What is a Longshot in Betting?

A longshot is a bet placed on an outcome that is highly unlikely to occur. These wagers are characterized by extremely high odds and, consequently, massive potential payouts if they win. The term perfectly captures the essence of betting against the odds—you're making a "shot in the dark," backing an underdog or rare event with minimal probability of success. While longshots offer the allure of life-changing returns from a small stake, they carry extreme risk and are statistically unlikely to win.

Core Definition and Characteristics

In the world of sports betting and gambling, a longshot represents the ultimate high-risk, high-reward scenario. When you place a longshot bet, you are wagering on an outcome that the sportsbook considers highly improbable. The probability of success is minimal, which is precisely why the odds are so generous. Think of it as the inverse of betting on a favourite—where you risk a large amount to win a small amount, a longshot requires risking a small amount for the chance to win a massive sum.

By its very nature, a longshot is a high-variance bet, meaning you should expect long periods of losses punctuated by occasional, significant payouts. This volatility is a defining characteristic. While a conservative bettor might prefer steady, smaller gains through favourite betting, those who gravitate toward longshots embrace this high-variance environment for the potential of a single win to eclipse numerous losses.

How Longshots Differ from Favourites

The distinction between a longshot and a favourite is fundamental to understanding betting markets. A favourite is the selection most likely to win, reflected in short odds (e.g., 1/5, which means a £10 bet wins £2). A longshot, conversely, is the selection least likely to win, reflected in long odds (e.g., 50/1, which means a £10 bet wins £500).

This relationship is inverse: as odds lengthen (become longer), the implied probability of winning decreases. A favourite at 1/5 odds implies approximately 83% probability of winning. A longshot at 50/1 odds implies approximately 2% probability of winning. The sportsbook sets these odds based on their assessment of true probability, adjusted for their margin (the "vig" or vigorish).

The practical difference is stark: betting £10 on a 1/5 favourite and winning generates a £2 profit. Betting £10 on a 50/1 longshot and winning generates a £500 profit. However, you'll lose that £10 far more often with the longshot than with the favourite.

Where Did the Term "Longshot" Come From?

The word "longshot" has a fascinating history rooted in sporting tradition, particularly horse racing. Understanding its origins provides insight into how betting terminology evolved and why certain terms persist across different sports.

Historical Origins in Horse Racing

The term "longshot" originated in 19th-century horse racing, where it was coined to describe horses with very long odds of winning. The phrase literally referred to a "long shot"—a difficult target to hit, much like trying to shoot an arrow at a distant target. In the context of horse racing, a longshot was a horse that bettors had difficulty "hitting" (selecting as a winner) because its odds were so unfavorable.

Horse racing was one of the earliest organized betting markets in modern history, particularly in the United Kingdom and United States. As betting markets developed, clear terminology emerged to describe different categories of horses based on their odds. A horse at 50/1 odds was a much longer "shot" than a horse at 5/1 odds. The term stuck because it intuitively captured the difficulty and improbability of the bet.

The terminology became so embedded in horse racing culture that it persists today. A horse racing longshot is typically defined as any horse with odds of 15/1 or longer, though this threshold varies by market and context.

Evolution Across Sports and Betting Markets

As sports betting expanded beyond horse racing in the 20th century, the term "longshot" naturally migrated to other sports. American football, baseball, basketball, and soccer betting all adopted the terminology. Today, a longshot in any sport refers to a team or competitor with very long odds, regardless of the sport.

The term's evolution reflects broader changes in gambling culture. In the early 20th century, betting was primarily associated with horse racing and illegal underground betting rings. As legal sports betting expanded—particularly in the United States after 2018—the terminology became standardized across regulated sportsbooks. Modern online betting platforms use "longshot" consistently across all sports, making it one of the most universally recognized betting terms.

Interestingly, the digital age has refined how we identify longshots. Modern sportsbooks display odds in multiple formats (American, fractional, decimal), making it easier for bettors to instantly recognize when a selection is a longshot based on the numerical representation.

How Do You Identify a Longshot Using Odds Formats?

Identifying a longshot is straightforward once you understand how to read odds. The three primary odds formats—American, fractional, and decimal—all clearly signal when you're looking at a longshot. The key is recognizing that larger numbers indicate longer odds and therefore longer shots.

Understanding American Odds (+/-)

American odds, also called moneyline odds, use a plus (+) or minus (-) sign to indicate underdogs and favourites respectively. Longshots are always displayed with a plus sign (+), and the larger the number, the longer the shot.

For example:

• +150 indicates a moderate underdog (implied probability ~40%)
• +500 indicates a significant underdog (implied probability ~17%)
• +5000 indicates a longshot (implied probability ~2%)
• +10000 indicates an extreme longshot (implied probability ~1%)

The interpretation is straightforward: a +5000 odd means that a £100 bet would win you £5,000 if successful. The magnitude of the number directly correlates to how unlikely the sportsbook considers the outcome. American odds are commonly used in the United States and increasingly in UK online sportsbooks.

Fractional Odds (Ratio Format)

Fractional odds, the traditional British format, express odds as a ratio (e.g., 50/1, 100/1). Longshots in fractional format are identified by large numbers in the numerator relative to the denominator.

For example:

• 5/1 indicates a moderate underdog
• 20/1 indicates a significant underdog
• 50/1 indicates a longshot
• 100/1 indicates an extreme longshot

The interpretation is also straightforward: 50/1 odds mean you win £50 for every £1 you stake. If you bet £10 at 50/1, you'd win £500. Fractional odds remain the standard in UK betting shops and among traditional bettors, though they're less common in online platforms compared to decimal odds.

Decimal Odds (European Format)

Decimal odds, used primarily in Europe but increasingly in UK online betting, display the total return (stake plus winnings) for every £1 wagered. Longshots are identified by high decimal numbers.

For example:

• 2.50 indicates a moderate underdog
• 21.00 indicates a significant underdog
• 51.00 indicates a longshot
• 101.00 indicates an extreme longshot

The interpretation requires a mental adjustment: a 51.00 decimal odd means your £1 stake returns £51 total (£50 profit plus your £1 stake back). If you bet £10 at 51.00 decimal, you'd receive £510 back (£500 profit plus your £10 stake). Decimal odds are favored in online betting because they make calculating potential returns straightforward multiplication.

Quick Identification Rule: Anytime you see odds that promise a return of 20, 50, or 100 times your initial stake, you've found a longshot bet.

What Are Famous Examples of Longshots That Won?

Some of the most memorable moments in sports history involve longshot bets that came in against astronomical odds. These examples illustrate both the rarity and the emotional impact of successful longshots.

Sports Betting Longshots That Became History

Buster Douglas vs. Mike Tyson (1990): Mike Tyson was the undisputed heavyweight boxing champion and considered virtually unbeatable. Douglas was a 42-1 longshot. When Douglas knocked out Tyson in the 10th round, it sent shockwaves through the sports world. Anyone who had placed a £100 bet on Douglas would have won £4,200. The upset remains one of the greatest moments in sports history.

Miracle on Ice (1980): The United States Olympic hockey team faced the heavily favored Soviet Union during the Cold War. The Soviets were 1000-1 longshots to lose. When the US won 4-3, it became not just a sports victory but a cultural moment. A £100 bet would have returned £100,000. The victory transcended sports betting—it became a symbol of Cold War geopolitics.

Leicester City Premier League Win (2016): Leicester City started the 2015-16 season at 5000-1 odds to win the Premier League. After years of near-relegation, they defied all expectations to win the league. A £10 bet would have returned £50,000. This remains one of the most improbable outcomes in modern sports.

Why These Wins Matter

These longshot wins matter for several reasons beyond the financial payouts. First, they're statistically rare—that's why the odds are so long. Second, they generate enormous emotional impact and memorable stories. Third, they illustrate the gap between perceived probability (reflected in odds) and actual outcomes. Finally, they inspire future bettors, even though the mathematical reality is that such wins are exceptions, not the norm.

How Do You Calculate Implied Probability from Longshot Odds?

Understanding how to convert odds into implied probability is essential for evaluating whether a longshot bet offers value. Implied probability represents what the sportsbook believes is the true likelihood of an outcome occurring.

What is Implied Probability?

Implied probability is the percentage chance of an outcome winning, derived from the betting odds. It represents the sportsbook's assessment of true probability, adjusted for their built-in margin (the "vig"). For example, if a selection has implied probability of 2%, the sportsbook believes there's a 2% chance of that outcome occurring.

Implied probability is crucial because it allows you to compare the odds offered against your own assessment of probability. If you believe a longshot has a 5% chance of winning but the odds imply only 2%, you might consider it a value bet. Conversely, if you believe it has only a 1% chance but the odds imply 2%, it's a poor value bet.

Calculation Methods by Odds Format

For Decimal Odds: Implied Probability = (1 / Decimal Odds) × 100

Example: A 51.00 decimal odd

• Implied Probability = (1 / 51.00) × 100 = 1.96%

For Fractional Odds: Implied Probability = (Denominator / (Numerator + Denominator)) × 100

Example: A 50/1 fractional odd

• Implied Probability = (1 / (50 + 1)) × 100 = 1.96%

For American Odds (+): Implied Probability = (100 / (American Odds + 100)) × 100

Example: A +5000 American odd

• Implied Probability = (100 / (5000 + 100)) × 100 = 1.96%

Notice that all three formats yield the same implied probability (1.96%) for the same bet—they're simply different ways of expressing the same odds.

Why Implied Probability Matters

Implied probability matters because it reveals whether a bet is mathematically worthwhile. If you believe a longshot has a 3% true probability of winning, but the odds imply only 1.5%, that's a value bet—the odds underestimate the true likelihood. Over many bets, value bets generate positive expected value.

Conversely, if the odds imply 3% but you believe the true probability is only 1.5%, the bet has negative expected value—you'd lose money over time. Most longshot bets have negative expected value because the sportsbook's margin (typically 4-6%) is built into the odds, and longshots suffer from the favourite-longshot bias (discussed below).

What is the Favourite-Longshot Bias?

The favourite-longshot bias is one of the most well-documented phenomena in sports betting research. It describes a systematic mispricing in betting markets where longshots are overvalued and favourites are undervalued.

Understanding the Bias Phenomenon

The favourite-longshot bias refers to the empirical observation that betting odds provide biased estimates of true probability. Specifically:

• Longshots are overpriced — Their odds are longer than their true probability warrants, meaning they win less frequently than the odds suggest
• Favourites are underpriced — Their odds are shorter than their true probability warrants, meaning they win more frequently than the odds suggest

This bias has been documented across horse racing, sports betting, and casino games for decades. Academic research dating back to the 1980s has consistently shown that betting on favourites generates approximately -1% to -2% expected loss, while betting on longshots generates approximately -10% to -15% expected loss.

In practical terms: if you bet £100 on favourites over a long period, you'd expect to lose roughly £1-£2. If you bet £100 on longshots, you'd expect to lose roughly £10-£15. The difference is dramatic and statistically significant.

Why Does This Bias Exist?

The favourite-longshot bias exists due to a combination of psychological, behavioral, and market structure factors:

The Lottery Effect: Humans are attracted to low-probability, high-reward outcomes. This is the same psychological appeal that drives lottery ticket purchases. A longshot bet offers the fantasy of a massive payout from a small stake, which is psychologically appealing even if mathematically poor. Bettors willingly accept worse odds on longshots because of this emotional appeal.

Risk-Loving Behavior: Some research suggests that bettors exhibit risk-loving preferences for longshots specifically. They value the thrill and excitement of a potential upset more than the mathematical expectation would suggest is rational.

Availability Heuristic: When a longshot wins, it's memorable and widely discussed (like the Buster Douglas upset or Leicester City's Premier League win). These vivid examples make longshots seem more likely than they actually are. Bettors overweight recent memorable wins when assessing future longshot probability.

Public Bias: The general public disproportionately bets on longshots, particularly in casual betting contexts. This creates excess supply of longshot bets, which drives their odds longer (worse for the bettor) as sportsbooks adjust to manage their risk exposure.

Sportsbook Margin: Sportsbooks build a larger margin into longshot odds than favourite odds, knowing that longshot bettors are less price-sensitive and more motivated by the potential payout than the mathematical value.

Financial Impact of the Bias

The financial impact of the favourite-longshot bias is substantial. Research by academics including Erik Snowberg at Caltech has quantified the effect:

• Favourite bettors: Experience approximately -1% to -2% expected loss
• Longshot bettors: Experience approximately -10% to -15% expected loss
• Overall market: Longshots win less frequently than their odds suggest; favourites win more frequently

This means that if you were to place 100 bets of £10 each on longshots with -11% expected loss, you'd expect to lose approximately £11. The same 100 bets on favourites with -1.5% expected loss would cost you only £1.50. Over a year of betting, this difference compounds dramatically.

Is Betting on Longshots Ever Profitable?

The mathematical reality is sobering: longshots are statistically poor bets over the long term. However, this doesn't mean that longshot betting is never profitable—it requires skill, discipline, and a specific approach.

The Mathematical Reality

From a pure probability standpoint, longshots are worse bets than favourites. The favourite-longshot bias means that sportsbooks price longshots with larger margins than favourites. Academic research consistently shows that betting on longshots generates negative expected value, while betting on favourites generates slightly less negative expected value.

However, this doesn't mean every longshot is a poor bet. Some longshots may be mispriced—the odds might be longer than the true probability warrants, creating value. The challenge is identifying these mispriced longshots before placing your bet.

When Might a Longshot Have Value?

Longshots can have value in specific circumstances:

Mispriced Odds: If the sportsbook's odds are longer than the true probability, the bet has value. For example, if you believe a 50/1 longshot truly has a 3% chance of winning (rather than the 2% implied by the odds), that's a value bet. Over many such bets, you'd generate positive expected value.

Public Bias Inflating Odds: When the general public heavily bets on a favourite, sportsbooks adjust the odds to manage their risk. This can sometimes create value on the opposite side. If a team is heavily favored by the public but you believe the true probability is lower, the underdog (potentially a longshot) might offer value.

Line Movement Opportunities: Sportsbooks adjust odds based on betting action. If you identify a longshot where the odds have moved in your favor (become longer) due to public betting patterns, you might find value. Professional bettors often exploit these line movements.

Specific Knowledge or Analysis: If you have superior information or analytical insights about a specific event, you might identify longshots that the sportsbook has mispriced. For example, detailed injury analysis in sports betting might reveal that a longshot team is underpriced.

Bankroll Management for Longshot Betting

If you choose to bet on longshots, strict bankroll management is essential. Consider these principles:

Unit Sizing: Determine a "unit" as a percentage of your total bankroll (typically 1-2% for conservative bettors). Place only one unit on each longshot bet. This ensures that even a string of losses won't deplete your entire bankroll.

Realistic Expectations: Understand that you'll lose far more longshot bets than you win. If you place 50 longshot bets, you might win only 2-3 of them. Your unit sizing must account for this reality.

Loss Limits: Set a daily, weekly, or monthly loss limit. Once you reach it, stop betting. This prevents emotional decision-making and excessive losses.

Avoiding Chasing: Never increase bet sizes to recover losses. This is the primary path to bankruptcy in sports betting. Stick to your unit sizing regardless of recent results.

Diversification: Don't place all your bankroll on longshots. Most professional bettors focus on favourites and moderate underdogs where the expected value is better, using longshots as a small, speculative portion of their overall betting activity.

What Are Common Misconceptions About Longshots?

Several misconceptions about longshots persist among bettors. Understanding the reality behind these myths is important for making informed decisions.

Misconception 1: "Longshots Are Lottery Tickets"

The Myth: Longshots are just like lottery tickets—pure chance with no analytical advantage possible.

The Reality: While longshots do involve significant luck, they're not purely random like lottery tickets. Sportsbooks set odds based on data, analysis, and probability assessment. This means analytical skill can theoretically identify mispriced longshots. Some professional bettors do focus on finding value in longshots through detailed analysis, even though the overall category has negative expected value.

The distinction matters: you can't improve your odds of winning the lottery through analysis, but you potentially can improve your odds of finding value in longshots through research and analytical skill. However, the barrier to doing this profitably is extremely high, and most casual bettors lack the expertise.

Misconception 2: "One Big Win Erases All Losses"

The Myth: If you keep betting longshots, eventually you'll hit a big winner that erases all previous losses and generates profit.

The Reality: This is mathematically unlikely due to variance and expected value. Consider an example: you place 50 longshot bets of £10 each at 50/1 odds (total stake: £500). You might win 1-2 of them, generating £500-£1000 in winnings. However, you've lost £480-£490 on the other 48-49 bets. Your net profit is £0-£500 on a £500 investment—roughly break-even or slightly positive, depending on luck.

More realistically, if the odds are fairly priced or overpriced (as the bias suggests), your expected loss is approximately 10-15% of your total stake. One big win might offset some losses, but it won't eliminate the mathematical disadvantage of betting longshots with negative expected value.

The danger is that this misconception encourages chasing losses—placing increasingly large bets on longshots hoping for a big win to recover previous losses. This is a path to financial ruin.

Misconception 3: "Longshots Are Only for Desperate Bettors"

The Myth: Only people who are desperate or irrational bet on longshots.

The Reality: While casual, recreational bettors do disproportionately bet on longshots, some professional bettors strategically use longshots as a small portion of their overall portfolio. The key difference is discipline, bankroll management, and realistic expectations.

Professional value bettors might place 5-10% of their bets on longshots if they've identified specific value opportunities, while placing 90-95% on more favorable odds. They're not betting longshots for the thrill or hoping for a miracle—they're betting specific longshots they believe are mispriced based on their analysis.

Additionally, some bettors use longshots for specific purposes: building large parlay bets (multiple selections combined), or creating entertaining bets for small stakes without expecting long-term profit. These aren't "desperate" approaches—they're conscious decisions about entertainment value versus expected return.

How Do Longshots Compare to Outsiders and Underdogs?

The terms "longshot," "outsider," and "underdog" are sometimes used interchangeably in betting, but they have distinct meanings. Understanding the differences helps you communicate precisely about odds and probabilities.

Terminology Distinctions

Underdog: An underdog is any selection that's not the favourite—the selection considered less likely to win. Underdogs can have moderate odds (e.g., 2/1) or long odds (e.g., 50/1). The term is broad and encompasses everything from slight underdogs to extreme longshots.

Outsider: An outsider is similar to an underdog but often implies a selection that's not among the top contenders. In horse racing with 10 horses, the favourite might be 2/1, the second favorite might be 5/1, and the remaining horses might be considered outsiders. Outsiders typically have odds of 5/1 or longer but not necessarily extreme odds.

Longshot: A longshot is a specific subset of underdogs—the extreme underdogs with very long odds, typically 20/1 or longer. A longshot is always an underdog, but not every underdog is a longshot. A longshot is usually an outsider, but not every outsider is a longshot.

When to Use Each Term

Use "underdog" when you want to broadly describe any selection that's not the favourite. It's the most general term and works across all betting contexts.

Use "outsider" in horse racing contexts or when describing a selection that's not among the top contenders. It implies a larger field of competitors and suggests a selection that's far from the favourite.

Use "longshot" when you specifically mean a selection with very long odds (typically 20/1 or longer). It's more precise than "underdog" or "outsider" and clearly communicates that you're discussing an extreme underdog.

The distinction matters for clear communication. If you tell a fellow bettor "I'm backing an underdog," they might assume you're backing a selection at 3/1 odds. If you say "I'm backing a longshot," they'll understand you mean much longer odds, probably 20/1 or beyond.

FAQ: Common Questions About Longshots

Q: What counts as a longshot? Is there a specific odds threshold?

A: There's no universally agreed-upon threshold, but longshots are generally considered to be selections with odds of 20/1 or longer in fractional format (+2000 or higher in American format, 21.00 or higher in decimal format). In horse racing specifically, some define longshots as anything over 15/1. The key characteristic is that the implied probability is very low (typically 5% or less).

Q: Can you actually make money betting longshots?

A: Statistically, no—not over the long term. The favourite-longshot bias means that longshots have negative expected value of approximately -10% to -15%. However, if you can identify specific longshots that are mispriced by the sportsbook (where the true probability is higher than the odds imply), those individual bets might have positive expected value. The challenge is identifying mispriced longshots, which requires significant analytical skill.

Q: Why do sportsbooks offer such high odds on longshots if they're such poor bets?

A: Sportsbooks offer high odds on longshots because they know that bettors will bet on them regardless of the mathematical value. The favourite-longshot bias means that bettors are willing to accept worse odds on longshots due to the psychological appeal of a potential large payout. Sportsbooks profit by offering odds that are longer than the true probability warrants, capturing the difference as their margin.

Q: How do I find value in longshot bets?

A: Finding value in longshots requires: (1) Converting odds to implied probability, (2) Assessing the true probability based on your own analysis or research, (3) Comparing your assessment to the implied probability, (4) Betting only when your assessed probability is significantly higher than the implied probability. This requires expertise in the sport or event you're betting on and discipline to avoid betting longshots that don't meet your value threshold.

Q: What's the difference between a longshot and a parlay?

A: A longshot is a single bet on an unlikely outcome. A parlay is a bet that combines multiple selections, where all must win for the parlay to pay out. Parlays can include longshots, but they're not the same thing. A parlay of two 2/1 selections might pay 6/1 (similar to a longshot), but the mechanics are different. Parlays are sometimes called "accumulators" in UK betting.

Q: Should I ever bet on longshots?

A: That depends on your goals and risk tolerance. If you're seeking long-term profit, longshots are mathematically poor choices and should represent only a tiny portion of your betting activity. If you're betting for entertainment and can afford to lose your stake, small longshot bets can provide excitement and the potential for a memorable win. The key is treating longshot bets as entertainment expenses, not as a path to profit.

Related Terms

• Outsider
• Favourite
• Implied probability
• Underdog
• Odds
• Expected value