### Tournament Disqualification - host unreachable (after 3 connection retry attempts) - connection lost (and could not be re-established after 3 retry attempts) - response received (but not expected; does not correspond to a request) - invalid greetings JSON - invalid greetings response structure (duck-typing) ### Match Disqualification - request time-out (via request timestamp and response deadline) - invalid choose_turn response JSON - invalid choose_turn response structure (duck-typing) - invalid choose_turn response for the given board state (invalid move)
