A player prop bet in fantasy football is a bet on how well a player will perform during a game. Prop bets do not take into account players' overall body of work, but rather their performance relative to a specific statistic.
The statistic at hand varies by position, as each position has different ways of scoring for their teams. Running backs, for instance, tend to score fantasy points by running for touchdowns. A typical prop bet for a running back would be over or under 2 rushing touchdowns, meaning bettors have to decide whether the player in question will run for more or less than 2 touchdowns by the end of the game.
The same process applies to quarterbacks, with the only difference being that quarterbacks pass for touchdowns. Thus, a prop bet for a quarterback may look something like over or under 3 passing touchdowns.
Each prop bet is accompanied by a 'line' set by Las Vegas sportsbooks. Lines reveal the amount of money bettors must wager in order to receive the desired reward. Each line is accompanied by a +/- sign. A minus sign indicates that there is a high probability of a certain outcome according to Vegas projections, while a plus sign means the outcome is less likely.
For example, if the prop bet is an over/under on whether Todd Gurley (star running back for the Los Angeles Rams) will score 2 rushing touchdowns and the over line is set at -135 while the under line is set at +105, this means that Gurley is expected to rush for 3 touchdowns. Expectations are accounted for in each line. In this case, a bettor must wager 135 dollars in order to win 100 on the over, compared to 100 dollars for a payout of 105 on the under.
Prop bets are best utilized when the bettor is uncertain of the game's outcome. By placing a wager on a prop bet, the bettor is gambling on an individual player's performance rather than the team as a whole. This gives the bettor a chance to win the wager even if the team has a poor collective performance.
For example, if the Los Angeles Rams lose a game by a score of 35-21 but Todd Gurley accounts for all 21 of the Rams points by running for 3 touchdowns, bettors that took the over still win money.