Apply a rule of thumb to outliers generally isn't appropriate. While it might be true that generally success rises 2% for every 10 SAT points, that doesn't necessarily mean it applies to Harvard and U Maryland. Especially due to grade inflation. 15 years ago, flagship state schools still harshly curved science/engineering classes to weed people out. While Harvard give you a gentleman's B+.
My kid is attending a flagship state school now. His school still very much uses a harsh curve to weed out. A B- keeps you on the track to success in your major.
If he decides to go to grad school, he'll be screwed even though he's been on the plus side of the curve in all of his classes so far.
Grad admissions committees vary quite a lot from program to program, in terms of how they value different admissions criteria. if your kid is interested in research don’t let grades faze them. Demonstrated ability to think independently and write clearly is much more important IMO, at least for PhD work
