line movement and live lines

I know many books and articles on sportsbetting state that when the lines moves, they move due to the books attempting lessen overloaded bets on one side or to entice betting on the other side in order to guarantee a profit on the vig. For example, say if Green Bay was playing Tampa Bay, and an early line in the week was Green Bay -6, then later in the week the line was Green Bay -8, most books and articles that I've read would argue that the movement is due to more money being bet on Green Bay. However, I was wondering if the Wizard or anyone else knows if this reason is entirely true?

The reason why I pose this question is that all the vegas and online sportsbooks are interfaced to each other where if one book moves a line, everyone will follow within minutes or in many cases instantly (depending on what book the movement stems from;you wil see this if you use an live lines service like Don Best, in which I will post a separate question reguarding the subject of live line services later), which makes me wonder why books will follow other books' line movement if they don't have an overloaded side on their books? This also makes me wonder if there are insiders or "sharps" that the books use as indicators of moving the line rather than just pure money? It also seems that many times when lines move significantly, it is not discovered until kickoff, tipoff, etc., that things like certain key players are not playing. Thus, this makes me also wonder if books track the bets of "insiders" or "sharps", and move the line accordingly or if the books have inside information themselves and move the line reguardless of how much money they have booked on each side of a game. I've also heard that in the past, the LVSC would come up with the the opening line, then they would open it up to only the sharps in order to give them time to adjust the line before opening it up to the public, but I don't know if it's true.

Sorry for the long thread, but I was just wondering if anyone can provide further insight on this?

Recent article on Sports Books and Technology mentions lines no longer originate at the Stardust but instead now originate in the Caribbean.

Article also shows betting breakdown by type of sport and that visiting a sports book and interacting with a ticket writer has become about as common as visiting a bank building and interacting with a live teller.

Article: Link to LVRJ article.

Technology brings next phase for sports books ...by Chris Sieroty
LAS VEGAS REVIEW-JOURNAL
Posted: Aug. 28, 2011 | 2:00 a.m.

I think that Frank Rosenthal was right when he said on his website that modern sportsbooks run scared. "Action Balance" is not 100% needed to run a good book as long as any one game does not get too far out of balance. In "Confessions of an Ivy League Bookie" the author states that the wire room supervisor could lay off action on almost any game. But in most cases they didn't. Why? A few reasons. First, the genreal public is either usually wrong or regresses 10 a 50/50 average. Second, say you have 4 games all out of balance the same amount. What is the chance of all 4 going against you? What is the chance of all 4 going against you if you subscribe to the notion that the public usually guesses wrong?

I believe it is correct to say why would Harrah's move from Steelers -3.5 to Steelers -4 just because Steve Wynn moves them?

This is just one more reason I say the NGCB should limit casino ownership to 2 Super-Casinos and 4 locals casinos per owner.

Sportsbooks are like commodity markets. They all sell the same thing, so, if someone is hanging a stale line, they're going to get clobbered.

If the spot price of gold is $1800 an oz, and a trader offered to buy it at $1600 and sell it at $1700 an oz, he's going to get crushed. No one will sell to him, but they will buy all they could from him. Even people who don't want to hold gold will buy from him to sell it to others are the "fair market" price of $1800. In fact, even if this guy has deep pockets, he's going to get crushed in a matter of minutes by deep pocket traders (hedge funds etc), who see that his price is "wrong".

The same thing happens with sportsbooks that hang the wrong line - they will get crushed. If they hang a line at -2 that is currently -3.5 everywhere else, they will get destroyed. The sharps than know the line is wrong wil hammer them, and so will the arbitrageurs, who get a chance to freeroll of this book. Yes, the book may get lucky, and win that specific game if the favorite doesn't cover, but, if they make this mistake consistantly, they will quickly run out of cash.

The general public rarely determines the line. It is determined by a combination of the "sharp" online books ability to handicap an original line and to adjust lines based on new information -including the action they get from their sharp customers. Because this is difficult to do, most books follow the linesetters via Don Best, etc.

If you were a bookie and a high volume customer of yours consistantly beat you, sooner or latter you would have to either cut him off or cut his limits. While cutting his limits still allows you to lose to him it also is a way for you to pay for his service of identifying bad lines. Sportsbooks have to make the same choices about their "sharp" customers.