"Apparently Kerouac, also a little nuts about horse races, created a system of fantasy horse racing using marbles. He actually describes a version of this game in Doctor Sax ..."

And with fantasy horse racing: "The ball bearing traveled faster than the marbles, some of which were intentionally nicked to indicate equine fragility and mortality. So the ball bearing became the nearly invincible horse Repulsion, 'King of the Turf,' whose legendary speed and stamina are celebrated in Kerouac’s racing sheets."