I only see from 5-10 National Merits per year at GHCHS.
Garland, TX does have a "gifted program" but they produce few NMSFs and virtually no kids do well on the AMC tests. The same can be said for the Dallas Magnets. Carrollton is fine, but in reality, they just work two grades ahead. The curriculum does not accelerate after that. Plano, TX does have a dedicated math program called "math rocks" that is showing major successes. There are also some similar programs in NYC, DC, and San Jose area.
In general, if you are after publics, you have to look at the number of NMSFs as a % of the graduating class and how many do well on the AMC tests. The presence of these two indicators means that there are a number of high IQ kids and a cadre of teachers who teach to that level. 30 NMSFs per year and a dozen kids doing well on the AMC means that there will be whole classes full of MG kids with a few PGs present. The same goes for privates.
If your kid is PG, be prepared to be disappointed along the way by schools, no matter who they say they cater to. The number one thing in Prek/K is compliant manners. A highly energetic and questioning kid will be the outlier and will be seen as a "problem" with few exceptions. They can be reading Magic Treehouse and doing logarithms, but if they cannot sit still, then they will "not be ready" for K or 1st.
You will have to supplement to keep ahead of your kids.
