air quality policy

Australian Open organizers said Friday air-quality conditions will be rated on a scale of 1 to 5, with 1 being "good playing conditions," and 5 representing conditions so bad that competition will be suspended — but even then, not immediately. Instead, the policy says the break will arrive only after a set reaches an even number of games or an in-progress tiebreaker is completed.

And then the policy goes on to say: "At any point the Referee may decide to suspend, maintain or resume match play in accordance with this policy and at his or her absolute discretion, taking into account advice from onsite medical experts, visibility, forecast changes to weather conditions and any other factors deemed relevant to the overall assessment of air quality."