How Lines Are Set: An Oddsmaker’s Perspective

The opening line can be a term that is thrown around pretty loosely when it comes to sports betting. You will often hear media outlets say “Vegas” opened the line this or “Vegas” has the line at that. But what does that really mean when we hear these expressions?  Is there one sportsbook in Las Vegas setting all the lines? Do all the sportsbooks get together and agree on what the line should be? Does Las Vegas even really set the line at all?

The History of Setting Opening Lines

There was a time many years ago when most of the betting lines did in fact originate from Las Vegas. Years ago, the legendary Bob Martin opened what came to be known as the Las Vegas Line during his stints at Churchill Downs and the Plaza. This line was gradually disseminated all over the country and more often than not tweaked based on anticipated regional action.

The tradition of Las Vegas helping to establish the opening lines continued years later as the Stardust Line became a respected number with the assistance of Roxy Roxborough and his company LVSC. In the mid-nineties as the internet rose to prominence and the most talented bookmakers migrated offshore, a new breed of oddsmakers emerged who set the lines from various island locales and were looking to deal higher limits than ever before to their growing customer base. This led to certain offshore sportsbooks becoming the gold standard as far as the opening line was concerned. Much of this had to do with liquidity and the fact that more money was being bet into these numbers than any other lines in the world.

The important thing to remember when discussing the opening line, is that it is just a jumping off point. It serves as a starting place for professional bettors to enter the marketplace and hammer the line out to where they believe it should be. Gambling markets are like all other markets in that they absorb information and reflect it. In the largest markets such as NFL, information is accounted for in the betting line in almost real time.

In theory, professional bettors will make a wager when they believe the current line does not accurately reflect what the information available suggests it should be. Bookmakers will react to these wagers looking to find the number that either divides the professional bettors or stops them from playing altogether. In the end, the most respected professional bettors will dictate what the betting line is, not the bookmaker. When recreational players make large wagers these wagers are often ignored due to the fact that they have no bearing on what the actual point spread should be and therefore have no reason to be reflected in the line.

How Betting Lines are Set Today

So this brings us to how the line is set today. Depending on the sport, an oddsmaker at a sportsbook will decide that he wants to open the first line. For a majority of the major American sports such as the NBA, NHL, and MLB, this still happens offshore. For college football, Circa | Sports sets the first weekly line every Sunday during football season. Once that first line is posted, if the bookmaker is taking fair limits that are enough to attract professional bettors, these lines will be wagered into somewhat aggressively depending on whether or not the bettors see value. When lines are opened, the limits are usually lower and the book that opens them is willing to be first, either for the value they see in getting this early information or for the sheer notoriety of being the sportsbook that hangs the opening line.

Once other sportsbooks see these lines being bet into and feel comfortable hanging their own lines, they will usually open lines that are relatively close to what’s already available in the market. The reason they will hesitate to open too far off of the other sportsbooks’ lines is due to the proliferation of arbitrageurs in the marketplace looking to bet both sides of a game with little to no risk. If Circa | Sports has opened Alabama -3 vs LSU, other sportsbooks would hesitate to open too far off this number knowing that they would be forcing arbitrage bettors to make a wager strictly because of any difference in the point spread.

The more time goes on and the longer these lines are bet into, the more sportsbooks around the world feel comfortable with recognizing the consensus line of the opener sportsbooks as the line they will utilize to do business. As sportsbooks around the world hang their lines, more and more bets begin to pour in, further solidifying what each book will utilize as their betting line.

When people refer to “Vegas” and what the line is they are usually referencing a consensus line from whatever they recognize as the most respected sportsbooks. The conversation regarding what are the most respected sportsbooks should always revolve around the sportsbooks that take the largest limits and don’t ban or limit players based on skill. In reality, the opening line is not as important as most people believe it is. It is the bettors who truly set the lines, not the oddsmaker.