The 45th Hunger Games took place 29 years prior to the start of The Hunger Games series. These Games were won by Chaff, the male tribute from District 11, who lost his arm from the elbow down during the Games. Katniss Everdeen mentions in Catching Fire that the Capitol had probably offered him some sort of mechanical replacement like Peeta Mellark's leg, but refused it
It is unknown how old Chaff was during the games, (though older then when Finnick won his games, so between late 14-18), who his mentor was, or how he won but it was traumatic enough that it majorly contributed to his alcoholism to cope in the aftermath.