[bill dedman]

A major flaw in using National Records for handicapping cars was that, after awhile, it became apparent to the people who raced a lot, that if they re-set the record, they were shooting themselves in the foot, as it would chip away at their handicap (dial-in) number, so racers who were aware of this would "protect" their record (not lower it) 'til after awhile, National Records became a joke, because so many of them were "protected," and not nearly as quick as they needed to be.

It was called "sandbagging," and still is....

That's one of the reasons the index system was created.