By Ted Sevransky

  Lines open where they do for a reason, not by chance. Sportsbooks are designed to make a profit, not to provide a service. The reason so many new offshore books have opened over the past few years (several hundred, at least) is because they are making money for their owners. More people lose at sportsbetting than win; that is why offshores offer sign-up bonuses and other promotions to entice new clients.

  Much of the research that bookmakers use to formulate an opening line comes from a single company - Las Vegas Sports Consultants, Roxy Roxborough's former outfit (he's retired now). What LVSC does is analyze all the factors that go into a particular game. They begin with power ratings, a computerized assessment of both teams' relative talent. They factor in home field advantage and possible weather conditions. LVSC then considers the actual matchups between positions - how do the defensive backs match up against the wide receivers or the offensive line vs. the defensive line. Next they will examine the situational factors - how the teams will respond coming off various types of wins or losses, look-ahead situations or revenge games, or any other motivational (i.e. not number-crunching) factors. Lastly, they access how the bettors have responded to the teams in previous games - which side is likely to take money, and how much of a differential do they expect. In short, they handicap the games as well or better than most mortals can -- just to come up with this opening number.

  Each book then takes LVSC's analysis and opening numbers and adjusts it to their particular clientele. Some books cater mostly to large "wiseguy" players. Others take most of their money in $20 or $50 chunks from the general public. Still others take money from bookies laying off unequal action around the country or from particular regions. And many take bets from all of the above. This is why there is some variation (rarely more than a point) between the virgin numbers from different sportsbooks.

  In all sports EXCEPT the NFL, virgin lines are set to beat the wiseguys, not the public. It takes one hundred $100 bettors to equal the influence of a single maximum limit bet. So the "square" bettor (meaning the average Joe Schmo) really doesn't have that much influence over where an opening line is set - the books have bigger fish to fry. Professional football is the public's domain. There are enough small bettors to offset the big $$ that comes in from the syndicates and wiseguys. This is because there are relatively few games AND one heck of a lot of bettors.

  Every line opens at a particular number for a reason. This fact cannot be emphasized enough!! There are no accidents and few mistakes (although mistakes occasionally do occur). Our job as handicappers is to figure out why the lines opened where they did, and what it means for that particular matchup.

  One theory I have developed for analyzing virgin lines I call the "S point off key number theory" (nice name, huh). THEORY - When the line opens at 1/2 point off of a key, the house is trying to subtly influence a position among bettors. Key numbers in football include: 1, 3, 7, 10, 14, 17, 21 etc, etc. These numbers are "key" because the scoring systems of touchdowns and field goals means that the final score will have a margin of victory by one of these scores more often than not. As a bettor, wouldn't you rather be taking 7 S points instead of 6 S , or laying 2 S instead of 3 S ? Of course you would. However, past evidence has shown rather clearly that the opposite is true. Teams that open at -7.5 cover far more often than teams that open at -6.5. Why? Because a team laying more than a touchdown is supposed to be laying more than a TD, and a team laying less than 7 is supposed to be laying less than 7. Remember: a line opens at -1 instead of pick 'em for a reason!!

  In basketball, there are no key numbers like football, since the scoring comes only in 1's, 2's or 3's. But psychologically, people are still influenced by some key numbers: 4 S vs. 5 S; 9 S vs. 10 S, 14 S vs. 15 S etc. Again, I look towards the side that appears to have the worst of it - I would rather lay 10 S than 9 S . Totals work much the same way - I look to bet under a virgin total of 189.5 and over on a total of 190.5

This theory is just that: a theory, not a certainty. I use it to absolutely eliminate some sides, and to reconsider others. If there is a side that I like to begin with, and the number comes out in my favor, it is then that much closer to being a play. An opening line point off a key number is a valuable tool in the handicappers arsenal, but it no single factor makes a particular side an automatic play.

Source: www.whocovers.com