The RIB: The Atlantis Grail #1: Qualify by Vera Nazarian

Earth is in danger! A giant meteor is going to crash into our planet, destroying all life. Luckily, the space-faring Atlantean civilisation is here to help. They used to be an ancient civilisation on Earth, thousands of years ago, before they developed spaceships and left to settle another planet. How are they going to help? Well, the Atlanteans can take immigrants from Earth back to their new planet. Except they have limited room, and only want teenagers between the ages of eleven and twenty. And only the best. So to figure out who will live on Atlantis, and who will die on Earth when the meteor strikes, the government of Earth and the Atlanteans agree to hold a tournament, where the teenagers will fight to survive! (Why don't the Atlanteans just move the asteroid? They have spaceships, after all. This is addressed in later books, but now we'll get on to the exciting bit.) I have a fondness for tournament stories. The Hunger Games, Battle Royale, or even movies like Cube and the Saw…