Now we have central planing - Common Core, which will ensure no one excels.
How so? AFAICS acceleration/grade skipping and AP classes were the main US method for the gifted to excel, to me it seems much more common in the US than many other nations with supposedly high education standards. I think you got it right too, getting them through the basics fast (ie. high shool and bachelor's) will help the gifted more than trying to keep them entertained with extra classes as you effectively hold them back.
Has common core made acceleration more difficult?
First, your question "Has common core made acceleration more difficult?"
Yes because it gives schools the excuse not to do more. Further, Common Core is both less comprehensive and slower. It slows kids down because some of the requirements are pushed back.
For example, according to Pioneer Institute (research paper #65, Common Core Standard): "Overall, Common Core's preparation for Algebra 1 falls a year or two behind the standards in California and high achieving nations." I don't have permission to upload the 60 page report, you can search for them. This is but one of many examples.
That said, I do not promote the idea of skipping grades. It causes two problems in my view: (a) that you did great in addition/subtraction last year doesn't mean you can skip learning multiply/division this year, and (b) upon skipping a grade, students often turn from begin leaders to being followers due to the more mature classmates a year older than the grade skipper.
Instead, I like more comprehensive classes. A great example is (AP) Calculus AB verses (AP) Calculus BC. Both covers almost the same subjects but BC is far more comprehensive than the AB sequence. I prefer a firm foundation more than a wimpy foundation faster.
Compared to TIMSS (Trends in International Mathematics and Science Study), Common Core is dangerously inadequate.
Really? I think the common core math curriculum is too advanced for a comprehensive education. Now of course the whole concept of comprehensive high school curricula is a bit retarded, but I don't see how making it more advanced could make them adequate. Good for the colleges who can cut some maths out of their curriculum I guess, but even more out of touch with the needs of the non gifted.
Yes, really - compare TIMSS side by side with MA/CA and Common Core side-by-side topic by topic, TIMSS A+ countries teaches more topics and teaches them sooner. The math curriculum doesn't even come close to being competitive let alone advanced. Following the standard at its pace, the student would barely get Algebra II done let alone pre-Calc or Calculus.
For the examples below, I use Massachusetts(MA)/California(CA) old standards as they were higher than other States. Again, this is not to say they met their own standard. So don't need to argue regarding actual level reached.
(a) Major topics grade 4 to grade 8TIMSS A+: 16 - 22
MA:/CA: 16-21
Common Core*: 7-15
(b) Slow pace, for example:TIMSS A+, MA/CA's:
finish learning of addition and subtraction for numbers of any size by 3rd grade, multiplication on by 4th grade and division by 5th grade.
Common Core*: Student learn up to 3 digits addition and subtraction, 2 digit multiplication/subtraction. Student are not expected to learn the multiplication table to 100.
*I am using the initial (2010) Common Core standard that States wanting funding must pass legislation to support. That in my layman's view is the legally binding one.
Edit: (added and removed again)
I've said enough about education. I touched on that because some of us are so full of ourselves thinking we are so much smarter. I want to at least inject the idea that we may not be as hot as we think. In fact, I think we are quite behind the 8-ball.