On Rambo movies for Guardian readers

I was watching another in this genre, this time with Hillary Swank in Freedom Riders.

You may not have seen it but you know the script: naive but enthusiastic teacher takes on a job in grim inner-city gang-ridden hell-hole and wins her charges over with the power of commitment and the ability to see their true potential. Meets the usual resistance from cynical establishment. 'Based on a true story', yet almost completely unbelievable. You know the sort of thing.

Now I've discussed this before but neglected to mention an absolutely crucial ingredient to this genre: ever noticed these teachers only ever seem to have one class?