The position of the score in the results of a leaderboard search.
- iOS 4.0+
- macOS 10.8+
- tvOS 9.0+
- watchOS 3.0+
The value of this property is only valid on score objects returned from Game Center. The
rank property represents the position of the score in the returned results, with
1 being the best score,
2 being the second best, and so on.