swiss

The swiss system is a fairly complicated pairing system(books have been 
written on it).  Here is a short summary.  For the first round, the players 
are ranked by rating.  The top player of the top half plays the top player
of the bottom half, the #2 player from the top half plays the #2 player 
from the bottom half, and so on.  Colors alternate for the top players.  A
sample first round pairing for an 8 player tourney would be 1-5, 6-2, 3-7, 
8-4.  After each round, the players are sorted again.  This time, they are 
sorted by score in the tourney(1.0 for each win, 0.5 for each draw, 0.0
for each loss).  The swiss algorithm mentioned above is then applied to each 
group.  As the tourney goes on, the number of groups(and thus the number
of groups with an odd number of players) grows.  There are many techniques 
used to pair players that are at least very close in score while avoiding
having two players play each other more than once and giving very
lopsided color distribution(for example, having 4 whites and one black in
a 5 round tourney) which are beyond the scope of this short summary.  To 
sum up, you play people who are doing close to as well (or poorly) as you
in the tourney, you play close to an equal number of games with white as
with black, and you don't play the same player twice.  Mamer does its
best to make good swiss pairings, but occasionally it will produce some
odd pairings.

[Last modified: March 8, 1999 -- toddmf]
