Aided by Motley's swiftness and size, the Browns won the NFL championship in 1950, their first season in the league. In October 1950, Motley set an NFL record that stood for more than 52 years when he averaged over 17 yards per rush against the Pittsburgh Steelers, with 188 yards on 11 carries. In December 2002, quarterback Michael Vick of the Atlanta Falcons rushed for 173 yards on 10 carries against the Minnesota Vikings, eclipsing Motley's average. Motley also had a 69-yard rushing and 33-yard receiving touchdowns in the game. While Motley did not factor in the Browns' championship game win against the Los Angeles Rams, he led the league in rushing with 810 yards in 1950 despite averaging fewer than 12 carries per game. He was a unanimous first-team All-Pro selection.