Underdog Betting Strategy
Complete guide to betting underdogs profitably in sports betting
What is an Underdog in Betting?
An underdog is the team, player, or fighter expected to lose according to the betting odds. Underdogs are identified by:
- Positive odds in American format (+150, +200, +300)
- Decimal odds above 2.0 (2.50, 3.00, 4.00)
- Fractional odds where numerator > denominator (3/2, 2/1, 5/1)
Example:
Lakers vs Celtics game:
- Lakers -180: Favorites (expected to win)
- Celtics +160: Underdogs (expected to lose)
If you bet $100 on the Celtics underdog and they win, you profit $160.
Why underdogs exist:
- Team/player skill difference
- Home court advantage for opponent
- Recent poor performance
- Injuries to key players
- Public perception and media narratives
Why Bet Underdogs?
The Public Overbets Favorites
Casual bettors love betting favorites. This creates two problems:
- Favorites get overbet, pushing odds down (less value)
- Underdogs get underbet, keeping odds high (more value)
This is especially true for:
- Popular teams (Cowboys, Lakers, Yankees)
- Star players (LeBron, Mahomes, Ohtani)
- Teams on winning streaks
- Primetime games with casual viewership
Higher Payouts, Less Volume Needed
You don't need to win as often with underdogs to be profitable.
Example Comparison:
Favorite betting:
- Bet $150 to win $100 (-150 odds)
- Need 60% win rate to profit
- 10 bets = 6 wins needed
Underdog betting:
- Bet $100 to win $150 (+150 odds)
- Need 40% win rate to profit
- 10 bets = 4 wins needed
Underdogs Win More Than Odds Suggest
Historical data shows underdogs win more frequently than implied probability in several sports:
- NFL home underdogs: Cover spreads ~52-53% (should be 50%)
- MLB underdogs: Win ~45% (often priced at 38-42%)
- NHL playoff underdogs: Win ~42% (often priced at 35-38%)
- UFC underdogs: Win ~35-37% (often priced at 30-33%)
When to Bet Underdogs
1. Divisional Games
Teams that play each other multiple times per season know each other well. This familiarity reduces the favorite's edge.
- NFL: Divisional underdogs cover more often
- MLB: Division games more unpredictable
- NBA: Rivalries create motivated underdog performances
2. Home Underdogs
Playing at home provides advantages even for weaker teams:
- Crowd support and energy
- Familiar environment (court, field, altitude)
- No travel fatigue
- Referee/umpire home bias (slight but exists)
NFL home underdogs are one of the most profitable betting angles in sports.
3. Look-Ahead Spots
When a favorite has a big game coming up next week, they may overlook the current underdog opponent.
Example: Team A plays Team B (underdog) this week, but has rival Team C next week. Team A might not be fully focused, creating value on Team B.
4. Rest Advantage Underdogs
Underdogs with more rest than favorites offer value:
- NBA team off 3 days rest vs opponent on back-to-back
- NFL team off bye week vs short-week opponent
5. Public Darlings as Favorites
When popular teams are favorites, the line is often inflated by public money. Their opponent becomes undervalued.
Prime examples:
- Dallas Cowboys in primetime
- New York Yankees in playoffs
- Los Angeles Lakers with LeBron
6. Motivation Discrepancy
Underdogs in must-win situations (elimination games, playoff seeding) often outperform expectations against already-clinched favorites.
Sport-Specific Underdog Strategies
NFL Underdog Betting
Best underdog spots:
- Home underdogs of 3 points or less
- Divisional home underdogs
- Teams off bye week as underdogs
- Playoff underdogs (higher variance)
Avoid:
- Huge underdogs (+14 or more) unless specific situation
- Primetime public darlings as favorites (overvalued lines)
MLB Underdog Betting
Best underdog spots:
- Starting pitcher matchup favors dog
- Day games after night games
- Home underdogs in division games
- Underdogs against overvalued aces
MLB has high variance and lower favorite win rates than other sports, making selective underdog betting profitable.
NBA Underdog Betting
Best underdog spots:
- Rest advantage (3+ days rest vs back-to-back opponent)
- Playoff-motivated underdogs vs resting favorites
- Home underdogs in rivalry games
Note: NBA has more dominant favorites due to star players. Underdog betting is less profitable than NFL/MLB but still has spots.
NHL Underdog Betting
Best underdog spots:
- Playoff underdogs (goaltending can steal series)
- Home underdogs against tired opponents
- Hot goalie on underdog team
UFC/MMA Underdog Betting
Best underdog spots:
- Skilled wrestler as underdog vs popular striker
- Undefeated prospects with bad style matchup
- Lesser-known skilled fighters vs fading names
- Grappler underdogs vs one-dimensional strikers
See our UFC Betting Guide for more details.
Profitable Underdog Systems
System 1: NFL Home Underdogs
Rules:
- Bet all NFL home underdogs of +3 to +7
- Against the spread, not moneyline
- Historically covers 52-53%
System 2: MLB Underdog ML Betting
Rules:
- Bet underdogs of +110 to +180
- Moneyline only
- Focus on divisional games
- Historically wins ~43-45% (needs ~42% to profit at these odds)
System 3: Reverse Line Movement Dogs
Rules:
- Find underdogs whose line is moving in their favor
- Despite most public bets on the favorite
- Indicates sharp money on the dog
Learn more: Reverse Line Movement Guide
Underdog Betting Tips
1. Don't Bet All Underdogs
Blindly betting every underdog loses money. Be selective and look for specific value situations.
2. Avoid Huge Underdogs
+400 or higher underdogs are usually that price for a reason. Focus on +120 to +250 range where underdogs have realistic chances.
3. Track Public Betting Percentages
When 75%+ of bets are on the favorite but the line isn't moving toward the favorite, sharp money is on the dog.
4. Use Proper Bankroll Management
Underdog betting has variance. Don't bet more than 1-3% of your bankroll per bet to survive losing streaks.
5. Compare Odds Across Books
Underdog odds can vary significantly. Shop for the best price. +160 vs +140 is a big difference in value.
6. Focus on Situational Spots
Don't just bet dogs because they're dogs. Look for specific situations: motivation, matchups, rest, travel, etc.
Common Underdog Betting Mistakes
❌ Mistake 1: Betting Every Underdog
This is gambling, not strategy. You need edge, not just higher payouts.
❌ Mistake 2: Chasing Big Payouts
+500 underdogs are lottery tickets. They rarely win and destroy your bankroll with losses.
❌ Mistake 3: Ignoring Why They're Underdogs
Sometimes teams are underdogs for very good reasons (injuries, horrible matchup, tanking). Not all dogs have value.
❌ Mistake 4: Not Tracking Results
Underdog betting requires tracking to see if you're actually profitable. Gut feelings don't cut it.
❌ Mistake 5: Overbetting Due to Payouts
Higher odds tempt larger bets. Stick to your unit sizing regardless of dog or favorite.
Underdogs vs Favorites: Which is Better?
| Factor | Underdogs | Favorites |
|---|---|---|
| Payouts | Higher ($100 → $150+) | Lower ($150 → $100) |
| Win Rate Needed | Lower (40-45%) | Higher (55-60%) |
| Variance | Higher (more swings) | Lower (steadier) |
| Public Betting | Underbet (value) | Overbet (less value) |
| Best For | Value-seeking bettors | Consistency-seeking |
The truth: Neither is inherently better. The key is finding value, whether it's on underdogs or favorites. But public bias creates more frequent value on underdogs.
Calculating Underdog Value
Implied Probability Method
Compare the odds' implied probability to your estimated true probability.
Example:
Underdog at +150 odds:
- Implied probability: 100 / (150 + 100) = 40%
- Your estimate: 48% chance of winning
- Edge: 48% - 40% = 8% edge
- Result: +EV bet, take it!
Use our Implied Probability Calculator and Expected Value Calculator for quick calculations.
Break-Even Win Rate
Calculate the minimum win rate needed to profit at given odds:
- +100 odds: Need 50% win rate
- +150 odds: Need 40% win rate
- +200 odds: Need 33.3% win rate
- +300 odds: Need 25% win rate
If you estimate the underdog wins more than the break-even rate, you have value.
Key Takeaways
✓ What Underdogs Are:
- Expected to lose (positive odds, > 2.0 decimal)
- Higher payouts, lower win rates needed
- Often undervalued by public betting
✓ Best Underdog Spots:
- NFL home underdogs (+3 to +7)
- MLB divisional game underdogs
- Home underdogs in any sport
- Look-ahead spots (favorite distracted)
- Rest advantage underdogs
- Reverse line movement dogs
✓ Avoid:
- Massive underdogs (+400+) without specific reason
- Betting all underdogs blindly
- Underdogs with key injuries
- Teams tanking for draft position
✓ Keys to Success:
- Be selective, not systematic
- Track public betting percentages
- Compare implied vs true probability
- Use 1-2% unit sizing (variance is higher)
- Focus on +120 to +250 range
Find underdog value automatically. FairOdds Terminal identifies +EV opportunities on underdogs across all sports and bookmakers.
FAQ: Underdog Betting
What does underdog mean in betting?
An underdog is the team or player expected to lose according to betting odds. Underdogs have positive odds (+150, +200) in American format or odds above 2.0 in decimal format. Betting $100 on an underdog at +150 wins $150 profit if they win.
Is it smart to bet on underdogs?
Yes, when there's value. Underdogs win more often than their odds suggest in many sports. The public overvalues favorites, especially popular teams, creating profitable underdog opportunities. The key is identifying which underdogs are undervalued, not betting all underdogs blindly.
What is the underdog betting strategy?
Underdog betting strategy involves identifying situations where the public overreacts to recent performance, team popularity, or media narratives, creating inflated favorite prices. Bet underdogs when they have better chances than odds imply, focusing on situational spots like divisional rivalries, look-ahead games, and home underdogs.
Do underdogs win more than expected?
In many sports, yes. NFL home underdogs cover spreads over 50% of the time historically. MLB underdogs win roughly 45% of games while odds suggest they should win 40%. This edge exists because the public overbets favorites, creating value on dogs.
What sports are best for underdog betting?
NFL (especially home underdogs), MLB (high variance, many dog wins), NHL (playoff underdogs), and UFC/MMA (35%+ upsets) offer consistent underdog value. NBA has fewer profitable underdog situations due to star player dominance.
Should I bet big underdogs or small underdogs?
Small to medium underdogs (+120 to +200) offer better risk-reward than huge underdogs (+400+). Big underdogs have lower win probability and higher variance. Focus on dogs with realistic win chances, not lottery tickets.
How do you find value in underdog bets?
Look for situations where public perception diverges from reality: divisional games with familiarity, teams on winning streaks facing overconfidence, look-ahead spots where favorites focus on next opponent, and home underdogs with specific matchup advantages.
Can you make money betting only underdogs?
Yes, but selective underdog betting is key. Blindly betting all underdogs loses money. But systematically betting underdogs in specific situations (NFL home dogs, MLB day games, divisional matchups) can be profitable long-term with proper bankroll management.