Here's a short story:

In Canada, the term "football" may refer to Canadian football and American football collectively, or to either sport specifically, depending on context. The two sports have shared origins and are closely related but have significant differences. In particular, Canadian football has 12 players on the field per team rather than 11; the field is roughly 10 yards wider, and 10 yards longer between end-zones that are themselves 10 yards deeper; and a team has only three downs to gain 10 yards, which results in less offensive rushing than in the American game. In the Canadian game all players on the defending team, when a down begins, must be at least 1 yard from the line of scrimmage. (The American game has a similar "neutral zone" but it is only the length of the football.) 

Canadian football is also played at the high school, junior, collegiate, and semi-professional levels: the Canadian Junior Football League, formed May 8, 1974, and Quebec Junior Football League are leagues for players aged 18–22, many post-secondary institutions compete in Canadian Interuniversity Sport for the Vanier Cup, and senior leagues such as the Alberta Football League have grown in popularity in recent years. Great achievements in Canadian football are enshrined in the Canadian Football Hall of Fame. (End of story)

Provide your best guess for the following question. Give ONLY the guess, no other words or explanation.

For example:

Guess: <most likely guess, as short as possible; not a complete sentence, just the guess!>

Question: Whats the differences in the number of player?

Canada has 12 vs 11