Chase for the championship
I don't play the fantasy league and don't know much about it, but I do know about the Nascar "Chase" It was implemented to deviate from the traditional points-based championship because it was difficult for less-than-diehard fans to follow. It was implemented for the benefit of the fans, not the participants. Of course the participants went along with it because more/happier fans means more money. Hot Wheels racing does not have a whole lot of fans to worry about pleasing. I can't even get participants! Plus, in Nascar the points-leader gets a set amount of "chase" points which decreases down to the last eligible team. They don't have to start from zero which would never fly after a whole season and a gazillion dollars. I never liked the idea and it hasn't delivered excitement in my opinion.
Apples and oranges!
Maybe the word "Chase" isn't a good idea if people try to relate it to NASCAR. IMO, people who participate in the Fantasy League would be more likely to stay interested throughout the season if staying in the top 16 meant something. The ones not making it into the "whatever it is called" shouldn't be put off by having to sit out just 2 races (or a small number, whichever might be decided).
I haven't been here long but I do like the idea of two championships per season (season champ and chase champ). In my mind the chase is motivation to keep a player involved the entire season. With the chase, players that realize they have no chance of being near the top of the chart at the end of the season would have a reason to stick around hoping they make the top 16. Like Brian said, a tie-breaker system would have to be developed. Just to throw one out there, the first tie-breaker should be how many tournaments the player entered in the given season.