Is a player or team on a roll more likely to keep the streak going? Or are they due to come back to earth? Questions like these generally fall into the realm of the “Gambler’s Fallacy” and can safely be ignored.
However, the existence of these types of fallacies can lead to overreactions from bettors that can be taken advantage of. This week, we look at streaks in the NFL, keeping an eye out for those overreactions that might provide an edge.
We’ll use game data going back to 2000 to give us a reasonable sample and only look at streaks within a season – Week 1 everyone starts back at zero. Also, due to the rarity of long streaks, anything longer than six games has been grouped together.
Wins and losses
We start with just straight up wins and losses (note that a “winning” streak of minus-6 implies a six-game losing streak.) Do teams on a streak get more/less credit from oddsmakers/bettors than they deserve?
It looks like they do not. You can see that win percentage (red) increases steadily as the streak improves, as teams that go on winning streaks tend to be better than those on losing streaks. But regardless of winning streak length, a team’s ATS success stays very close to 50 percent and shows no discernible pattern.
Against the spread
Forget wins and losses, those aren’t going to move the needle for sports bettors as the action is mostly on the spread/total. Let’s first look at ATS results.
This time we see a couple interesting trends: First, it seems that teams on longer ATS winning streaks tend to be above average teams while those on longer ATS losing streaks tend to be below average. We see this from the red “Win %” line.
Secondly, and more importantly for bettors, those streaks do appear to lead to overreactions. Small streaks have little to no effect – bettors don’t adjust much to a streak of only a game or two. But as streaks get bigger, it does appear that there is an overreaction (we’ve labelled the particularly interesting points). This seems to hold in both directions, teams on winning streaks ATS underperform and those on losing streaks ATS overperform.
Over/Under
Finally, the NFL betting totals.
Interestingly, we see no clear result here. We see some very weak evidence for a couple different possible trends, but ultimately not enough to lead anywhere.
Week 12 Games
Oakland Raiders at Baltimore Ravens (-10.5)
Lamar Jackson looks like he will make his second career start and gets a great matchup against an anemic Raiders defense. The Ravens are 0-4 ATS since their Week 6 demolition of the Titans, while Oakland comes off a rare straight up win last week against the Cardinals.
New England Patriots at New York Jets (+9.5)
This is one of those lines that doesn’t feel right as the Patriots look to bounce back from their Week 11 loss to Tennessee. However, the Jets are tied with the Ravens for the longest current ATS losing streak at four games and have kept it within a touchdown in eight of their last 10 meetings with the Patriots.
