Not the odds - the probability. Odds and probability are different representations. Under this example you are Certain is win every game. The odds are 1/0, which in math is undefined.
Odds gets thrown around a lot when the person means probability.
The probabilty of me pulling an ace out of a deck is 4/52.
Desired outcome/total outcomes
The odds are 4/48.
Desired outcomes/undesired outcomes.
As posters have noted, to attempt to be more acccurate, one would have to assign probilibities to every game. That would include team personnel, records, home field, strengths, weaknesses, more intangibles like pressure of being 13-0 or an opposing team being fired up. You can assign values to such things, but your values may be different some someone elses.
When someone says, I think Team A will catch Team B off guard, they are putting a value on something, over other things like record or personnel.
