What are the actual underdog win rates across major sports? The contrarian thesis depends on one claim: underdogs offer value against the spread. But does the data support it?
The short answer is yes, with caveats. Underdogs across major sports cover at rates that make them viable betting options, though the edge is small and varies by sport, spread size, and situation.
Here’s what the historical data actually shows.
NFL Underdog Win Rates
The NFL is the most heavily bet sport in the United States, and it’s where contrarian patterns are most studied. According to Pro Football Reference, thousands of games provide a robust sample for analysis.
Against the spread, NFL underdogs have historically covered at rates slightly above 50%. The exact figure varies by sample period, but most studies show underdogs covering between 50.5% and 52% over large samples.
That edge sounds tiny. It is tiny. However, at -110 odds, you need 52.4% to break even. Underdogs getting you to 51-52% means you’re losing less than the public, and in some subsets, you’re profitable.
The data becomes more interesting when filtered by spread size:
Small underdogs (1-3 points) cover at roughly break-even rates. These games are close to toss-ups, and the market prices them accurately.
Medium underdogs (3.5-7 points) show the most consistent contrarian value. Public money tends to overvalue favorites in this range, pushing lines past fair value. This aligns with the core principle of fading the public.
Large underdogs (7.5+ points) are more volatile. They cover at solid rates against the spread but require stomach for variance. Blowouts happen, but so do backdoor covers.
Home underdogs are a particularly interesting subset. Teams getting points in their own stadium historically cover at rates above 53%. The combination of home-field advantage and public bias toward road favorites creates consistent value. For more on this angle, see our home underdog statistics breakdown.
NBA Underdog Win Rates
The NBA presents a different picture.
Basketball’s higher scoring and larger sample of games per season makes the market more efficient. Point spreads in the NBA are generally accurate, and underdog edges are smaller than in football.
Against the spread, NBA underdogs cover at rates very close to 50%. The contrarian edge, if it exists, is minimal across the full population of games.
However, specific situations show more promise:
Home underdogs cover at slightly elevated rates, similar to the NFL pattern.
Underdogs following a blowout loss sometimes offer value, as the market overreacts to single-game performances. This connects to the gambler’s fallacy that affects both bettors and oddsmakers.
Back-to-back situations can create underdog value when favorites are fatigued.
The NBA’s length (82 games) and the dominance of elite teams make contrarian betting harder. Consequently, the gap between the best and worst teams is larger than in the NFL, and the market knows it.
MLB Underdog Win Rates
Baseball is the underdog bettor’s best friend.
Unlike football and basketball, baseball uses moneylines rather than point spreads for most bets. This means you’re betting on who wins, not by how much. Underdogs simply need to win outright.
MLB underdogs win approximately 41-44% of their games, depending on the sample and the range of odds included. That sounds like a losing proposition, but the moneyline payouts compensate.
Here’s the key insight: the public overvalues favorites in baseball just like other sports. Money flows toward the Yankees, Dodgers, and teams with famous pitchers. As a result, the lines adjust, and underdogs offer plus-money that exceeds their true probability.
Studies of historical MLB betting data show that betting all underdogs blindly produces roughly break-even results over large samples. That’s not profitable, but it’s remarkable given that underdogs are supposed to lose more often.
Filtering for specific situations improves results:
Home underdogs with strong starting pitching show consistent value.
Underdogs against public favorites (teams with big followings and heavy betting action) cover the vig more often. Understanding public betting trends helps identify these spots.
Divisional underdogs, who know their opponents well, outperform expectations.
NHL Underdog Win Rates
Hockey shares similarities with baseball: lower scoring, moneylines, and significant randomness in single-game outcomes.
NHL underdogs win outright at rates between 38-42%, depending on the sample. Like baseball, the moneyline payouts often compensate for the lower win rate.
The NHL betting market is smaller than the NFL or NBA, which theoretically should create more inefficiencies. In practice, the sport’s randomness makes patterns harder to identify.
Home underdogs show some value historically, particularly against teams on the second night of a back-to-back. Goaltending variance also creates opportunities when public perception doesn’t match current form.
What the Data Doesn’t Tell You
Aggregate data has limitations.
Past performance doesn’t guarantee future results. The betting market adapts. Edges that existed a decade ago may be smaller now. Sportsbooks have better models, and more sharp money enters the market each year.
Sample sizes matter. A 52% cover rate sounds great, but over 100 bets, the confidence interval is wide. You could cover 52% and actually have no edge. You need thousands of bets to be confident in small edges.
Subsets get noisy. “Home underdogs of 7+ points following a loss” might have a great historical record, but the sample size is small. You might be finding patterns in noise rather than genuine inefficiencies.
The vig is always working against you. At -110, you’re paying a tax on every bet. A 51% win rate loses money. Therefore, you need to beat the break-even threshold, not just be above 50%. Good bankroll management becomes essential.
How to Use Underdog Win Rates Data
This data supports the contrarian approach but doesn’t provide a betting system.
The pattern across sports is consistent: public money flows toward favorites, pushing lines past fair value, and creating small edges on the underdog side. The edge isn’t large enough to make anyone rich, but it’s real enough to matter over large samples.
Use this information as context, not as a rule:
NFL underdogs, especially at home and in the 3-7 point range, deserve serious consideration. The underdog win rates data supports the contrarian thesis most strongly here.
NBA underdogs require more selectivity. The market is more efficient, and blanket underdog betting doesn’t work. Look for specific situational edges.
MLB underdogs, especially plus-money home dogs with good pitching, offer value often enough to warrant attention. Baseball’s randomness favors underdogs more than any other sport.
NHL underdogs are similar to baseball but with a smaller betting market. Home teams and back-to-back situations are worth monitoring.
The Realistic Edge
Across all sports, the contrarian edge is likely in the range of 1-3% above break-even in the best situations.
That’s not life-changing. It’s not a path to quick riches. But applied consistently over years, with proper emotional discipline, it’s the difference between losing slowly and breaking even or better.
The data confirms that underdogs don’t deserve the disrespect the betting public gives them. They lose more often than they win, but they cover more often than the odds imply.
That gap is where value lives.