There are two ways that Worldperk miles are calculated as mentioned ealier on this topic:

1) Statue Air Miles for flights with a stop and no change of Flight number.

2) Statue air miles with a minimum of 500 credited flight miles (even if the flight is actually less than 500 statue miles)

Senario #1:

If you were flying CMH/DTW/FNT on direct flight from CMH with a stop in DTW you would earn 500 Worldperk Miles.

Senario #2:

If you were flying CMH/DTW/FNT with a change of planes and each segment had a different flight number you would earn 1000 Worldperk miles.

RC