I have been betting on sports for over ten years. What I have learned is that there is no "system" or easy rules for winning. If there were, everyone would follow them; make a living betting on sports and quit their day jobs.
Handicapping sports is an intelligence test. You have to be able to evaluate intangibles such as back-to-back games; injuries; let-down situations; look - aheads, and team motivation.
Making money at sports betting is NOT about betting the stronger team and laying points. If that worked, everyone would quit their day job and handicap sports.
You have to immerse yourself in the sport. Watch an NBA game every night. Record the box scores from the day before EVERY DAY. You have got to go to bed thinking about NBA games and wake up in the morning thinking about NBA games.
If you do that, you will train your mind to recognize good and bad situations. Your mind is a computer, and will process information in ways that you are not consciously aware of. When you look at the card for the day, good plays will just jump out at you. The best games I have ever bet required no handicapping. I looked at the line and I just knew that the line was wrong.
For more information on this mental process, read "Blink" by Malcom Gladwell.
Read the Forum for information, but don't tail the most popular posters. That is NOT a successful betting strategy.
Follow your own light, and play "within yourself." Don't guess.