1920 in Canadian football 1920 in Canadian football CIRFU and IRFU adopted a four-yard Interference rule while the CRU opted for three yards of Interference. ARFU played games with 12 players per side and introduced the snap-back. The reduction in the number of players was done for monetary reasons as train rates were high after World War I. The CRU would make the same changes in 1921. The MRFU champion Winnipeg Victorias were unable to field a full team for the WCRFU finals and withdrew from competition. The MRFU wanted to substitute the second place University of Manitoba Varsity team but the SRFU refused
Comparison of Canadian football and rugby union substituted off for any reason except for minor bleeding is not allowed to return to the game (with the possible exception of front-row forwards). Rugby teams may make up to eight substitutions. There are fifteen players on the pitch at all times. Players who are verified as bleeding by an independent medical official are sent to the "blood bin," where they can receive medical treatment, and replaced until they have stopped bleeding. Ejected players in Canadian football can be replaced with a substitute, while in rugby union ejection means the team must play a man down the remainder of the