--Fractional odds are most commonly found in racing. A 10/1 payout should be read "$10 paid for every $1 wagered." When the bigger number is on the left, you will find that bet is normally an underdog in the race. Also note, however, that in case such as "Who will win the Super Bowl in the NFL?" you will see all the teams listed as "underdogs"… i.e. paying at least 2/1 (some up to 300/1 or more).
The general purpose of spread betting is to create an active market for both sides of a binary wager, even if the outcome of an event may appear prima facie to be biased towards one side or the other. In a sporting event a strong team may be matched up against a historically weaker team; almost every game has a favorite and an underdog. If the wager is simply "Will the favorite win?", more bets are likely to be made for the favorite, possibly to such an extent that there would be very few betters willing to take the underdog.
The punter usually receives all dividends and other corporate adjustments in the financing charge each night. For example, suppose Lloyds Bank goes ex-dividend with dividend of 23.5p. The bettor receives that amount. The exact amount received varies depending on the rules and policies of the spread betting company, and the taxes that are normally charged in the home tax country of the shares.
As you can see, understanding the -110 in sports betting is pretty basic once you realize what it represents. You can also apply this knowledge to other odds as well, such as the money line. This kind of bet is different because you are betting who will win the game straight-up, which causes the odds to be different for each game (instead of -110 for everything).
Money Line: More common in baseball and hockey, pro football moneylines are growing in popularity. There is no spread, so your team just needs to win the game, not win by a certain number of points. The negative value means a favorite (-190) and a positive one indicates an underdog (+170). Picture the number 100 sitting in between these two values. Example: if you want to pick a -190 favorite, you must risk $190 in order to win $100. To back a +170 underdog, you put up $100 and win $170 if the dog wins. In some cases, betting moneylines is actually better value and can provide a bigger profit for less risk.