The 1972 NFL season was the 53rd regular season of the National Football League. The Miami Dolphins became the first (and to date the only) NFL team to finish a championship season undefeated and untied when they beat the Washington Redskins in Super Bowl VII. The Dolphins not only led the NFL in points scored, while their defense led the league in fewest points allowed, the roster also featured two running backs who gained 1,000 rushing yards in the same season. Colts and Rams exchange owners On July 13, Robert Irsay and Willard Keland bought the Los Angeles Rams from the estate of Dan Reeves and transferred ownership to Carroll Rosenbloom, in exchange for ownership of the Baltimore Colts. Draft The 1972 NFL Draft was held from February 1 to 2, 1972 at New York City’s Essex House. With the first pick, the Buffalo Bills selected defensive end Walt Patulski from the University of Notre Dame. New officials Referee Jack Vest, the referee for Super Bowl II, the 1969 AFL championship game and 1971 AFC championship game, was killed in a June motorcycle accident. Chuck Heberling was promoted from line judge to fill the vacancy and kept Vest's crew intact. Heberling's line judge vacancy was filled by Red Cashion, who was promoted to referee in 1976 and worked in the league through 1996, earning assignment to Super Bowl XX and Super Bowl XXX. Major rule changes The inbounds lines or hashmarks were moved closer to the center of the field, to from the sidelines. Since the season, they had been from the sideline [ apart]. The hashmarks are now apart (the same width as the goalposts), cutting down on severe angles for short field goal attempts, and nearly eliminating the short-side fields for the offense. With the hashmarks now the same width as the goalposts, a team punting from inside its 15-yard line could snap the ball from a spot even with the marked field numbers instead of the hashmarks to avoid the punt hitting the goalpost. Field number markings were standardized across the league, both in size and position. Prior to 1972, the Oakland Raiders' field numbers were inside a silver shield, and the Denver Broncos and San Diego Chargers used diamonds to mark numbers. The fields for the Houston Oilers and New Orleans Saints had field numbers closer to the sidelines than most stadiums, since they were marked