"This is not about Standard grades in S2," John Wilson said in an interview with The TESS. "Apart from anything else, we don't do Standard grades any more. It is about appropriate courses with appropriate certification. That is what this structure will help us to deliver."
He said the authority's new curricular structure for its seven secondaries, approved last week by councillors, should be seen more as a response to the likely demands of A Curriculum for Excellence than a move to take advantage of relaxations in age and stage regulations.
Mr Wilson said, however: "We have to smooth out the gradient. Currently, kids are treading water at the start of secondary, go on a bit of an incline, and then face a huge increase at Highers."
The council's new approach, which is to take effect in August, will have benefits for all pupils, he said.
The less academic, instead of following an S1-2 curriculum that did not match their abilities, particularly in S2, would be able to move on to Access courses in S2, with the possibility of taking Intermediate 1 courses before they left school.
More academic pupils could sit Intermediate 2 exams in S3 if they wished.
To date, only maths has been offered a year early and there appear to be no signs of a wholesale acceleration.
Mr Wilson said: "In the long term, we want to make sure that kids are on appropriate courses. They will not all be doing Intermediate 1 at the end of S3, or Intermediate 2 at the end of S4. Some will be doing Intermediate 2s at the end of S3, but that is not part of the policy.
"The focus is not on age and stage, but rather on teachers assessing these kids and saying this is the appropriate course for them."
He believed the present structure lacked flexibility, did not offer enough time and depth, did not offer real progression in skills or build up young people's confidence sufficiently, and did not give young people access to appropriate courses early enough.
However, Mr Wilson believes the key element of the new structure is that it will offer more choice of subjects and the chance to study them in greater depth in S2. This, he suggests, is in line with what will emerge from the review of the curriculum.