The Hunger Games: Catching Fire followed up on the breakout success of its predecessor by bringing Katniss Everdeen back to the Capitol to participate in yet another fight to the death with 23 other tributes. But author Suzanne Collins needed to raise the stakes, which she managed to do by returning former Tributes — including Katniss — to a new version of the games called the Quarter Quell. Each contestant from Katniss' first gladiatorial combat was as inexperienced as she was. But Catching Fire's returning contestants were hardened by years of watching their successors struggle and die, and there's no one else who fits that description better than Johanna Mason.
Source：https://www.cbr.com/hunger-games-johanna-mason-won-how/
