[blml] Swiss Teams formats [SEC=UNOFFICIAL]

[richard.hills at immi.gov.au]

Herman De Wael:

[snip]

>I have once read that studies had shown that the first round
>seeding in a (bridge) swiss has no specific influence on the
>outcome, so this accelerated idea would only have some
>influence because of the way the second round is paired up.
>I don't think I'll bother, then.

Richard Hills:

In seeded teams events run under the knockout principle, such
as the ACBL Spingold or Vanderbilt, if there is a perfect
entry of 64, then the draw for the first round is:

1 vs 64
2 vs 63
3 vs 62
4 vs 61
.......
29 vs 36
30 vs 35
31 vs 34
32 vs 33

In Wayne Burrows' simulation, he found that such a first round
only seeded draw (as opposed to an Accelerated Swiss seed draw
for two rounds) did have a persistent effect on the outcome if
there was only a small number of rounds in this Seeded-But-Not-
Accelerated Swiss.

This is because a top seeded team is given a boost towards
their "rightful" place at the top of the field by being given
a very weak first-round opponent, a bottom seeded team is
given a shove towards their "rightful" place at the bottom of
the field by being given a very strong first-round opponent,
and a middle seeded team is given a force towards their
"rightful" place in the middle of the field by being given a
near peer as their first-round opponent.

In Australia it is traditional that most Swisses are seeded,
but a less effective formula is used:

1 vs 33
2 vs 34
3 vs 35
4 vs 36
.......
29 vs 61
30 vs 62
31 vs 63
32 vs 64

The premier teams event in Australia, the NOT, has a Swiss
qualifying of 14 rounds (20-board matches).  Due to the huge
length of the qualifying, a first round draw based on seeding
within the field is unnecessary.

(But nowadays, with two fields split between two venues, seeding
to ensure the top teams are divided evenly between venues is
required.)


Best wishes

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

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