From 1950 through 1960, the Indianapolis 500 counted toward which championship?

From 1950 through 1960, the Indianapolis 500 counted toward the World Drivers' Championship.

The race became a points-paying round of the new FIA World Championship of Drivers in 1950. Indianapolis was included because the United States did not yet have a Grand Prix, and Speedway executive Theodore E. “Pop” Meyers successfully lobbied for the 500 to represent the country.

The arrangement had an important wrinkle: Indianapolis cars did not necessarily follow Formula One specifications, and the race also awarded points toward the separate AAA or USAC national championships. The FIA awarded driver points, but no Constructors' Championship points, for the 500.

The 1960 race was the final Indianapolis 500 to count toward the World Drivers' Championship. The event was often poorly attended by European Formula One regulars, partly because its date conflicted with other major races. The championship was later commonly known as the Formula One World Championship.