The modern-day sports betting menu contains a staggering number of options for wagering. Traditional point spread, total, and money line bets are now complemented with "prop" bets, in-game wagering, futures, a slew of derivative markets, and same-game parlays (which deserve a post of their own due to their one-sided nature). One of the more tantalizing types of bets offered by sportsbooks is the “teaser", a wager that allows you to adjust the point spread or total in your favor while lowering the payout and requiring you to combine multiple bets.
Teasers are interesting from a statistical point of view. In conventional betting, the bettor's task is to forecast whether the sportsbook's proposed number (e.g. a point spread or total) exceeds the median outcome. For example, in the matchup between the Baltimore Ravens and Philadelphia Eagles, the sportsbooks have pegged the median outcome to be the Ravens winning by 2.5 points. This is indicated as "Ravens -2.5". Hypothetically, if you believe that the median outcome is actually Ravens by 4 points, then you would be wise to bet the Ravens at -2.5. Now with teasers, the median outcome becomes somewhat less relevant. Instead, the bettor's challenge is to identify whether a team will keep the margin of victory within a more liberal range. As explained below, this has a tendency to keep your bet "alive" longer than conventional point spread or total bets. The question, however, is whether teasers offer positive expected value, and if so, under what conditions.
What is a teaser?
A teaser combines a parlay (a bet on more than one outcome in which all outcomes must occur to win the bet) with point spreads that have been adjusted in the bettor's favor. Each of the outcomes comprising the teaser is referred to as a "leg", and teasers may have 2, 3, or 4 legs.
To illustrate a conventional, two-leg, 6 point teaser, let's assume that you are interested in making a wager on the following two matches in the upcoming Week 13 NFL slate:
Buffalo Bills -7 versus San Francisco 49ers (conventionally, a wager on Buffalo wins if and only if the Bills beat the 49ers by more than 7 points, and nets a profit of 91 cents on a dollar wager).
Atlanta Falcons +1.5 versus Los Angeles Chargers (a conventional spread bet on Atlanta wins as long as the Chargers do not beat the Chargers by 2 or more points).
One of your options is to place two separate wagers. Your Bills -7 bet wins as long as the Bills win the contest by more than 7 points (if they win by exactly 7, you receive your money back, but no profit). As long as the Falcons do not lose by 2 or more points, your Falcons bet is a winner. For both of these bets, the payout is designated as -110 in the American odds system. This means that you must bet $1.10 in order to net a profit of $1.00. In other words, the wagers pay 91 cents on a dollar bet. In order to break even against the sportsbook in the long run, such bets must win at a clip of 52.4%, a benchmark that is deceivingly difficult to attain.
A teaser bet on the Bills and Falcons involves wagering that both of these teams will win against the spread, but after receiving a 6-point advantage:
Buffalo Bills from -7 to -1
Atlanta Falcons from +1.5 to +7.5
In betting parlance, the teaser "hits" if Buffalo wins by more than one point and the Falcons do not lose by more than 7 points. The payout on a winning bet is -120, slightly lower than the typical -110 that one receives on straight bets. Let's work out the breakeven percentage of a teaser -- the rate at which you need to win these types of bets in order to avoid a negative expected value.
EV = p(win) x 100/120 + p(lose) x (-1)
EV = p(win) x 100/120 - ( 1 - p(win) )
EV = p(win) x (1+100/120) - 1
Setting EV to 0, we have:
p(win) = 1/(1+100/120) ~ 0.5454
This means that the breakeven percentage of a teaser bet is 54.45%. Because both legs have to win for the teaser to pay out, the breakeven percentage for each of the games is the square root of this probability:
0.5445^(1/2) = 0.7385
Your teaser has a positive expected value if the likelihood of Buffalo winning the game by more than 1 point, as well as the likelihood of Atlanta not losing by more than a touchdown, are greater than 73.85%.
Due to the football's scoring system (i.e., 3 points for a field goal, 6 for a touchdown, and 1 for the extra point), many games are decided by 3, 6, or 7 points. Moreover, it is far less common for a team to win a contest by a single point. According to the conventional wisdom, this means that our Buffalo bet has added value, as betting that the Bills will win by more than 1 point is virtually equivalent to wagering on them to win the contest outright. Equally importantly, our bet on the Falcons now wins even if they lose by 3, 6, or 7 points. As these are the most statistically probable margins by which the Chargers could win, we have exploited the context-independence of the teaser bet to increase the likelihood that the game's outcome falls into the subset of outcomes at which our teaser pays.
Why is it called a "teaser"?
Without having researched the origin of the term, I can only speculate based on my own experience with placing teaser bets: because of the 6 point head start that you receive on each leg, your bets remain (on average) "winnable" for a noticeably longer portion of each match. The team against which you bet will generally require more time in order to accumulate enough points for the sportsbook to cash in on your carefully researched teaser. This is particularly true when teasing substantial underdogs. For example, imagine that you tease the Raiders up from +13 to +19 against the reigning champion Kansas City Chiefs -- even if the probability of the Chiefs winning by more than 19 points exceeds 26% (1-0.74), it is unlikely that they will reach this margin of victory in the first half. As a result, you remain hopeful for a larger portion of the game compared to a conventional Raiders +13 wager. This comes at the cost of having to wager on a second teaser leg, and the slightly lower payout (-120 versus -110).
Conventional Wisdom
The conventional wisdom on teasers is the following:
Thou shalt only tease a point spread that, when adjusted, crosses 3, 6, and 7 points.
The teaser commandment essentially limits you to one of two scenarios: "teasing up" an underdog that is receiving 1.5, 2 or 2.5 points, or "teasing down" favorites of 7.5, 8, and 8.5 points. In making this argument, 6 point teasers have been assumed. If electing to bet 7 point teasers, which carry a reduced payout of -140, the commandment would be revised to: teasing up underdogs of 1, 1.5, 2, and 2.5 points, or teasing down favorites of 7.5, 8, 8.5, 9, and 9.5 points. I will not cover teasers of 10 and 13 (!) points here, although the latter raises some interesting scenarios in games whose point total is expected to be low.
I have conducted a statistical analysis of teaser bets in NFL pregame spread betting using data from the last 6 years. The primary objective of the analysis was to test the prevailing wisdom that only certain teaser bets—those crossing key numbers of 3, 6, and 7 points—are profitable. This findings are summarized below, and are accompanied by an iPython notebook for those readers that are comfortable reading Python code. Let’s dive into the findings and see where the data supports conventional logic, and where it challenges it.
How the analysis was conducted
The analysis utilized NFL game data from 2019 to 2024, sourced through the nfl_data_py library. After cleaning the dataset to remove games with missing spreads or final scores, as well as pushes and pick’em games (spreads of zero), games were categorized into spread bins:
{1, 1.5, 2, 2.5}
{3, 3.5}
{4, 4.5, 5, 5.5, 6, 6.5}
{7, 7.5, 8, 8.5}
{9, 9.5, 10, and above}
These subsets were chosen in an effort to equalize the number of matches falling into each category.
To analyze the profitability of teasers, the pre-game spreads were adjusted by 6 points in both possible directions: in favor of the home and away team. For example, a home team favored by 7.5 points was adjusted to -1.5 points, while an away underdog receiving 1.5 points was adjusted to +7.5 points. These adjusted spreads were then assessed to determine whether the teased team covered the adjusted spread. The analysis focused on identifying profitable scenarios by computing win rates and comparing them across different spread bins and contexts (i.e., home vs. away teams).
Findings
The findings are summarized in the two figures below: the top panel contains the analysis of all games in which the home team was favored, while the bottom panel covers matches with away favorites. The value of each cell indicates the win rate of a teaser leg (i.e., how often the bet indicated at the bottom of the left or right columns wins against the teaser-adjusted spread). Remember that the breakeven percentage is 73.85%, meaning that any number exceeding 74% carries a positive expectation.
1. Teasing Underdogs Up from 1-2.5 Points
Consistent with conventional wisdom, this strategy is profitable. Teasing up a small home underdog hits at a rate of 75%, while small away underdogs cover the adjusted spread at 77%. Indeed, crossing the key numbers of 3, 6 and 7 gives significant value, making these bets a sound choice.
2. Teasing Favorites Down from 7-8.5 Points
Although somewhat inline with the conventional wisdom, the analysis reveals a key caveat: this strategy is only profitable when the favorite is the away team. Teasing down away favorites of 7-8.5 points hits at 75%. On the other hand, home favorites teased down in this range only win 69% of the time. This may suggest that the public overvalues the home field advantage, resulting in sportsbooks deliberately shading the pregame spreads (i.e., assigning larger handicaps to home favorites than the data suggests).
3. The Surprising Value of Away Underdogs in the 4-6.5 Range
The most surprising finding is the profitability of teasing up away underdogs up from 4-6.5 points. The win rate of this subset of matches is 77%, well above the breakeven percentage. Note that teasing up underdogs in this range yields point spreads that cross the +10 number, perhaps suggesting that it should be included on the Stone Tablet.
Implications for Bettors
The astute reader may be thinking: "but your analysis has just assumed blindly betting all of these teaser legs!". And you would be correct. Nevertheless, to produce an unbiased analysis of teaser profitability that makes minimal assumptions about the nature of your particular betting strategy, a blanket approach such as the one that was employed here makes sense. Moreover, the findings are not conditional on any expert knowledge or sophisticated mathematical modeling.
Moreover, fans of the teaser should be overjoyed at the fact that, over the last five years, blindly teasing all small underdogs up from the 1-2.5 point range (as well as away dogs of 4-6.5), and blindly teasing all 7-8.5 away favorites down, provides a positive expected value! Please note that this is not an invitation to mortgage your toddler's Harvard tuition on all combinations of 1-2.5 point away underdogs for the rest of the season: demonstrating statistical significance in the small-sample size NFL is challenging, and betting trends change as rapidly as Super Bowl halftime performers.
Nevertheless, the analysis does suggest that any betting angle or market inefficiency that coincides with these subsets of matches provides exceptional value. Stated differently, when debating between two candidate wagers, one should opt to bet on the one that falls into these preferred subsets, as it mitigates your risk.
I hope you've enjoyed this post as much as I enjoyed performing the analysis. And if you are wondering about Week 13, it would be Falcons, Buccaneers, and yes, the Pontiff's own New Orleans Saints.
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