Article snapshot taken from Wikipedia with creative commons attribution-sharealike license.
Give it a read and then ask your questions in the chat.
We can research this topic together.
Big's Backyard Ultra is the original backyard ultra, invented by Gary "Lazarus Lake" Cantrell of Bell Buckle, Tennessee. Participants run a 4.167-mile loop every hour, and are eliminated if they fail to complete a loop in an hour. The path of the loop is on trails during the day and along a road after dark. The distance of each loop is equal to 100 divided by 24, so that a competitor runs 100 miles for a full day of competition. There is no predefined finish. The winner is the competitor who completes a loop that no other competitors complete. If no competitor outlasts every other competitor, there is no winner.
When Steene dropped out to catch his flight back to Sweden, Ebel chose to drop out as well.
In 2020, the COVID-19 pandemic precluded international competitors from travelling to Tennessee, so the race was replaced by satellite events in various countries. The world title winner was Karel Sabbe in Belgium, with 76 laps.