Admittedly I don't bet sports but I think the principals are the same as for Horse racing.
I look for something that I know that the odds compiler doesn't.
For example: In a horse race it might be that a so called impressive winner was really not a improved performance as there were other clues which indicated others ran below par. If you can't establish an edge on the odds compiler there is no reason to bet in the event IMHO.
If you are not able to recognise these type of factors i don't think you can win whatever sport you are playing.
In college football, look a heads and letdowns. Also, superpower dogs and revenge. Just thinking about this subject gives me a warm fuzzy feeling in my GROIN! God I LOVE COLLEGE FOOTBALL! LT