Essentials of Round Robins pt. 2

Logistical requirements

Facilities,
Equipment, and Staff

Consider a field containing n
teams. All games are played by pairs of teams.
Therefore, the greatest number of games that may occur at a
given time when n is even 
is n/2. When n is odd,
meanwhile, an odd number of teams cannot play a given game;
rounds in which a team does not play are called the bye
rounds of a given 
team. The maximum number of games
that can occur at once when n is odd is (n-1)/2. Every
game requires one room in which to hold it, one set of
questions, one 
buzzer, one clock in timed formats, at
least one scoresheet, one moderator, and, if possible,
one scorekeeper. Therefore, when preparing for a
round robin of n 
teams, one should first guarantee
for the length of the round robin n/2 rooms, question
sets, buzzers, clocks when necessary, scoresheets,

moderators, and scorekeepers; (n-1)/2 of each of these items
is necessary when n is odd.

Throughout this
tournament, it is assumed that the above is available
throughout the round robin. For exceptions, see the section
Constrained Cases.

Time & number of
rounds

Generally, the time a round robin requires to be played is
equal to the sum of the lengths of all the rounds, plus
any transition time between rounds. Where T is the

total time consumed, t is the expected length of a
round, r is the number of rounds, i the number of
iterations, and m is the transition time, T = ir(t + m).
Allot T time 
on your schedule. It is standard
practice for m to be considered a part of t. Draft your
schedule, then, in ir increments of t.

Consider
again a field containing n teams. In one iteration, a
given team will play every team except itself only
once; therefore, each team will play n-1 games. This is

common to all round robins.

There are now four
cases to consider, based on two variables: 1. there are
an odd number of teams in the field, and the
questions for each round are submitted by 
each team; 2.
there are an odd number of teams in the field, and each
team is blind to all the questions to be used; 3.
there is an even number of teams in the field, 
and
the questions for each round are submitted by most or
all teams; 4. there is an even number of teams in the
field, and all teams are blind to all
questions.

Case 1 is the most frequent situation for invitational
tournaments. Each team cannot play on its own questions.
Meanwhile, all matches occur between pairs of 
teams;
therefore, in any round, an odd number of teams must not be
playing; assuming a sufficient number of rooms, only one
team cannot play in a given round. 
These two
constraints correspond neatly; therefore, the questions a
team submits should be played on in the round that
that team does not play. Since a team (in 
general)
submits only one round of questions, has only one bye
round, and plays each opponent once, we find that one
iteration of a submission round robin 
containing n
teams requires n rounds, where n is odd.

Case 2
is identical to case 1, except that teams do not
submit questions. However, the same constraint requiring
that matches be played only between pairs of teams

persists. Therefore, each team still must receive a bye
round, even though its questions are not being used.
>From examination of these two cases, we find that when

n is odd, a round robin for a field of n teams
requires n rounds.

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