who had become a Canadian citizen at any time before signing with the league for the first time could qualify as a nonimport player. For individuals who played both American and Canadian football professionally, their career statistic totals are considered to be their combined totals from their careers in both the CFL and NFL. Warren Moon, for example, was the all-time professional football leader in passing yards after an illustrious career in both leagues. He was surpassed in 2006 by Damon Allen, who in turn was surpassed by Anthony Calvillo in 2011, both of whose careers were exclusively in the CFL. Differences Several important specific differences exist between the Canadian and American versions of the game of football: Playing area The official playing field in Canadian football is larger than the American, and similar to American fields prior to 1912. The Canadian field of play is , compared to in American football. Since 1986, Canadian end zones are deep while the American end zones are deep. Canadian end zones were previously 25 yards, with Vancouver's BC Place the first to use the 20-yard-long end zone in 1983, and since 2016, the home of the CFL's Toronto Argonauts, BMO Field, uses an 18-yard-long end zone. Including the end zones, the American field is about 34% smaller than the Canadian field ( for the Canadian field vs for the American field), but the Canadian field occasionally will have its end zone truncated at the corners so that the field fits in the infield of a running track. Once a fairly common practice, the only example today in the CFL is the Percival Molson Memorial Stadium, home of the Montreal Alouettes. The goalposts for kicking are placed at the goal line in Canadian football, but at the end line in the American game since 1974. In Canadian rules, the distance between the sideline and hash marks is ; in 2022, the CFL narrowed the hash mark spacing to . In American amateur rules, at the high school level, the distance is , virtually sectioning the field into three equal columns. The hash marks are closer together at the American college level, where they are from the sideline, and in the NFL, where they are from the sideline and the distance between them is the same as that between the goalposts. Because of the larger field, many American football venues are generally unfit for