# Re: Traviesties in the methods Europeans Use for Pairing Algorithms

• From: Robert Jasiek <jasiek@xxxxxxxx>
• Date: Tue, 06 Sep 2005 09:03:11 +0200

On Mon, 05 Sep 2005 16:24:30 GMT, jazzerciser@xxxxxxxxxxx (-) wrote:
> Europeans can't seem to operate a tournament properly.

Do you draw general conclusions from the one particular tournament TT
Brno?

> Note how Mr. Cornel Burzo was paired against a 3d in Round #3
> after losing one game !

He, #3, was paired against player #2, a 7d, in round 3 and against
player #16, a 3d, in round 4.

After round 3, the following players had these MMS:

final MMS in top
place round 3 group

#1 26 x
#2 26 x
#3 25 x
#4 25 x
#5 25 x
#6 25 x
#7 25 x
#8 25 x
#9 24 x
#10 25 x
#11 24 x
#12 24 x
#13 24 x
#14 24 x
#15 24 x
#16 24
#17 23 x
.... <24

For round 4, this forces the game #1-#2. The even number of players
#3, #4, #5, #6, #7. #8 are available for pairing next, unless all
possible pairings would repair an earlier game of the tournament.
Since the pairing #3-#4, #5-#6, #7-#8 is one such a possibility, all
these MMS25 players have to be paired against each other in round 4.

That #3-#16 was a game in round 4 does not conform to what one expects
from a MacMahon tournament, although "MacMahon" has never been defined
officially so far.

Thank you for pointing out this!

> When Mr. Cho. Seok Bin lost a game he
> was paired against a 6d in Round #5.

final MMS in top
place round 4 group

#1 27 x
#2 26 x
#3 26 x
#4 26 x
#5 26 x
#6 26 x
#7 25 x
#8 25 x
#9 25 x
#10 25 x
#11 24 x
#12 25 x
#13 24 x
#14 25 x
.... <25

In round 5, Cho Seok-bin, #2, might have been paired against one of
#3, #4, #5, #6, if possible. That he was paired against #4 was ok.
(There is no specification for EGF tournaments of how a pairing must
be done if MMS are equal and several opponents are thus available.)

> When Radel Nechanicky
> lost a game he was paired against a 4d.

He was paired down in round 6.

> The problem here concerns
> heavy reliance (incorrect) on the SOS and SOSOS formulations.

Why? Do you know which pairing program was used and with which
parameters? Before one cannot say whether the pairing depended on
tiebreakers at all.

> The column titled "MMS" is not actually MacMahon Score, but
> SOS.

Now you are joking.

> When enough players complain then tournament organizers
> will need to justify what they are doing upon mathematical grounds,

Rather the EGF Rules Commission would disallow pairing programs that
produce non-MacMahon pairings.

> Players are not expected to know mathematics, however the
> tournament organizers who operate pairing programs should be
> accountable to the mathematical arguments and proofs.

As far as it is clear what MacMahon as a system is supposed to do.

> Robert
> Jasiek is perhaps responsible for the European travesties today,
> because Mr. Jasiek has incorrectly argued

No, but because I am a member of the EGF Rules Commission.

> for use of SOS rather
> than counting up the defeat chains in SODOSODOS and so forth
> (getting longer for each successive round).

I have not argued such for producing pairings yet. I have argued about
the final results and favoured MMS only without tiebreakers for the
final results.

--
robert jasiek
.

• Follow-Ups:
• References:

## Relevant Pages

• Re: McMahon Pairing Protocols Standards ( AGA ) -- Draft
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(rec.games.go)
• Re: Traviesties in the methods Europeans Use for Pairing Algorithms
... >> Europeans can't seem to operate a tournament properly. ... I meant to say that Cornel was paired against a 3d in Round #4. ... the following players had these MMS: ... as the pairing algorithm allowed a 3 rank difference too early. ...
(rec.games.go)
• Re: Traviesties in the methods Europeans Use for Pairing Algorithms
... > on the inadequate draw (pairing) system at the Rochester Congress to ... > until the final round, when he was finally paired against a 4dan. ... > leave that to the tournament organisers, ... > top group players are considered by axiom to have equal chances, ...
(rec.games.go)
• Re: McMahon Pairing Protocols Standards ( AGA ) -- Draft
... Surely European tournaments are not unfair after 3rd Round? ... pairing tiebreaker as the first final result ordering tiebreaker. ... should depend upon degree of disorder in the candidate field. ... a tournament progresses. ...
(rec.games.go)
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