Soccer Is Harder than Football.
Jan Christensen, Anders Nicolai Knudsen, and Kim S. Larsen.
International Journal of Foundations of Computer Science. Accepted for publication.
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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