The free substitution rule (any or all of the players may be replaced by substitutes after any play) was re-adopted for one year. The rule was previously adopted in 1943 in response to the depleted rosters during World War II, but repealed in 1946.
In the Eastern Division, Philadelphia and Pittsburgh both had records of 4–1–0 when they met in Week Six. The Eagles won 38–7, and kept the lead for the remainder of the season. In the Western Division, the Rams got off to a 6–0–0 start while the Bears were 3–3–0 at midseason. Though the Bears won all of their remaining games, they never caught up to the Rams, who finished at 8–2–2.