I keep thinking back to "Genius Denied" when I think about grade skipping. Grade placement should be where the child fits in, both academically and to some extent socially, but "every child deserves an appropriate education". Grade divisions should be viewed as imaginary lines, with the idea of "does the child fit here?". All of my kids have said, "I am so glad I skipped", when they see the work level and maturity of the kids a grade behind. Would they do that if they were skipped again? Probably, and it might happen at some point, but if they can be accommodated presently, then the fit is adequate.