read the interesting article from GM P. H. Nielsen on the tie-breaks used
at the European Individual Championship. I think that his proposal is much better
that the tie-break which was used, but still I think that I have a better idea.
I agree with the objections against the actual tie-break rules, which GM Nielsen
summed up. Nevertheless, I believe that his proposal is also not completely
fair. If someone beats a player rated 1400 in the first round, why should this
game count in his percentage without influencing the average rating of his opponents?
I think that it would have been much better to take the "classical performance" and then to remove all the won games of the player, which deteriorate his performance. I believe that such a rule would have helped to provide relatively fair tie-break rules. It should ideally be supplemented with a similar rule, which would not count into the performance the games, which a player lost, but which improved his performance. (I believe that such cases would have been extremely rare at the tournaments like the European Individual Championship. It could be useful in cases when one opponent of a certain player has significantly higher rating than the remaining opponents of the very same players.)
The only difficulty with adding this complementary rule is that the order of applying both rules would need further specification, because it could happen that the different orders of application of these two rules could produce different results because in one case it could be better to cross out some game, whereas in the other one it could be better to keep it. (I could provide some advice how to calculate the performance then.)
Nevertheless, it should not be too difficult to calculate the modified performance on this basis. It would have been very logical, because no win could have deteriorated player's performance and no loss could have improved it. It also should be relatively simple to calculate this. My proposal is just a sketch and needs to be completed, but I believe that it could provide a relatively fair way how to calculate the performance. It is not ideal, but I cannot see any better way.
GM Dr John Nunn, Lyne, England
It's interesting how complicated this discussion has become. The problem is
the use of 'performance ratings'. Instead it's much simpler just to use the
average of the opponents' ratings. If one player has scored 7/9 against an average
of 2500 and another player has scored 7/9 against an average of 2520 then the
second player should be ahead of the first on tie-break. It's simple and it
doesn't depend on the player's own rating.
At first sight this is equivalent to using 'performance ratings' but that isn't
the case due to the 400-point rule, and especially not if one starts eliminating
certain results from the procedure. It also has the advantage that it is independent
of the FIDE procedure for calculating performance ratings, which is of course
subject to change.
I accept the point that if one player is unlucky enough to be paired against
an opponent with a rating of 1200 in the first round, then he will effectively
have dropped half a point because he will always be last on tie-break, so it
makes sense to drop the lowest rated opponent from the calculation.
Paul Lillebo, Asheville, NC, USA
Shouldn't someone make the obvious point that predicting outcomes is NOT a purpose
or function of Elo's rating system, or of any useful rating system. Sonas' silly
contest to find a system that will "outpredict Elo" has no value for
chess. The Elo system does fairly well what it's supposed to do, namely report
how strongly the player has played, with emphasis on more recent games. Whether
the player's past results are predictive of future results is a whole different
question, independent of the rating system unless the rating only takes into
account the player's current form, say the past few months. Understandably,
elite tournament organizers would love to know how strongly a player will play
a year from now, but I'm afraid they'll just have to continue to trust their
instincts.
Eddy Fong, Kampar, Malaysia
Perhaps they could consider removing the win against the lowest rated player
and the loss against the highest rated player, and calculate the performance
rating (Thompson method) based on the set of nine remaining games. This seems
a fairer method. All players affected have a point removed. If all games are
drawn, then the respective drawn games would be used instead of the win and
loss. Only other issues is where a player has one win (with no loss) or one
loss with (no win).
Iman Khandaker, Watford, UK
It is bizarre to the point of perversity, that a tie-break method should discard
actual RESULTS. Discarding highest and lowest ratings makes more sense –
though simpler measures like fewest draws or most wins with black seem equally
reasonable.
Nielsen protests ECU performance calculations |
Sonas: Assessment of the EU performance calculation
|
The Elo rating system – correcting the expectancy tables 30.03.2011 – In recent years statistician Jeff Sonas has participated in FIDE meetings of "ratings experts" and received access to the historical material from the federation archives. After thorough analysis he has come to some remarkable new conclusions which he will share with our readers in a series of articles. The first gives us an excellent overview of how the rating system works. Very instructive. |