URGENT: Fanduel is offering a new promotion: the “NBA Win Bonus.” For select NBA games, Fanduel is giving $3 in site credit for every point your team wins by. The catch is that you need to place a $25+ moneyline bet on your team (reminder: moneyline bets win only if your team wins, regardless of score). To determine if this promotion is worthy of taking, we need to determine if we have positive expectancy. The promo is being offered for the Pacers vs. Pistons game tonight (11/8/2019), tipping off in an hour and twenty.

Since this promotion offers $3 for every point our team wins by, intuition says to bet on the favored team, the Pacers, as they are more likely to win the game. As seen in the image below, the Pacers are 7.5 point favorites against the Pistons. In other words, the result expected by the market is “Pacers win by 7.5 points.”

Pistons vs. Pacers Spread and Moneyline on Fanduel
Since the Pacers are expected to win by 7.5 points, we expect $22.5 (7.5 x $3) in profit from the NBA Win Bonus (if we bet the moneyline on the Pacers). Next, we need to calculate the vig.
The vig for a moneyline wager is the overround/(1 + overround). The overround is 4.0% (1.04 = (100/360+320/420)). Thus, the vig = 4/104 = 3.8%. For every $25 we bet on the moneyline, we lose $0.95 (0.95 = 25 * 3.8%) to the house.
However, the $22.5 in promotional value from the Win Bonus is clearly larger than the $0.95 vig, so this bet is a must do. A $25 bet on the Pacers is expected to provide $21.55 in profit ($22.5 promotional value - $0.95 vig), or an expected 86% return on capital. Anything over 0% expected return is considered positive expectancy. It’s rare to find a bet that has 86% positive expectancy.
Note that as our bet size increases, our vig increases, but our credit from the promo does not. The bet has positive expectancy until the point at which the vig is equal to the credit expected by the market ($22.5).
3.8% * x (to calculate vig) = 22.5 (expected credit); x = $592.
Thus, we have positive expectancy on all bets from $25 to $592, but our highest expectancy is at $25, so we should not get emotional and bet the minimum of $25 on the Pacers on the moneyline. This promotion only applies on Fanduel currently--we do not advise making this bet on sites without the promotion, as we would not be confident in having positive expectancy.