Over the past few years, daily fantasy sports interest created a flurry of interest in sports gambling. The anti-gambling stigma that existed for decades has been fading in quickly, giving way to a massive, multibillion-dollar legal sports gambling industry.  With sports gambling now legal in many states (and others working on their own legislation), millions of sports fans are looking to enter the betting market for the first time.  To get a handle on the subject, it’s important to first understand the different terminology.  

Favorites vs. Underdogs

When oddsmakers release betting lines on any game, they first decide which team should be the favorite and which should be the underdog.  The favorite is the team that the oddsmakers believe will win the game and will get a minus sign next to its odds.  The underdog, then, is the team expected to lose and gets a plus sign. If the game is a toss-up, sportsbooks will list the game as a “pick” or “pick’em.”  

The determination of a favorite and an underdog is made based on a number of criteria, too detailed to include here.  The basics are the location of the game, player injuries, performance histories, etc. 


There are two primary ways to bet on either the favorite or the underdog.  The first, in most instances, is the point spread, which is a bet on the margin of victory.  A favorite “gives” points, while an underdog “gets” points.  

For example, say the Tampa Bay Buccaneers are 8-point favorites (-8) against the Kansas City Chiefs.  If you bet on the Buccaneers, they need to win the game by nine points or more for the bet to win.  If they win by nine points or more, you “cover” the bet; however, if they win by eight points, that’s a “push,” which means you only get back the money you originally bet.  If the Bucs win by seven points or fewer (or lose the game), you lose your bet.

On the other side of that, if you bet on the Chiefs “plus the points” (+8), you need them to either win the game or lose by seven points or fewer for you to win your bet.

Spreads are available for all sports, but they are predominantly used when betting on higher-scoring sports, such as football and basketball.  


The second way to bet on the favorite or the underdog is on the moneyline, a bet on which team will win the game outright.  The favorite is given a “minus” designation, such as -100, -210 or -450.  If a favorite is -100, that means you have to risk $100 to win $100.  If the favorite wins, you get $100, but if the favorite loses, you lose that $100.  Because favorites are expected to win, there is less risk when betting on them.

Underdogs are given a “plus” designation, such as +100, +200 or +300.  If an underdog is +100, that means that a $100 wager will give you $100 (plus your original bet) if the team wins.  If it loses, you lose only the $100 that you risked.  Because underdogs are expected by oddsmakers to lose, there is more of a reward (more risk) in the bet. 

Moneylines are available for all sports and are one of the most common types of wagers.  However, they are also mostly seen in lower-scoring sports like baseball, hockey and soccer.

Over/Unders (Totals)

In addition to setting a line for the favorite and the underdog, oddsmakers will also set a total number of points they expect to be scored in a game by both teams. This is called the Over/Under (or total).  Bettors can then place their wagers on whether or not the game will go Over or Under the total score.

For example, an NFL game between the Bucs and Chiefs might have a total of 54 points.  Gamblers can either bet the Over 54 or the Under 54.  If you bet the Over and the total points scored end up being 55 or higher, you win your bet.  If the total points scored are 53 or fewer, you lose.  If the final score is 54, it’s a push and you only get back the original bet.  

Explaining the -110 Number Beside A Bet 

Oddsmakers put a “tax” on every bet, which is typically called the “juice” or “vig” (short for “vigorish”). The juice is the commission gamblers pay to the sportsbook for them to accept your wager.  

Say the Carolina Tar Heels are -6 (-110) are against the Duke Blue Devils.  This means that, if you want to bet on Carolina as a 6-point favorite, you need to risk $110 to win $100.

The juice can also be a positive number, such as Indiana Hoosiers -9 (+110).  In this case, if you bet $100 on Indiana as a 9-point favorite and it covers, you win $110.  If the bet loses, you lose only the $100 that was risked.

Rotation Numbers

Rotation numbers are what are listed to the left of a team on the board. They are also referred to as the NSS number or Vegas ID number. They are unique to the team, sport and league, and universal across most sportsbooks.  For example, you might see the number “312” listed next to the Bruins -110.  If you’re at a casino and want to bet $200 on the Bruins, tell the cashier, “$100 on 312, Bruins -110.”

Lines Move in Real Time

Much like stocks, the sports betting market is fluid.  Throughout the course of the day, bookmakers will – and often do – adjust the odds.  These changes are made based on the action the sportsbooks are taking and news pertaining to the game, such as injuries and weather.  For example, if the Chiefs open as 3-point favorites and the vast majority of bets are on them, gamblers will likely see the Chiefs’ line move from -3 to -3.5. The line could move even further, or it could be “bought back” to -3.

Shop for the Best Line

Lines can vary based on the sportsbook since different operators have different clienteles.  As a result, one sportsbook may post the Chiefs -3, while another has -3.5.  Having access to more than one sportsbook allows gamblers to shop for the best line and, therefore, the best return on investment.  Getting an extra half-point might not seem like a huge deal, but it adds up and increases your chances of winning.

Placing Bets

With legalized sports betting spreading, sports gamblers have a lot of options available to them to place their bets.  Some of the biggest states that have legalized mobile wagering include Colorado, New Jersey, Pennsylvania, Indiana, West Virginia and several others.  Because the landscape is changing and new states are being added, it becomes problematic to try and provide a completely updated list.  

In addition, some states have authorized online sportsbooks, while others only allow land-based operations.  To further complicate matters, some states have prohibited bets on in-state college athletics, while others allow sports wagers on every sporting event. 

Knowing How Much to Bet

How much to bet is not something that can be suggested, but a good rule is that gamblers should only risk what they can afford to lose.  Sports gambling should be viewed as a marathon, not a sprint.  As with virtually everything, there will be good and bad days. 

As a result, a flat-betting approach is recommended.  This means betting the same amount on every game, while risking only between 1% to 5% of the bankroll per play.  The bankroll is how much a gambler allocates to the gambling activity and responsible gamblers will strictly adhere to their bankroll limits.  As an example, if you start with a bankroll of $100, you should risk no more than $5 per game.