By Thursday, oddsmakers have adjusted their lines, and in an efficient market like the NFL, value bets are only available for a short time before the market catches up.

The best NFL bettors make a habit of finding value early in the week. Those looking for expected value, or +EV, consider the lines (and, by extension, probability) oddsmakers give to every game, often as early as possible, and try to figure if a bet is overvalued or undervalued. One common beginner sports bettor mistake is that they scramble through the board last minute, or look at NFL odds on Sunday morning, hoping to pick the day’s winners.

Weighing bets by expected value gives sharp bettors a fundamental advantage over most other bettors and one of the few edges they can take against a sportsbook. Why is Expected Value Important for Sports Bettors? If that bettor believes the team has a less than 50% chance to win, they would assign a negative expected value (-EV). If a bettor believes that in this game the Seahawks actually have a greater than 50% chance to win, they would assign a positive expected value (+EV). Conversely, a -190 favorite is more likely to win than a -120 favorite.īettors can convert these line numbers into an implied probability.įor example, if a book assigns a team - let’s say the Seahawks against the Patriots– a +100 line, that translates to a 50% winning probability, or a coin flip. This means a +100 underdog is more likely to win than a +240 underdog (according to the book). In this system, the line number increases as the likelihood of winning decreases, and the line number decreases as the likelihood of winning increases. sportsbooks exclusively use what are called American odds, with positive figures (such as +100, +222, etc.) assigned to the underdog and negative figures (-120, -155, etc.) given to the favorite. Oddsmakers assign their probability through betting lines, which bettors see assigned to all moneylines, point spreads, totals and any other bet type. At its simplest, expected value in sports betting is a way to measure the probability gap between a bettor’s expectations - and the sportsbook’s.

How do sports betting lines work