  In most professional sports, the structure of the environment is kept neutral
so that scoring imbalances may be attributed to differences in team skill. It
thus remains unknown what impact structural heterogeneities can have on scoring
dynamics and producing competitive advantages. Applying a generative model of
scoring dynamics to roughly 10 million team competitions drawn from an online
game, we quantify the relationship between a competition's structure and its
scoring dynamics. Despite wide structural variations, we find the same
three-phase pattern in the tempo of events observed in many sports. Tempo and
balance are highly predictable from a competition's structural features alone
and teams exploit environmental heterogeneities for sustained competitive
advantage. The most balanced competitions are associated with specific
environmental heterogeneities, not from equally skilled teams. These results
shed new light on the principles of balanced competition, and illustrate the
potential of online game data for investigating social dynamics and
competition.
