Wagering on the NFL is bigger than ever, not necessarily because of the popularity of the sport but also due to underlying issues regarding the number three that has so commonly been used in linesmaking.
One in six games in professional football has fallen on this number and because more and more games are continuing to land on the number three, bookmaking issues arise surrounding the decision of how to maximize profits by moving and balancing the line.
Sportsbooks and linesmakers are cautious to tread water away from the number three because they run the risk of getting smoked by opening the door to paying out to both sides of the game if it falls on three. For instance, if they were to move away from three such as a line from 2.5 or 3.5, they run the risk of getting middled by those who have action of the game. And when a game stays at three throughout the upcoming week of a game, if it finishes at three, sportsbooks often wind up with a push and must pay back the initial wager to the customer, losing any chance to bank the vigorish (commonly known as commission for allowing bettors to place wagers).
The rapid rise of parity in the NFL is another key reason that three has become progressively more vital. It has commonly been suggested that home field advantage in the NFL is worth approximately three points to bookmakers. There are so many teams that are evenly matched, which leads to three points being made the most commonly-used spread. As well, the importance of field goals in this league and the quality of its kickers place the number three in murky water, as we have seen how many games have either been won or lost on last-second kicks.
Three points may seem like a good number, but when it moves up or down a half-point, then things get interesting. A half-point on either side of the spectrum can create a lot of issues regarding NFL games. If a favorite opens at 2.5, bettors could jump on that, not needing to factor into the equation the possibility of a field goal either way. If the line moves to 3.5, the favorite doesn't look so good; it is the underdog that looks much better.
A late-game field goal is often useless in terms of affecting the spread, and with parity comes the increased likelihood that late-game field-goal-attempts are much more common than late-game Hail Marys for a major score.