Originally Posted by Al B

It's the same mileage as an air segment, regardless if a Star partner serves the city pair or not.
Where more than one mileage amount exists between two city pairs, you take the lower of the two.
Where no fares have ever been filed between a city pair and a mileage amount does not exist, you take the shortest connection you can find that has mileage listed between origin and destination via an en-route intermediate port.