There are certain terms that are fundamental to understand before you start betting – and underdog is one of them. 

How to identify the underdog, along with the favorite, is crucial before you even start to look at the types of bets available. 

An underdog is the team or individual that the sportsbook expects to lose. 

What does Underdog mean?

When a sportsbook releases a market on an event, generally speaking, one side is the underdog, and the other is the favorite.

Very simply put – the favorite is expected to win; the underdog is expected to lose. 

The two sports bets that best encompass the notion of favorite versus underdog are the moneyline and point spread.

Let’s take a look at each in turn.

Backing the Underdog on the Moneyline

In a moneyline bet, backing the underdog means you are placing your wager on the team or individual that the sportsbook believes is more likely to lose. 

As a result, a winning bet will pay out substantially more than a winning bet on the favorite.  

To understand how that works, we need to take a look at the odds.

How do I know who the Underdog is?

When a moneyline is released, the bookmaker declares opening odds on each side of the bet, or market. 

The underdog always carries plus odds and the favorite always carries minus odds. 

Learn more comprehensively about American odds here.

Let’s use this Thanksgiving Weekend’s match-up between the Dallas Cowboys and Las Vegas Raiders to illustrate. Here’s how the NFL moneyline appears at the Caesars Sportsbook online.

Raiders vs Cowboys Moneyline Caesars Nov26 2021

The underdog, Las Vegas, appears with plus odds of +280.

The favorite, Dallas, appears with minus odds of -350.

At +280, a winning $100 bet on the Raiders would give you a payout of $380 – your $100 initial stake, plus $280.

Three-way money lines

Some sports command a three-way money line – usually those that are low-scoring and where tied matches happen fairly frequently. Soccer is the best example.

Often when two teams meet the most likely outcome is actually the draw, so in this instance the odds-implied “favorite”position does not actually mean the match winner.

Learn more comprehensively about Moneyline bets here.

Backing the underdog on a Point Spread

The ingenious notion of a point spread was the invention of sportsbooks as a means to level the betting field between two mis-matched sides.

Whereas the moneyline is a bet on the winner of an event, a spread bet is a bet on the margin of victory. 

The spread boosts the underdog by giving it plus points ahead of the game and a winning bet on the underdog gives your team the leeway to still lose, so long as it is still within the margin of the spread. 

Again, the underdog carries the (+) and the favorite the (-). The spread itself gives you the expected margin of victory. The wider the spread, the greater the perceived gulf between the two teams.

In this game, the Raiders are +7.5 point underdogs to Dallas. At -110 on both sides, the odds pay out the same on a winning bet.

Raiders vs Cowboys Spread Caesars Nov26 2021

For a spread bet to win, your team needs to “cover the spread”. The Raiders cover the spread if they lose by no more than 7 – or indeed cause an upset and win.

Learn more comprehensively about Point Spreads here.

Hidden value between the moneyline and spread? 

Although moneyline and point spread markets are structured differently, the premise is identical – that one team is stronger than the other, and the line is set at a point at which the sportsbook feels makes either side of the market equally attractive to bettors.

If there is any discrepancy between the moneyline and spread markets, this can be a good way to find value in the odds.

You can use The AllStar’s Moneyline Converter to check if there might be any on offer. 

What is a Pick’em?

There is the rare and odd occasion when a sportsbook is unable to decide which team should be the underdog. When this happens, the moneyline does not assign minus or plus odds.

Instead, these are “pick’em”, or “pick” markets (usually displayed by sportsbooks as “PK”) because, well… what the hell – just pick one. 

The moneyline on each side is identical, and spreads are zero.

That siad, it’s important to remember that picks still carry vig, or juice, and it doesn’t mean that the sportsbook sees the teams equally, just that it sees both teams as having an equal chance of bagging the win on the day.

Is it better to bet on the underdog?

If there was an easy answer to this, we’d be sitting on a beach somewhere enjoying the spoils of our successful sports betting career… 

Unfortunately though, there is no easy answer to this. The answer to questions like this usually depends on what it is you’re looking to achieve from your betting experience.

Fancy a Hail Mary on an underdog in a big game? Then why not back the +2500 outsider and pray – that would be a $2500 win on a $100 punt.

Afterall, some of the greatest moments in sports have come from the upsets.

But if you’re looking to maintain a profitable long-term sports betting career, managing your bankroll is key – and long outside shots hoping for big pay-days probably won’t get you there.

That said, there are times when backing the underdog can be beneficial:

  • On a moneyline that isn’t too wide, if you believe an upset is possible.
  • If you feel a point spread is too generous, suggesting the underdog could lose but cover the spread. Or where the favorite might win, but not by as much as the spread suggests.

Once you become more experienced as a sports bettor, there are strategies out there where betting on the underdog is an integral part of helping you grow your bankroll. For the novice however, a simple strategy like flat betting might be more suitable.


To recap, here are the important things to remember about underdogs:

  • In American odds, they carry plus odds.
  • You need to risk less to win more when you back them.
  • A point spread benefits them. They can still lose and cover the spread.

What happens to my underdog bet if the favorite wins?

That depends on the type of bet you placed. If it was a moneyline bet and the favorite wins, your bet loses.

If you laid a spread bet, and the favorite wins the game, be sure to check against the points spread because a favourite can win the game but fail to cover the spread. In baseball, this is also true of +1.5 run lines.

Is there a MLB underdog betting system?

Sharp bettors who have played the field for years are likely to have their own approach to any given game. In sports betting there is no one-size-fits all solution.

That said, based on the last five seasons up to 2020, MLB is the sport that statistically has the highest percentage of moneyline underdog wins, at 41.6%. This hasn’t gone unnoticed, as so there is legitimate talk about backing the underdog in MLB.

In second spot is the NHL, at 41.4%, with the UFC third at 35%. Be sure to check out our extensive MMA betting guide if you’re interested in wagering on the fight scene.

Is there an NFL underdog betting system?

Again, there’s no overarching strategy to suit all, but in the NFL, as illustrated above, the method to back the underdog is usually via the spread versus the moneyline.

However, digging deeper into the data shows that historically there are profitable strategies that could have been employed – such as backing the visiting underdog when the spread has been between +2.5 and +6.5 points.

Consistent three-putter, chip-duffer and rough-finder; suffers from extreme fade. One of The AllStar content guys. Loves/hates that one flush shot that keeps him coming back for more.