A gear (cog wheel) with seven teeth is taken out of service and
teeth examined for wear. Only adjacent pairs of teeth may be compared,
but any given pair may be compared by a number of people, each of whom
indicates which tooth they believe to be more worn.The dataset is of the form of a seven-by-seven matrix, one column for
each tooth. Each row consists of precisely two non-NA
entries,
say in columns A and B. The entries indicate the number of times an
observer prefers (that is, judges to be more worn) tooth A and
tooth B.
The board has a single degree of freedom.