The addition of a new tournament to the ATP calendar set tongues wagging when it was announced in November 2018.

That event, named the ATP Cup, is now upon us, but what exactly is it?

If you need to get up to speed with the who, what, where, when, why and how, look no further.

Read on to find out everything you need to know about the ATP Cup.

WHAT IS IT?

Described by the ATP as "the most exciting new tournament in tennis", it features 24 nations represented by between three and five male players.

WHERE IS IT?

Australia will host the event across three cities: Sydney, Brisbane and Perth.

WHEN IS IT?

The action starts on January 3 and concludes with the final nine days later.

WHO IS PLAYING?

Rafael Nadal and Novak Djokovic are two of the nine top-10 players in the line-up, with Roger Federer the odd one out.

WHAT ARE PEOPLE SAYING ABOUT IT?

"This is going to bring together a lot of nations and for me personally it will be a very nice and proud moment to represent my country." - Novak Djokovic

"We are not taking this competition like preparation for another one, even if the Australian Open is around the corner. It's a tournament that we want to compete well in." - Rafael Nadal

"We're all very excited to be a part of this first ever event." - John Isner

WHAT'S THE FORMAT?

The 24 teams are split into six groups of four and will play three round-robin ties, consisting of two singles matches and one doubles contest. The singles ties will be best of three sets with tie-breaks, while the doubles will employ no-advantage scoring and a match tie-break rather than a third set.

All the group winners will make it through to the knockout phase, along with the best two runners-up, making it the Final Eight. 

WHAT'S THE PRIZE?

The not inconsiderable sum of $22million AUD (£11.6m) is up for grabs, along with up to 750 singles ranking points along the way.

WHO IS GOING TO WIN?

You will of course need to wait and see to get an answer to that one, but Spain are favourites as Nadal and Roberto Bautista Agut are in their ranks. Australia's home advantage could prove telling.