  Since March 2020, the environment surrounding football has changed
dramatically because of the COVID-19 pandemic. After a few months' break,
re-scheduled matches were held behind closed doors without spectators. The main
objective of this study is a quantitative evaluation of ``crowd effects'' on
home advantage, using the results of these closed matches. The proposed
analysis uses pairwise comparison method to reduce the effects caused by the
unbalanced schedule. The following conclusions were drawn from the statistical
hypothesis tests conducted in this study: In four major European leagues, the
home advantage is reduced in closed matches compared to than in the normal
situation, i.e., with spectators. The reduction amounts among leagues were
different. For example, in Germany, the home advantage was negative during the
closed-match period. On the other hand,in England,statistically significant
differences in home advantage were not observed between closed matches and
normal situation.
