[abev]

Long time lurker here...

Could anyone shed some light on how to create sports betting lines?

I want to make a computer program that will automatically create lines. This has been a long time idea for a "fun" app to create but just now getting around to it.

I know the programming end of it, I just need to understand the process. Is there too much criteria to have one program do it efficiently? I was thinking that the program would start with baselines then add or subtract from there? Any thoughts or resources would be a great help.

[crackerjack]

I don't know much about this but I think you'd have to have some sort of power ratings number assigned to each team. Home team gets some sort of bonus. The amount of depth you want would depend on the amount of other factors you'd be willing to program into the application. BUt for a basic line, you want power ratings.

[Justin7]

Odds making is a combination of science and art. If you want to get something in the ballpark, try this (it's not good enough to bet without adjustments).

For a given league, compute the average points scored in a game.

For each team, compute average points scored, and points allowed.

After about 8 games (NFL, NBA or whatever), the stats become meaningful. For each team, its offensive rating is (mean points scored - league average). Defense is (mean points allowed - league average).

If you want to handicap a game on a neutral field, assume each team scores the league average. For team 1's points, add its offensive rating, and 2's defensive rating to the league average. For team 2 - add 2's offense, 1's defense and the league average.

Homefield advantage? After 8 games, add up all the points scored by home teams, subtract all points scored by visitors. Divide by total number of games. In NFL, it is 2-3. In NBA, it is 3-4. To adjust for HFA, add half the HFA to home, subtract half to visitor's score. That gives you a "projected score" - you can use this for lines and totals.

If you're serious about odds making, you also need to understand injuries, variations in HFA (especially in NBA/NCAAB) and motivation.

This is just a starting point. If you want to actually bet on your model, you need a LOT more analysis.

[Arilou]

I would call power ratings the "Level 1" line program. You assign each team a number as Justin said, this can be automatic based on points scored or other pure numbers or you can handicap the teams for offense and defense and add in home field. That is good enough to tell you the rough idea of what's going on but betting on that will get you killed. A better version of level one takes into account each team's level of opposition. Either way, use Justin's method to get a line from there.

More advanced models are beyond the scope of a forum post.

[Halo]

Originally Posted by abev

Long time lurker here...

Could anyone shed some light on how to create sports betting lines?

I want to make a computer program that will automatically create lines. This has been a long time idea for a "fun" app to create but just now getting around to it.

I know the programming end of it, I just need to understand the process. Is there too much criteria to have one program do it efficiently? I was thinking that the program would start with baselines then add or subtract from there? Any thoughts or resources would be a great help.

Everyone tries to do this so have fun. When books create the spread in todays day its all done through computers. It's many databases each of which factor some sort of given statistic and each of these vary how big or little the spread on a particular game.

An example would left handed pitchers against batters on the Tigers. Your program would access the database player roster see which are L or R batters etc, etc.... This is how it is done now. You also would want to subscribe to a statistical sport reporting agency. I think there is only one so that should not be a problem. Expensive though.