(NewsNation Now) — The legal sports betting industry is exploding in the United States. There are now nearly 20 states with legal betting markets, and the companies are seeing green after the biggest city in the country, New York, just turned on mobile sports wagering this month.

It’s opened up the doors to people who’ve never tried it before. And those people may not quite understand the language of sports betting.

Johnny Avello, director of the race and sportsbooks for DraftKings, said the name of the game for his staff is to entice up equal amounts of money on each betting option.

“Odds makers don’t necessarily pick winners. We try to put up a line where we get equal action,” Avello said on “The Donlon Report.”

This coming weekend the Kansas City Chiefs and Cincinnati Bengals will play for one berth in the Super Bowl, and the San Francisco 49ers will take on the St. Louis Rams for the other ticket to the big game.

The graphic above shows the point spreads, moneyline odds and over/under numbers for the games. Not sure what any of it means? Here’s an explanation.

Point spreads

The Kansas City Chiefs are favored by 7 points against the Bengals. The favorite is always denoted with a “-” symbol. That means oddsmakers such as Avello, expect the Chiefs to win the game by around that number. However, the spread is factored into the real score to determine who wins the bet.

Say the Chiefs beat the Bengals this Sunday by the score of 28-20. In this scenario, the Chiefs won by more than 7 points, meaning they covered the spread. People who bet on the Chiefs -7 would collect their bet.

However, if the Chiefs beat the Bengals 28-24 then they did not cover the spread because they did not win by more than 7. In this case, people who bet the Bengals +7 would collect.

But what if the Chiefs win the game 27-20? Then nobody wins or loses and the bets are refunded.

The odds on points spreads are usually 1.1:1, meaning an $11 bet would win $10, for a total of $21 being paid to the winning bettor.

As Avello said, the idea of the oddsmakers is to set this line at a number that brings in an even amount of money on both sides of it. He and others in his industry use mathematical modeling to come up with the number.

This season, betting with the underdog on the points spread was the right call 52.3% of the time, according to records kept on covers.com.

Moneyline

If that points spread stuff is confusing, the moneyline might be more your speed. It’s a simple question: Who’s going to win?

However, the odds on moneyline bets are far less predictable and depend on the expected outcome. For example, the Chiefs odds above say -350. That means you would have to bet $350 to win $100, plus your bet is returned, for a total payout of $450. The Chiefs are heavy favorites.

What about the “+” sign next to the Bengals 280? That means they’re the underdog, and a bet on them would pay a lot more because the oddsmakers expect them to lose. In this case, betting $100 would win $280, plus your bet is returned, for a total of $380.

The steep odds on favorites are why many people choose to bet with points spreads. Only 37.5% of underdogs won for moneyline bettors this season.

Totals bets (over/under)

What are those numbers that have decimal points in them? The total bet, also known as the over/under, is all about how many points the two teams will combine to score during the game.

The Chiefs/Bengals game is set at 54.5. How could a team score half a point? They can’t. The reason there’s a half point is so the bet does not end in a tie, which is known as a push.

If the Chiefs win 35-20, the over bet would cash since that score adds up to 55. That number is above, or over, 54.5. However, if their kicker misses an extra point on a touchdown and it’s 34-20 then the under would win since it now adds up to 54.

The odds on totals, similar to points spreads, are usually 1.1:1. An $11 bet would win $10, for a total of $21 being paid to the winning bettor.

If you like a lot of points, it may disappoint you to learn that the under was the correct side in 54.1% of games this season.

How do you choose what to bet on?

That’s entirely up to you. As Avello said on “The Donlon Report,” “We just put [the odds] up and just hope the customers enjoy what we do.”

If you’re wondering who to pick in this weekend’s conference championships, Avello said he would lean with the Chiefs, but the 49ers vs. Rams game is “totally random” and he didn’t have a confident prediction.