I don't know the logic they use to come to the conclusion that a 6 point jump is very "suspect," but it seems bogus to me. The first time I took the ACT I think I made a 22. The second time I made a 28, and it was because I actually studied before taking it unlike the first time. I think it is not unreasonable to assume that most high school kids, especially ones concerned more with football (and being recruited and taking visits to school and making a decision where to go) than academics, may make a low score on their first try, then put more effort into studying and show drastic improvement. In fact, IMO, that explanation is more probable than that they are cheating to get a 6+ point bump.