You certainly have the right to disagree with me, but before you do, you should really do some investigative work. Have you ever worked in a book? If I beat you, I TAKE YOUR MONEY. I TAKE the money that you gave the books. Notice that I said that this is what happens "normally" but not always. I have been wagering before you were born. I learned from the best. The books are NOT in the business of determining which line is the best, or which team is the best. The Vegas Sports Book is part of the greater Casino strategy. The Casino General Manager expects a certain profit from each of his section managers. The Sports Book Manager will take advantage of certain situations, but he/she does NOT create these situations. People like myself and other sharps make these situations happen, by using tricks like the "bait and switch" to sucker Joe Pub into wagering on the wrong side.
Here is an example of how "the sharps" use Joe Pub. In 2009, Tim Tebow was leading Florida to a National Champion. He was injured in a game against Kentucky. Florida had a bye week before playing LSU in Baton Rouge. Florida opened up at -12 against the then undefeated LSU team. Then, some well placed rumors about Tebow's status caught fire, and the line dropped to 6. The people who started the rumors had taken LSU +12. When it becamse aparent that Tebow would play, the line eventually climbed back up to 10, but the ones in the know had already taken Florida -6 1/2. Florida wins the game 13-3, a 10 point win and a push ATS, except for the sharps who cashed in on a very nice "middle". The majority of the people who wagered lost. The casino's did quite well because there was so much action on this game, the vig was huge. That is how it is done. That is why 12% of the people who wager are winners, and 85% are losers.
Now if you are talking about "Off Shore" books, that is totally different. They can, and often do, whatever they want because there is absolutely NOTHING that people in the US can do if they get cheated, which also happens too many times. I have worked in Vegas part time for several years, shoring up their security. I know how things are done. Believe what you want, but how much money have you lost over the years? You probably will say that you have won, but everyone in here does. This is why I keep a Spreadsheet in here. Anyone can look and see exactly how I do. GL this year, no matter what you may believe. Look at it this way. Do you really think that your brain can out think a computer? Believe me, Vegas books have thought of everything that you can possible think of. A famous Italian was once asked if table games and sports were rigged. His answer was spot on. He said: "Why rig the games when we can make so much money having legitimate games".