Ender's Game by Orson Scott Card (1991)
Ender Wiggin is an exceptional little boy. He has an IQ that would make Einstein look at his feet and at the age of six he is already an obvious leader and a tactical genius. With the right training, he has the potential of becoming the greatest military mind since Alexander the Great. That's a lot for any child to be burdened with, but Earth faces repeated invasions by a deadly race called the "buggers" and if the Earth fleet can't find Alexander the Great in a hurry to lead it, then mankind is doomed. So Ender is sent to Battleschool; an orbiting academy dedicated to turning child geniuses into military commanders. Since the tests all show that Ender is, to use a cliche so worn you can feel a penny through it, The One, his childhood is set to become a living hell as Colonel Graff, in charge of Ender's education, forces the boy to become the greatest tactical leader in history before he's old enough to shave. That is, if Ender's training doesn't get him killed first.
Ender's Game is what the Harry Potter series should have been six years before the first Potter book came out. Like Potter, Ender is a boy with an unwanted destiny; marked as special from birth and required to face danger and death at too young an age before he goes on to his final battle. He also has a schoolmaster who cares about him, yet is willing to withhold information and put him through nine kinds of hell, has a loathsome brother, and there's even a form of Quidditch. Ender's version, however, is a zero-gravity combat game that's actually interesting and forms the backbone of the story. But this is not a sports novel. The Game of the title is "game" as in war games and is treated with as much seriousness
The only real difference from Potter is that in Ender's case, the unending whimsy, bad writing, clumsy plotting, and tangled continuity are missing. Ender's Game is a coming of age story in the vein of Robert Heinlein's juveniles, but without the Heinlein standard character. Graff isn't the Old Man and Ender isn't Competent. He's a small, often very frightened boy who misses the childhood that's been taken from him, feels isolated from the other boys as his successes in the Game and against assorted bullies grow, and he comes to hate his teachers as faceless sadists intent on destroying him and the team that he leads like an army. Like all good coming of age fiction, Card doesn't treat childhood like a static state, but allows us to see the boy inside the man. At times, it's often hard to remember that Ender is between six and eleven as the story unfolds or that he's fighting other children.
Card's style is reasonably paced and he keeps the story moving along, though the subplot involving his megalomaniac elder brother seems irrelevant and half-heated. The Battleschool scenes are crisp and Card knows when to cover the war games in detail and when to let them pass in a quick sentence. Though the climax of the novel is good, it's also easily foreseen and the gap between Ender leaving Battleschool and getting to the denouement leaves a sag in the plot. Card also admits that he wrote this book to set up the Ender character for later novels, which is a pity because the ending is unsatisfactory and unconvincing from a dramatic point of view. Had he written this as a stand alone with an ending to match, Ender's Game would have been a much stronger book.
Still, I'll take Battlechool over Hogwarts any day of the week.