If you’re not sure who is going to win a match, but you have a feeling which side is going to score first, you can bet on the first goal.
Some betting sites in the USA even allow you (at excellent odds) to forecast which player will score the first goal. Check NJ betting apps such as William Hill and bet365 NJ for NFL, AFL betting markets on the first goal.
So in an example of Manchester City playing Manchester United, if you think Manchester United will score the first goal, you can place a wager on that (and likely get good odds). If United scores first, you win the bet. If City scores first, or if no goals are scored in the match, you lose the bet.