Library.

“Association football (soccer) is the most popular sport in the world.”

Available evidence strongly supports the statement. Independent sources consistently place association football first worldwide by fan base, audience reach, and geographic spread. “Most popular” can be measured in different ways, but those methodological differences do not change the overall conclusion that soccer leads globally.

“The back pass rule was introduced in association football in 1992.”

The back-pass rule was formally adopted by IFAB at its 1992 annual general meeting and became a binding Law of the Game effective July 1, 1992. Multiple independent and credible sources confirm this date. While a limited experimental trial took place at the 1991 U-17 World Cup, that was a single-tournament test—not a universal rule change. The standard understanding of "introduced" aligns squarely with 1992.