[blml] Swiss Teams formats [SEC=UNOFFICIAL]

[richard.hills at immi.gov.au]

Herman De Wael:

>Richard,
>
>I too find it an interesting idea.

[snip]

>We are currently looking at ameliorating the Final of the Flanders'
>Cup, which is currently a Swiss over 9 matches of 6 boards, with 64
>teams! The better players are starting to complain that it is becoming
>a lottery. Maybe a change such as this one could help! We don't really
>want to change the number of teams nor the length of the final.

Richard Hills:

Okay, I suggest keeping the length of the final constant, at 54 boards,
but changing from a Swiss with 9 matches of 6 boards each, to an
Accelerated Swiss with 6 matches of 9 boards.

One part of Wayne Burrows' analysis that I am confident is true is that
an Accelerated Swiss has a greater impact over a six round event than
it has over a nine round event.  (Wayne and I merely differ on whether
an Accelerated Swiss has a beneficial impact, and what "beneficial"
means.)

Accelerated Swiss movement details are attached.

Best wishes

Richard James Hills, amicus curiae
National Training Branch, DIAC
02 6223 9052

Accelerated Swiss

Introduction

Fifty years ago, most chess tournaments used the round-robin movement. As
chess grew in popularity, time available for events made round-robin
movements less feasible. Therefore, chess administrators progressively
switched to a movement that approximates the round-robin movement, the
Swiss movement.

At the end of a Swiss, the results of the top few and bottom few
contestants are relatively accurate. That is, had the same event been held
as a giant round-robin, those top few and bottom few teams would have
finished in closely similar places.

However, the placings for the middle contestants at the end of a Swiss are
highly random compared to what their placings would have been in a
hypothetical giant round-robin. A dominant factor is the luck of the draw,
and the timing of a contestant's victories.

Each additional round of a Swiss expands the size of the top few and bottom
few groups, and reduces the size of the random middle group.

To gain an extra round of Swiss accuracy, chess administrators seeded their
Swisses, ensuring that the best players in a chess tournament played
against each other as soon as possible.  However, as the numbers of
contestants in chess tournaments increased, even seeded chess Swisses began
to produce less meaningful results for the number of rounds available.

Therefore, to add a further round of accuracy, chess administrators
introduced the Accelerated Swiss movement.

This article describes how the Accelerated Swiss movement has been adapted
for a bridge teams event, using the WBF victory point scale.

Executive Summary

The Accelerated Swiss has two advantages:

1.  Technical – A seeded Swiss has an accuracy advantage over an unseeded
Swiss equivalent to an extra round.  An Accelerated Swiss gains a further
round of accuracy, reducing the chances of a mediocre team “swissing
through the field”.

2.  Psychological – A seeded Swiss is unpopular among some weaker teams due
to the first-round “bloodbath”, where their teams get annihilated by
Klinger, Marston etc.  There is no bloodbath in the first round of an
Accelerated Swiss, as the top seeds and bottom seeds are paired within
their own group.

Procedure

Part A – Overview and Round One draw

1.  Seeding – Seed the entire field.

2.  Temporary carry-forward – Give the top 50% of the seeds a temporary
carry-forward of 10 vps.  This carry-forward is used in determining the
draw for both Round One and Round Two.  After finalising the draw for Round
Two, remove all of the temporary carry-forwards.  The draw for Round Three
and subsequent rounds will be a normal Swiss draw based on earned vps.

3.  Round One draw – The top quarter of the field is drawn against the
second quarter of the field; the third quarter of the field is drawn
against the fourth quarter of the field.

Example 1: A draw where the field (100 teams) is divisible by 4:  1 vs 26
                                                            2 vs 27
                                                            ....……
                                                            24 vs 49
                                                            25 vs 50
                                                            51 vs 76
                                                            52 vs 77
                                                            ……….
                                                            74 vs 99
                                                            75 vs 100

Example 2: Modified draw where the field (98 teams) is not divisible by 4:
                                                            1 vs 25
                                                            2 vs 26
                                                            ……….
                                                            23 vs 47
                                                            24 vs 48
                                                            49 vs 50
                                                            51 vs 75
                                                            52 vs 76
                                                            ………..
                                                            73 vs 97
                                                            74 vs 98

Part B – Round Two draw

1.  Divide the field into three groups:

–     Group 1 is initially defined as those teams with 35 vps to 26 vps
(top seeded winners)
–     Group 2 is initially defined as those teams with 25 vps to 15 vps
(top seeded losers + bottom seeded winners)
–     Group 3 is initially defined as those teams with 14 vps to 0 vps
(mostly bottom seeded losers + a few top seeded annihilated teams)

2.  Modify Group 1:

–     If there are an even number of teams in Group 1, no modification is
necessary
–     If there are an odd number of teams in Group 1, add the bottom-seeded
team with the biggest 25 vp result to Group 1

3.  Modify Group 2:

–     Group 2 should have exactly 50% top seeds and exactly 50% bottom
seeds
–     Transfer surplus teams from the lower end of Group 2 to Group 3

4.  Round Two draw for modified Group 1:

–     Group 1 is paired within itself in normal Swiss fashion

5.  Round Two draw for modified Group 2:

–     Group 2 is paired within itself in normal Swiss fashion, but
–     constraint: each pairing must be a top seed versus a bottom seed

6.  Round Two draw for modified Group 3:

–     Group 3 is paired within itself in normal Swiss fashion, but
–     constraint: top seeded teams must not be paired against each other

Important Notice: If you have received this email by mistake, please advise
the sender and delete the message and attachments immediately.  This email,
including attachments, may contain confidential, sensitive, legally
privileged and/or copyright information.  Any review, retransmission,
dissemination or other use of this information by persons or entities other
than the intended recipient is prohibited. DIAC respects your privacy and
has obligations under the Privacy Act 1988. The official departmental
privacy policy can be viewed on the department's website at www.immi.gov.au
See: http://www.immi.gov.au/functional/privacy.htm