NFL blowouts often cause sports books to take a bath. The adage "On Any Given Sunday" has become a punch line often when a NFL team has a 20-point blow out.

The NFL league is usually full of terrible teams. A few of those NFL teams in the past have been St. Louis Rams, Tampa Bay Buccaneers, Tennessee Titans, Kansas City Chiefs, Cleveland Browns, and Detroit Lions, etc. And, of course, let us not forget the Seattle Seahawks and Oakland Raiders!

The result when a so-called call NFL team plays a "bad" NFL team is a lopsided game in a sport where close contests have driven interest and, of course, betting action.

For the sports books, they must often adjust the lines. However, the sports books do not want to make the line too high; otherwise sports bettors will not place bets. Thus, individual gamblers can really find a great opportunity in betting the underdogs.

The NFL always has "bad" teams in the leaque. However, usually one or two NFL teams step up and cover during the season. Thus, it might be wise to keep your eyes on the spread.

Remember, in an effort to attract action on an otherwise lopsided game (say, Indianapolis Colts at St. Louis [the underdog in this case] on a Sunday), a sports book will offer extra points to the favorite. If not a wide enough spread, then most sports bettors would bet the Colts [well known winners at this time] and the house would get massacred.

As a rule, a betting line is fluid and will correct itself as money pours in for the favorite or underdog. An expection where the sports books would eat it would be if the sports bettors despite the favorite getting all the points to widen the spread is if the sports bettors placed bets and the underdogs beat the spread.

As a general rule the goal of a sports book is two fold. The first goal is to have enough big spreads that when a few of the underdogs inevitably cover, the house offsets the losses. The second goal is to have an equal amount of money on each side of the game to limit exposure. When the goals do not happen, the sports books generally take a bath!

Thus, the question for most sports books is how big of a spread do you dare to throw out to the bettors. Traditionally, double-digit underdogs are relatively rare and sports books do not need to worry about losing. In fact, you will find that most NFL games are decided by a touchdown or less and often a field goal or less.

In the past, the sports books have thrown up some massive numbers in college football, where especially in non-conference play the talent differential creates huge blowouts. However, that is seldom the case for a NFL team.

The highest spread that I can recall for example on a Super Bowl came in 1976, when the defending Super Bowl champion Pittsburgh Steelers were 24-point favorites against a Tampa Bay team that would go winless. In that game, Pittsburgh covered, winning 42-0.

In addition, parlay bets can sometimes be beneficial to sports bettors during the early part of the season to improve their odds. However, please keep in mind that I'm against parlay bets in general. Although, the chances that they all come through is small, which is why they are offered, a five-team parlay will generally net you at least a 20-1 payout.

In addition, geography also can play a huge roll in gambling trends – how many people in New England actually bet against the Patriots? The limited number of gamblers can make for crushing defeats (or victories) for the sports books.

The casinos, both online and land base, won’t even consider taking a NFL game off the board. Just do your homework and bet keep your eyes on the spread.