Whenever looking at the odds for NBA Basketball, it is important to keep in mind the fact that Vegas is motivated by profit. If Vegas knows that 80% of the public will favor a certain team, you can expect the odds for that team to be shaded by 1-3 points. For example, a team that would under normal circumstances be a 3 point favorite can be set as much as a 6 point favorite. This is what they say as the public betting up the line.

There is no doubt that the astute handicappers will always profit if they are good. There are two types of handicappers: systems bettors and power ratings bettors. Both are good in their own right but both have significant disadvantages.

A systems bettor would look at a team's situational factors and make a wager one way or the other. A quite common system would include something like "going against a team on zero days rest against a rested foe with revenge". The disadvantage of such a bettor is that Vegas always keeps track of systems and fades their lines. For example, teams on zero days rest will get an extra 1.5 points to their nba odds compared with if they were rested.

A power ratings bettor makes a prediction on the final outcome of a game based on the teams involved, the home court advantage. The disadvantage to the power ratings bettor is that they do not have the ability to predict situations where a team will outperform and underperform. Will a team be looking ahead?

Vegas uses a mixture of power ratings, systems, and public perception to develop good NBA Odds. They start with a power ratings prediction on what the final outcome should be. They then use commonly used single-scope systems to adjust the line. If they are rested, they will be giving up more points. If they have a division rival or a great team coming up, they will be getting more points. Single-scope means that Vegas does not look beyond 1 or 2 systems factors together. Doing so would require too much effort. After this is done, they will analyze public betting tendencies and fade the line against the public by a point or two.

Think about all those games you lost by a half point or a full point. If you were going with the public, Vegas ate you alive. If you are a systems bettor and continued to use the same lame system that Vegas finally caught up to, Vegas ate you alive. If you are a power ratings bettor but disregarded situational factors, Vegas ate you alive.