Every bettor or handicapper has his own strategy to bet. Some look at the matchups between the teams. How many points does one team score vs. how many points does the other team allow is a very popular statistic. Some other bettors look at the home-field advantage and what it means to a certain team. Some teams play very well at home (the New England Patriots were 8-0 at home in 2018 and the Los Angeles Rams were 7-1. It’s not a surprise those two teams met in the Super Bowl last season) and therefore are a good bet when they play at home.
Other teams do well on the road (New Orleans Saints and Los Angeles Chargers were both 7-1 on the road), so they were a good play when away, and some times may have even been getting points. And then, of course, there are teams that play very poorly on the road (the Miami Dolphins were 1-7 as were the Oakland Raiders) and are a good team to bet against. Other behind the scene factors could be how much traveling a team does. If a team is going on the road for a third straight week, it’s usually a good idea to bet against them.