[Joe Wicked]

Wayne,
All of the chase cars got a jump in points to 5000 plus a bonus 10 points for each win they had during the season. Originally it was the top 10, as no one outside the top 10 ever has come back to win it in the last 10 races. They expanded to 12 to widen the competition. With the current points setup even if 13th place won every race, they would not equal the points of any of the Chasers.

I like the idea of them all out there during the chase as it would be a boring race with only 12 cars that are more concerned with what they have to loose vs what they can gain/do. This also means that a bad day (or 3 in a row with Busch) can take you out of the chase effectively. Finishing 12th on a bad day, you will not loose much ground ever.