You could write about the Taiping Rebellion. Basically what happened was a Chinese dude name Hong Xiuquan decided that he was Jesus's young brother, started his own religion and tried to take over China to create the Taiping Heavenly Kingdom.
In ancient times, it is said that trolls attracted people into their world, into the mountains or into the underworld and people who disappeared for a while, could come home with memory loss and confusion.
Your thesis could be (since this is about sports) “This sport is important because ______________.(whatever sport your writing about) and also because ________.