King was an inveterate better on horses. The charges were eventually dropped, but he spent several years scraping a living as a freelance writer and doing public relations work for a race track. In 1972, nearly destitute, he put his last few dollars on a horse at 70-1 and won $11,000.
To make $11 k at 70 to 1 you’ve got to bet about $160. Which, back then, was a week’s wages or so. Inveterate is one way to describe that.