Soccer Is Harder than Football.
Jan Christensen, Anders Nicolai Knudsen, and Kim S. Larsen.
International Journal of Foundations of Computer Science, 26(4): 477-486, 2015.
It is known that deciding whether or not a team in a soccer tournament in progress can still win or, more generally, can obtain a certain position is NP-complete. We show that deciding whether or not a team is guaranteed a certain minimum position is coNP-complete. We also show that deciding with regards to goal difference, the standard tie-breaker for teams having the same number of points, whether or not a team can reach a certain position is NP-complete.

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