Vegas lines

[Dave Gray]

I created this thread, because I want to delve deeper into some ideas started in Dolphins Discussion.  I think that people tend to oversimplify Vegas oddsmaking and how it works.  I think there's a bit of art to it and it's not all science and numbers.

I can't confirm any of this, but I think that the idea that booksmakers want 50% of the money on each side to secure their chance to make money on the vig is MOSTLY CORRECT.  But not 100% of the time.  I've heard these gambling experts on the radio talk about cases where the oddmakers have a team winning by 10, but the line is only 5, so they'll move the line IN THE DIRECTION PEOPLE ARE ALREADY BETTING to encourage more money on the sucker bet.

I believe that's rare, but according to some radio "experts", that occurs.

I think that you also have bookmakers -- people behind the scenes setting the lines based on a combination of statistical modeling and public perception.

And then, from the gambling that I actually do, rather than moving the lines in terms of point swings, the websites will start all bets at (-110) and then move to (-115) when something gets popular.  I don't think people pay as much attention to that.

[fyo]

^ That kind of thing worked well back before the Internet when gambling was done locally. Punters in local markets are often biased and will (typically) bet on their home team even if the odds are worse than they "should be". It probably still happens in places that have an effective local monopoly, but anything with an online presence...

These days, if you tried that as a bookmaker, you would quickly get arbitraged - unless you could convince all the other bookies to do the same thing as you.

Arbitrage is one of the reasons why bookmakers will rarely stray far from the existing lines with their own opening line. There are a ton of bots automatically doing arbitrage, so it's pretty much impossible for lines to stay too far apart since the money will come flooding in on both sides.

As for who sets the opening line, it really used to be Vegas (and Churchill Downs before that), but today the earliest lines are virtually always offered by overseas bookies. BetOnline and Betcris are some of the earliest movers offering a line pretty much right after the Sunday afternoon games are over. Or at least they used to. Haven't placed a wager in while .

[Dave Gray]

When I gamble, I very rarely try to predict outcomes and I more try to bet on a reflection of popular opinion.  I like to bet against recency bias or overreactions to big events.  I like to bet against blind-spots in big market teams and national media stories.

I've done pretty well that way.

[Spider-Dan]

I've heard these gambling experts on the radio talk about cases where the oddmakers have a team winning by 10, but the line is only 5, so they'll move the line IN THE DIRECTION PEOPLE ARE ALREADY BETTING to encourage more money on the sucker bet.

As strange as this is to say, I don't think casinos are in the business of gambling; they leave the gambling to the customers.

What you are describing is, in effect, a bookie making a bet on the outcome of the game: they are pushing money towards what they believe will be the losing side.  That seems like a really quick way to go out of business.

[Dave Gray]

As strange as this is to say, I don't think casinos are in the business of gambling; they leave the gambling to the customers.

What you are describing is, in effect, a bookie making a bet on the outcome of the game: they are pushing money towards what they believe will be the losing side.  That seems like a really quick way to go out of business.

As I understand it, this is usually, but not always true.

According to this one oddmaker guy, sometimes the public doesn't accept the modeling, so the casinos will try to coax more money out of the sucker bet.  I wish I could remember which game that was that he was talking about.