Premise: The NBA Finals is the championship series of the National Basketball Association (NBA). The entrants are determined by the victors of the Eastern and Western conferences, who engage in a best-of-seven game series to determine the league champion. The winners of the Finals are awarded the Larry O'Brien Championship Trophy, which replaced the Walter A. Brown Trophy in 1983.
Hypothesis: The Larry O'Brien Championship Trophy replaced the Walter A. Brown Trophy in the year after 1981.