We have had a few different concepts of routing requirements:
1) One landing on each of the six continents
2) Two landings on each continent at least X miles apart (the X miles is usually set to ensure that at least one landing between the two distant landing is necessary unless a wildcard is used). Cannot make the distance requirement too far because Europe is the smallest continent.
3) One landing in a specific country on each continent, along with the X miles requirement.
4) Gateway airports - this actually is a variation of the London-Melbourne race required stops. And should anyone have an actual real Around the World Race - you know there would be required airports.
We have also had some additional requirements:
1) North and South latitude requirements - one landing or two X miles apart
2) Below Sea Level and Above X elevation requirements
3) Water Landings
4) We have also considered some additional different requirements - One or Two major commercial airports, One or Two military airports, One or Two airports with max runway length shorter than X feet/meters
Good, Bad, Too complex, Just right?
Most importantly - do pilots want different requirements each year, or do they want the same from year to year?
Corridors vs Wild Cards? Which is better?
I'll be honest, I have about run out of ideas/ options for different corridors.
Continents - we have had complaints about the complexity of the definition of continents and 'the primary land mass'
We have separated the contients as the Panama Canal between North and South America, and the Suez Canal between Africa and Asia. Europe/ Asia is difficult. I think we all agree that Turkey is Asia. Some folks are still vehement that North America means in the countries of Canada and the United States, maybe Mexico - certainly not Panama, Costa Rica and other nations in Central America.
Some would have KJFK and KLGA as part of North America but they are on an island - so if they are part of North America, then what about EGLL and Sicily or Singapore? It is much easier to just say on 'the primary land mass'.
We do want to hear your opinions - we will tell you of some quesitons, problems, requests we have had in the past.