The opportunity for two different bets to both pay out. This is often achieved by taking advantage of line movements. For example, if a player backed the 49ers to win -7 on a Tuesday but then their opponents, the Rams, drifted to +10.5 against the spread by Sunday, a bettor could back the underdog at this line, creating a “middle” if the Niners won by 8, 9 or 10 points where both bets won
