What are 'betting lines'? How do they work?

Question

I decided to start doing sports gambling. To learn the mechanics of it, I put a $5 bet on the Lakers. There was the following lines -370, -7.5 and "Under 193.5" I clicked -7.5. I haven't confirmed the bet yet. What exactly do those mean? If I had picked the Spurs, it would have had the same lines except positive.

Answer 1

Here is a complete explanation as found at http://GamblingReviewsSite.com

Pointspread & Over/Under Wagers

On a pointspread wager, the team wagered must win by the pointspread. On an over/under wager, the total points of the contest by both teams, overtime included, must fall over or under the side selected.

Example:

The posted line is the L.A. Lakers -10 at Portland Trailblazers +10 and the over/under total is 189.

The odds are $1.10 to win $1.00 (-110) unless otherwise indicated.

For the player who wagers on the Lakers -10, they must win by more than 10 points for this to be a winning wager. For the player who wagers on Portland +10, they must either win the game, or lose by less than 10 points for this to be a winning wager. If the outcome falls on the number, either way, the bet is declared a "Push", and the original stake is refunded.

For the player who wagers on the total points of this contest by both teams to be "Over" 189, the combined final score of both teams must exceed 189. For the player who wagers on the total points of this contest by both teams to be "Under" 189, the combined final score of both teams must be less than 189. If the outcome falls on the number, the bet is declared a "Push", and the original stake is refunded.

Moneyline Wagers

Moneyline Wagering is simply wagering on the contest based on a given price rather than a pointspread. The team wagered on just has to win the game.

Example

A player could choose one of two wagers on the following matchup: L.A. Lakers -200 at Portland Trailblazers +180. If the Lakers win, the player laid $200.00 to win $100.00. If Portland wins, the player who bet $100.00 wins $180.00.

Answer 2

You're actually betting a 'spread'.  LA is the underdog, and is expected to LOSE by 7.5 points.  You will win your bet, provided LA loses by 7 or fewer points.

Answer 3

If you clicked -7.5, then the Lakers have to win by 8 points to win the bet.  If the pointspread was -7, that means that the Lakers still have to win by 8 to win money, but if they win by 7, it is a "push" or tie and you are returned your bet.  

On the other hand, San Antonio is +7.5, then that means that they can lose by no more than 7 to win the bet.  So even if the Spurs still lose by 6 or less, then you are a winner.  

The -370 is the moneyline bet.  This is a straight up bet, and the higher the negative number (or lower, I guess) the more money you have to place to win a bigger amount.  That means in order to win $100, you have to risk $370.  On the other hand, say the Spurs are +170, then that means you are paid out $170 for every $100 you bet on top of your original bet (so you'd be returned $270 total).  

The Over/Under is betting on what the total score will add up to.  If the total score tonight is Lakers 95 Spurs 90, then the total is 185, and UNDER.  

Payouts for Over/Under and pointspread bets are usually -110.  Which means that every $110 bet will win $100.  These figures are all relative, depending on how much you actually bet.  Hope this helps.