What is the difference between the Full Indesit ATP Race and the Indesit ATP Rankings?

Question

Roddick is fourth in one of them and sixth in the other.

Answer 1

Full Indesit ATP Race is a race starts in January of the calendar
year, and concludes at the end of the season. The Indesit ATP
Rankings is basically an accumulation of points over the most recent 52 weeks of play, i.e. from October 2, 2005-October 1, 2006 would be an example of the most recent 52 weeks. The Indesit ATP Rankings is the entrysystem style of rankings that you're used to seeing in the calculation of the rankings, and these are the real rankings in my opinion, since it is always the same constant, 52 weeks. The ATP Race is basically taking all the points a player earns since the beginning of the current season.
I hope this explanation helps. The Champions Race always starts at the beginning of the tennis season, and concludes at
the end of the season. The entrysystem rankings are a 52 week
continuous flow system.

Answer 2

The Indesit ATP "2006 Race" only takes rankings points for that whole year, while the Indesit ATP "Rankings" take in rankings points for 18 best tournament results continuously for the past 52 weeks (not from the start of the year, any past 52 weeks.)

There are two systems in place because if there was only the Race system, then seeding would not be proper, especially at the start of the year. For example, if there was only the race, Baghdatis would be seeded 2nd in the tournaments that followed the 06 Australian Open, but using the continous, or "rolling" system, his seeding would be much lower because his best 18 results were not as good as another player.