4 players, A, B, C, and D play a games in tournament. D lose the 3 matches. A defeat B, B defeat C, C defeat A. Who is the winer?

randomly between A B C

https://www.warlight.net/wiki/Round-robin_tournaments

All the WarLight Wiki has to say is

In the event of a tie at the end of the tournament, the winner is decided by who won when the tied players played each other.

However, that doesn't tell us who could win in a 3 way tie where they're all level. As far as I'm aware, there isn't a tie-breaker beyond that point. Fizzer should probably look into adding further tie breakers for situations like this.

randomly between gnuff and his 2 alts