Injuries, and their importance, are accentuated when an injury occurs to a Canadian. Knowing when these situations occur and the affect they have on the entire roster is imperative. History is history, remember that. How a team plays today is irrespective of how the team before them played or even how these same teams played previously, conditions are never identical. A football is not round and doesn't bounce true, and bounces can certainly alter the outcome of a wager.
Current Form is a much more important factor.
Trends work for some other sports such as baseball but only because these are current trends and relate to current form and are feasible due to the number of games played every day. Even then a trend would never be the sole influence behind a wager. Those who do bet CFL without much knowledge of the teams and no knowledge of handicapping will more than likely bet the favorite. These people interpret one team being the 'favorite' as the superior team but this is not always the case. Last year Toronto was often a huge favorite because the team is easily recognizable due to the city in which they play and most people know the leagues' star QB, Doug Flutie, who happened to play there.