An electronic sports book wagering system provides a bettor with an opportunity to purchase a sports book ticket sell back option when placing a bet on the outcome of an event. An option may be purchased by a bettor to be exercised at will by the bettor during a break in play or during an indicated period of the event for the bettor to potentially receive compensation to cancel the wager (e.g., at half time during a football game on which the wager was placed). The amount of compensation or refund provided to the bettor upon exercise of the option may be determined based on a current probability at the break in play or indicated period of whether the bettor will win the bet for which the wager was made. The bettor may be guaranteed a minimum refund amount of the original wager upon exercising the option.