What Are Marbles on an F1 Track?

Marbles are the small balls of rubber that accumulate off the racing line during a Formula 1 race. As tyres wear, small pieces of rubber detach and roll off the track surface into the areas cars don’t normally drive through. These rubber pellets reduce grip dramatically — almost like driving on ball bearings. During the race, drivers on the racing line avoid the marbles, but during an overtake or when a driver goes wide, they can encounter them and suddenly lose control.

Example: He went too wide at the exit and drove straight through the marbles — you can see him fighting to keep it on track.