That would work better if things were more continuous. Having gifted classes imposes several practical barriers: - Resource constraints (e.g. can only afford t

That would work better if things were more continuous. Having gifted classes imposes several practical barriers: - Resource constraints (e.g. can only afford to teach sixty students) - "catching up"; entering an existing gifted class stream after missing the first few years - You'd want to select early in the school year. Joining a gifted class in the last few weeks of the year is pointless - Kids in gifted streams want or are pressured to remain there Modifications of the current distribution outside of the source and those factors above can result in zero sum outcomes. It's rhetorically useful to wave this off but still a practical concern.