Betting 101: A Beginner’s Guide to Sports Betting

Sports betting has a funny way of looking much more complicated than it actually is.

Open a sportsbook for the first time and you get buried in plus signs, minus signs, spreads, totals, props, alternate lines, parlays and 400 different ways to bet on a Tuesday night basketball game.

The basic idea is much simpler.

Betting 101 starts here: you are picking an outcome, deciding whether the price is worth betting and risking money based on that opinion.

Everything else is just learning how the different bets work and, eventually, figuring out when the sportsbook might be wrong.

Betting 101: How Does Sports Betting Work?

A sportsbook creates betting markets around sporting events.

You might bet on:

• Who wins the game
• How much a team wins or loses by
• How many points are scored
• Whether a player goes over or under a statistical number
• A future result, like winning a championship
• Multiple outcomes combined into one bet

Every wager also comes with odds.

Those odds matter just as much as the pick itself because they determine both how much you can win and roughly how likely the sportsbook believes that outcome is to happen.

Being right about the game isn’t enough.

You also have to be right at the price you’re being offered.

That distinction is basically where sports betting strategy begins.

How to Read Betting Odds

If you’re betting in the United States, you’ll commonly see American odds.

They look like this:

-110

or

+150

DraftKings currently uses American odds as its default format, although other formats can also be selected. 

Here’s the easiest way to read them.

Negative Odds

A negative number tells you how much you would need to risk to make $100 in profit.

At -110, you would risk $110 to win $100.

If the bet wins:

• $100 profit
• Your $110 stake comes back
• $210 total returned

You do not actually have to bet $110. The sportsbook calculates the same ratio whether you’re betting $5 or $500.

Positive Odds

A positive number tells you how much profit you’d make from a $100 wager.

At +150, a $100 bet would make $150 in profit.

You’d receive:

• $150 profit
• Your $100 stake back
• $250 total returned

Generally, negative odds indicate the more likely side while positive odds indicate the less likely side.

But don’t fall into the trap of thinking favorite = good bet or underdog = bad bet.

The price is the whole point.

The Moneyline

The moneyline is the simplest major bet.

You’re picking who wins.

That’s it.

If Boston is:

Boston -150

and New York is:

New York +130

Boston is the favorite. New York is the underdog.

Bet Boston and you need Boston to win.

Bet New York and you need New York to win.

No style points. No margin of victory. No need to explain why the coach should be fired afterward.

Just win the game.

The odds tell you what you’re paying for that outcome. DraftKings describes the relationship similarly: larger positive moneyline odds offer more potential profit but correspond with a lower implied probability, while increasingly negative odds require more risk for the same $100 profit target. 

What Is the Point Spread?

The spread adds a handicap to the game.

Let’s say the line is:

Philadelphia -3.5
Dallas +3.5

If you bet Philadelphia -3.5, Philadelphia needs to win by 4 or more.

If you bet Dallas +3.5, Dallas can:

• win the game outright
• lose by 1
• lose by 2
• lose by 3

and your bet still wins.

DraftKings defines the spread as a handicap applied to each side of the matchup. 

This is why you’ll occasionally find yourself cheering like hell for a team to lose by three.

Sports betting does strange things to otherwise normal people.

Why the Half Point Matters

Notice that example used 3.5 instead of 3.

That half point eliminates the possibility of a tie against the spread.

If you instead bet a team at -3 and it wins by exactly three, the wager can result in a push, depending on the market rules. Your original stake is generally returned rather than the bet being graded as a win or loss.

That’s why moving from -3 to -3.5 isn’t some meaningless little decimal.

It changes the bet.

What Is an Over/Under?

The total, usually called the over/under, is a bet on the combined result rather than which team wins.

Suppose an NFL game has a total of:

47.5

You can bet:

Over 47.5

or

Under 47.5

If the final score is 28-24, that’s 52 total points.

Over wins.

If the final is 20-17, that’s 37.

Under wins.

You could be completely wrong about which team is better and still win the bet because the only thing that mattered was total scoring. DraftKings currently lists over/under betting as one of its core betting formats. 

What Are Player Props?

Player props let you bet on an individual player’s performance rather than the final game result.

Examples:

Quarterback passing yards

• Over 274.5
• Under 274.5

NBA player points

• Over 24.5
• Under 24.5

MLB pitcher strikeouts

• Over 6.5
• Under 6.5

This is where sports knowledge can become especially useful because you’re narrowing the question.

Instead of asking:

Who wins this game?

you might be asking:

Is this running back going to get enough carries to clear 67.5 rushing yards?

That can involve matchup, injuries, expected role, game script, recent usage and the price the sportsbook is offering.

Props are also an area where news matters a ton.

A teammate getting ruled out can completely change another player’s expected workload.

What Is a Parlay?

A parlay combines multiple bets into a single wager.

For example:

• Patriots moneyline
• Celtics -4.5
• Red Sox over 4.5 team runs

All three become one bet.

The attraction is obvious. Combining outcomes produces a larger potential payout.

The catch is equally obvious.

Every leg generally has to win.

If two bets hit and the third one dies in spectacular fashion with 14 seconds remaining, congratulations on your collection of two correct predictions and zero dollars.

DraftKings defines a parlay as a wager involving multiple outcomes where all included legs must be selected correctly for the parlay to win. 

Parlays can be fun.

They can also trick new bettors into thinking a giant payout means a good bet.

Those are not the same thing.

Straight Bets vs. Parlays

For someone learning how to bet, I’d spend most of my time understanding straight bets first.

A straight bet is one individual wager.

One spread.

One moneyline.

One total.

One prop.

It makes evaluating your decisions much easier.

If I bet one NBA spread and lose, I can go back and ask whether my reasoning was bad.

If I build a 12-leg parlay involving the Korean Baseball Organization, Connor McDavid shots on goal and the second half of a college basketball game I didn’t know existed until nine minutes ago, the postmortem gets a little more complicated.

Learn to make one good bet before worrying about connecting six of them.

What Is the Vig?

The sportsbook isn’t running this thing as a public service.

The vig, also called the juice, is effectively the cost built into the market.

A common example is seeing both sides of a spread priced around:

-110

If you bet $110 and win, you make $100.

If the sportsbook simply offered perfectly even 50/50 bets at +100 on both sides, it would not have the same built-in advantage.

That gap matters over hundreds or thousands of wagers.

We’ll cover this much more deeply in our guide to vig, juice and implied probability, because understanding price is one of the biggest jumps from casually picking winners to actually understanding sports betting.

What Is a Unit?

You’ll hear bettors talk about being:

1 unit on a bet

or

2 units on a bet

A unit is simply a standardized amount used to measure wagers.

If your unit is $10:

• 1 unit = $10
• 0.5 units = $5
• 2 units = $20

Someone else’s unit might be $25 or $100.

That’s why saying “I won five units this month” is more useful than saying “I won $500.” It gives context without everyone needing the same bankroll.

For beginners, the important part isn’t finding some magical unit size.

It’s keeping wagers small enough that one terrible Sunday doesn’t have you staring at the ceiling at 2:30 in the morning reconsidering several life decisions.

What Is Bankroll Management?

Your bankroll is the money you’ve specifically set aside for betting.

Not rent money.

Not grocery money.

Not the emergency fund.

Betting money.

One of the worst habits a new bettor can develop is changing wager size based on emotion.

Lose three bets?

Bet bigger to get it back.

Win four?

Apparently you’ve solved sports forever, so naturally it’s time to triple the next wager.

That’s how a hobby turns stupid quickly.

A much better approach is deciding what your normal bet size is ahead of time and staying reasonably consistent.

There is variance in sports betting.

A good bet can lose.

A terrible bet can win.

One result does not prove whether the decision was good.

What Is Line Movement?

Betting lines change.

You might see an NFL team:

-2.5 on Monday

and then:

-3.5 on Sunday

That can happen for many reasons, including new information, injuries and betting-market activity.

Why does it matter?

Because your number matters.

If I like a favorite at -2.5 and somebody else bets the same team at -3.5, we technically made different bets.

That one point could be the difference between winning and losing.

Eventually you’ll hear people talk about closing line value, commonly shortened to CLV.

We don’t need to turn Betting 101 into a semester-long economics course, but remember this:

Don’t just ask what you want to bet. Ask what number you’re willing to bet it at.

What Is Live Betting?

Live or in-game betting allows wagers after the game has already started.

The odds and lines update as the event changes. DraftKings currently offers live in-game betting markets as part of its sportsbook. 

A football favorite that was -7 before kickoff might become +3 after falling behind early.

A basketball total can move dramatically after a hot or cold start.

Live betting gives you more information because you’ve actually seen part of the game.

It also gives you substantially less time to think.

That’s not always a great trade.

If you’re new, there is absolutely nothing wrong with learning pregame markets before deciding you need financial exposure to the fourth quarter of Kings-Jazz at midnight.

Five Mistakes I’d Avoid as a New Sports Bettor

1. Betting a Team Because You Think They’ll Win

Winning isn’t enough.

If a team has a 70% chance of winning but the price requires them to win far more often than that for your bet to make sense, you may still have a bad wager.

Sports betting is about probability and price, not just picking winners.

2. Chasing Losses

The 4 p.m. games do not know that you lost the 1 p.m. games.

You are not “due.”

Increasing your wagers because you’re pissed off is not a betting system.

3. Betting Everything

You don’t need action on 14 games because 14 games are available.

Sometimes the best slate has five bets.

Sometimes it has one.

Sometimes nothing looks particularly good.

The sportsbook will still be there tomorrow.

4. Falling in Love With Parlays

A +1400 payout looks sexy.

That doesn’t automatically make it valuable.

Parlays require multiple things to go right and sportsbooks are extremely good at making that big potential payout look irresistible.

Learn straight bets first.

5. Ignoring the Number

“I like Buffalo” isn’t a complete betting opinion.

Buffalo -2.5?

Maybe.

Buffalo -7?

That’s a completely different conversation.

The team can stay the same while the bet gets worse.

What Actually Makes a Good Sports Bet?

A good bet is not simply one that wins.

That sounds insane the first time you hear it.

It’s also one of the most important things to understand.

Say you repeatedly bet outcomes that truly have a 60% chance of happening while getting a price that suggests the probability is closer to 50%.

You’re going to lose plenty of those wagers.

Forty percent of them, in theory.

But you’d still want to keep making that kind of bet.

The goal is to find situations where your estimate of the true probability is better than the probability reflected in the market price.

That’s called value.

Finding it consistently is the hard part.

Where I’d Start

If you’re completely new to betting, learn in this order:

1. Understand American odds.
2. Learn moneylines.
3. Learn spreads.
4. Learn totals.
5. Understand the difference between profit and total payout.
6. Learn basic bankroll management.
7. Learn player props.
8. Understand vig and implied probability.
9. Learn why line movement matters.
10. Worry about advanced betting strategy after that.

And don’t feel like you need to have money on every game to enjoy sports betting.

The goal isn’t action for the sake of action.

It’s finding a number where you think the sportsbook has it wrong and being willing to back that opinion.

Sometimes you’ll be right.

Sometimes the kicker will hit the upright.

Welcome to sports betting.