Instead of betting on an individual game, bettors are also able to bet on the results of an entire season.  You can place a wager on the total number of games a particular team will win during the course of the season - a bet known as total season wins.  You can also bet on which team will win the championship of their division, conference or league.  Most sportsbooks will post a list of all the teams in the league and then give odds next to each, indicating the payout if you place a bet on that team and they win the championship.  These are all known as futures bets.

There are several dynamics involved in futures betting that sports bettors should be aware of.  The first is called the time value of money.  Once you place a futures bet with a sportsbook, that money is no longer available to the bettor until the wager is graded.  If you place a bet on the Superbowl champion of the NFL in August, you wager will not be graded until February.  The money from that wager is locked down until then.  Additionally, through inflation, that money will be worth a bit less in February than it was in August.  Bettors should account for this currency devaluation when figuring their edge on a futures bet.

Next, we need to look at the potential for the increasing (or decreasing) value of a futures bet throughout the season.  For example, say that prior to the 2007 NCAA football season I had placed a futures bet on The Ohio State University to win the BCS Championship.  OSU was supposed to have a rebuilding year, so I was able to get the bet at +4000, or 40/1.  I put $10 on my favorite team, the Buckeyes. 

Throughout the season the Buckeyes performed well, losing only one game.  Then, on the last weekend of the season, the top two teams lose, putting OSU in the BCS championship game.  They were slight underdogs in the championship, going off at +150 or so.  This gives them a roughly 40% shot at winning.  My futures bet, if OSU wins, is worth $400.  Before the game starts, however, it is no longer worth the $10 I paid for it.  It is worth 40% of $400, or about $160. Immediately after the game, which OSU lost, the wager was worth $0.

In this scenario my futures bet increased in value as the season progressed, even before the bet was final.  Bettors can sometimes take advantage of the changing value of the futures bet to lock in value before the wager itself is graded.  In this scenario I would have been able to place a bet on OSU's opponent in the BCS championship (LSU) and locked in a sure profit regardless of the outcome of the actual futures bet.

The Sportsbook's Advantage

If you convert all of the wagering odds into probabilities and then add them up, you will see that the total comes in over 100%.  The extra represents the overround that the book has on this bet.  The overround is a measure of the book's profits on the futures bet.  Typical overround is 108% - 110%, representing a sizable profit margin for the sportsbook on futures betting.

Also, if you took all of the total season wins for the individual teams and added them up, you would find that there are more games predicted as winners than would be possible in a league that must have as many winners as losers.  This would suggest that the bettor with the edge would be betting the "under" on most total season wins bets.  Despite this, the books continue to offer inflated season win totals, secure in the knowledge that most bettors will bet on their favorite team no matter the circumstance.