Atlanta United in MLS playoffs: A to Z guide

October 22, 2017. Josef Martinez reacts after scoring the second goal of the team for the lead but Toronto FC manage to tied the game by the end of the match.

Atlanta United will host Columbus in the first round of the MLS playoffs on Thursday at Mercedes-Benz Stadium.

For those new to the team, sport and league, here’s an A-to-Z guide:

A is for Atlanta. One of two expansion clubs to begin play this season. The other was Minnesota United. Atlanta United became the first MLS expansion club since Seattle in 2009 to qualify for the playoffs in its first year. It finished with 55 points. Minnesota United finished with 36 points.

B is for Ball. The league's official match ball this season is the Adidas Nativo. It mostly white, with panels that features parts of the flags of U.S. and Canada.

C is for Cap, Salary. Each team in MLS has a salary cap, but there are ways to circumvent the cap that are outlined in other letters of the A-to-Z. The cap in 2016 was $3.66 million and is $3.845 million this season. It really is more of a budget than cap because there are mechanisms that allow teams to spend more. Atlanta United has spent roughly $9.3 million on salaries, according to the MLS Player's Union salary database.

D is for Designated Player. These are the players whose salaries exceed $457,500 (toward the salary cap) if he starts to play at the beginning of the 2016 season, or $228,750 if he joined in the summer. There are also rules for Young Designated Players (23 or younger). The hit on the salary cap for these players was $200,000 for players ages 21-23, and $150,000 for 20 and younger. The DP rule was implemented in 2007 so that Los Angeles could sign David Beckham. Each team is allowed to sign as many as three Designated Players. Atlanta United's Designated Players are Josef Martinez, Miguel Almiron and Hector Villalba. They have combined to score 41 goals with 24 assists.

E is for Eastern Conference. The six teams from 11 that advanced to the playoffs were: Atlanta, Chicago, Columbus, New York City FC, New York Red Bulls, and Toronto.

F is for First round. The first round of the MLS playoffs is a one-round knockout game. Atlanta United will host Columbus and Chicago will host New York Red Bulls, Vancouver will host San Jose and Houston will host Sporting KC. The conference semifinals and finals are two-game, home-and-home series, and the MLS Cup is a one game event. Should Atlanta United advance to the MLS Cup, it will host the final because the host site is determined by the team that finished with the most points. Atlanta United finished with more (55) than the best team in the West.

G is for Garber, Don. He is the commissioner of the league, a job he has held since 1999.

H is for Homegrown Players. These are players that are signed by MLS players after they come up through the team's academy. Teams can sign as many as they want each year, but each team has 31 roster spots available. It is the equivalent of a farm system. Atlanta United has two Homegrown Players, Andrew Carleton of Powder Springs and Chris Goslin of Locust Grove, with three more joining in January.

I is for International. Each team starts with eight slots available to sign international players. They don't have to be used. They are also tradeable. Atlanta United has used eight international slots.

J is for Jersey sponsors. MLS was the first of the big 5 professional sports leagues in the U.S. and Canada to allow sponsors on the front of its jerseys. Other leagues are starting to follow. The contract details on the agreements are seldom disclosed, but the Galaxy's deal with Herbalife was reportedly $4.4 million per year. Atlanta United's kit is sponsored by American Family Insurance.

K is for Kit. A soccer jersey, shorts and socks is called a kit. Get used to it.

L is for the Landon Donovan MVP Award. Fifty-three players were nominated by the league's teams for this year's award. Voting closed on Monday. The winner will be announced Oct. 31. Miguel Almiron, Hector Villalba and Josef Martinez were Atlanta United's nominees.

M is for MLS Cup. This decides the champion of MLS. It is a one-game finale. Seattle defeated Toronto to win its first title. Los Angeles (five) has won the most. It will be played Dec. 9.

N is for Nemanja Nikolic. With 24 goals, the Chicago striker finished as the league's leading scorer to take the Golden Boot.

O is for Overtime. Overtime in soccer parlance is extra time and is used when the teams remain tied after 90 minutes plus whatever is decided is stoppage or injury time. It will be used in the playoffs.

P is for Penalty Kicks. They are awarded for fouls inside the penalty box, or area, and will also be used to decide outcomes if games finish tied. The penalty spot is 12 yards from the goal line. Penalty shootouts are best-of-five. If the teams remain tied, the penalty kicks go into sudden death mode and will continue until a player on one team makes one and a player on the other team misses.

Q is for Quality. The quality of the play in MLS is a constant debate. Thought it can't match the world's best leagues such as in England, Spain, Italy and Germany, it in improving incrementally each year.

R is Referees. There are many debates about the quality of the refereeing in the league. Atlanta United's Gerardo Martino has not been shy about criticizing the officials. Real Salt Lake's Mike Petke went on an epic rant about the refs.

S is for Supporters' Shield. This is given to the team that finishes the regular season with the most points. Toronto won the Supporters' Shield and is the top seed in the Eastern Conference.

T is for Timbers, the nickname for Portland. They finished as the top seed in the Western Conference with 53 points. They are led by Diego Valeri, the league's likely MVP when voting results are announced.

U is for Unimas, one of the TV networks that will broadcast the MLS playoffs. ESPN2 will broadcast Atlanta United's game against Columbus. Fox Sports is also a broadcaster.

V is for VAR. The league started using Video Assistant Referees this season to aid the on-field officials. Atlanta United has experienced several episodes with VAR, including a penalty kick against Toronto.

W is for Western Conference. There are 11 teams comprising this group: Colorado, Dallas, Houston, Los Angeles, Minnesota, Portland, Real Salt Lake, San Jose, Seattle, Sporting Kansas City and Vancouver. Those who made the playoffs are Portland, Seattle, Vancouver, Houston, Sporting KC and San Jose.

X is for Expansion. The league wants to reach 28 teams by 2024. Twelve cities put in applications for the final four slots. They were Sacramento, San Diego, Phoenix, Detroit, Indianapolis, St. Louis, Tampa Bay/St. Petersburg, Nashville, San Antonio, Raleigh, Cincinnati and Charlotte.

Y is for Yellow cards. A yellow card is given typically when a player is more aggressive than necessary. Two yellow cards equal a red card and the player is sent off, reducing his team to 10 men on the field.

Z is for Zero. Teams get zero points for a loss, one for a tie and three for a victory. There will be no ties in the first round of championship game of the playoffs because penalty kicks will be used. There can be ties in the second and third rounds because those are two-game series, but if the two teams are tied on aggregate goals after both legs, penalty kicks will be used to decide which team advances.