While football in the United States is associated with crisp autumn days and cool nights, in Canada professional football begins in the summer time. While NFL training camps won't open until mid-summer by then the Canadian Football League (CFL) will be well into their regular season schedule.

The CFL is almost as old as the NFL, coming into existence in'30. The league's Grey Cup championship trophy is even older, having been awarded to the best Canadian professional football team since'09. There have been a number of NFL stars who got their start in the CFL including Doug Flutie, Randall Cunningham and Jeff Garcia.

The CFL is very high level professional football, but there are some significant differences between it and the NFL game:

The most obvious difference is the football itself–the CFL football is longer and fatter than the NFL ball. The CFL still has their goal posts on the goal line, which the NFL moved to the back of the end zone years ago. The field is 10 yards longer and 12 yards wider than the NFL field, and the CFL end zones are 20 yards deep instead of the NFL's 10 yards.

CFL teams are allowed an extra offensive player (a wide receiver), and on defense they're allowed an extra defensive back. This means that 12 players can be on the field at one time as opposed to 11 in the NFL. CFL football also differs in that teams only have three downs to gain ten yards, as opposed to four in US football. The phrase "two and out" is as commonplace in CFL football as is "three and out" in the US game.

There's also a significant difference in the way the game is scored. The first time many US fans see a CFL score update reflecting a 1-0 game they're usually left scratching their head in confusion. CFL teams are able to score a single point, known as a "single" for a kick that lands in the end zone such as a punt or missed field goal.

The rule differences don't end there–CFL teams are required to maintain a certain percentage of Canadian born players on their roster. The idea is that this will protect the unique identity of the game, as well as prevent it from becoming little more than a farm system for the NFL. Currently' of the 40 players on a CFL roster must be Canadian natives.

Many US football fans look at the rules that include more players, a wider field, and fewer downs meant to encourage more passing and expect to see a wide open high scoring style of play similar to Arena Football. That's not really how it works out–most games end up with final score totals in the 40's, but the game itself really isn't much more offensively oriented than its American counterpart. The rules may be different, but as in the NFL you need a solid rushing game and a stout defense to win games and championships.

The requirement of native born players making up 50% of a CFL roster also results in a much more even distribution of talent across the league. Certainly there are good teams and bad teams, but the end result is greater parity than is found in the NFL.

Considering the 21 non- Canadians on the team, its also important to remember that the CFL doesnt get the pick of the litter of American football talent. Certainly those who have the ability are in the NFL, or on an NFL practice or developmental squad. While some players are uniquely suited for the CFL game–former Clemson University QB Nealon Greene, for example, who couldnt make the NFL but has had a lengthy career in Canada–most of the Americans in the CFL are players whose ability just isnt up to NFL levels. Remember Vince McMahon's failed XFL experiment? That gives a good indication of the type of American player that ends up in Canada.

Despite some major differences, the NFL and CFL have more in common–they're both high level, intensely competitive professional football leagues. Once you understand the rule differences and the unique and fascinating history of the CFL, it is a very enjoyable brand of professional football to watch.

Before the Internet became ubiquitous, it wasn't easy for an American fan to keep up with the CFL. While they still don't receive coverage on ESPN, the Internet affords access to the sports media of every CFL city along with the national Canadian sports media at sites like Slam! Sports. The CFL's official site is also a great source of news, stats and information on Canadian football.

Ross Everett is a freelance sports writer and respected authority on sports betting odds comparison. He writing has appeared on a variety of sports sites including sports news and betting odds portal sites. He lives in Las Vegas with three Jack Russell Terriers and a kangaroo. He is currently working on an autobiography of former energy secretary Donald Hodell.