Breaking down the ins and outs of the new ATP Cup

With "Cup" discourse in recent years dominated by the revamped Davis Cup and smash-hit Laver Cup, a lot tennis fans find themselves asking: What in the world is this ATP Cup I keep hearing about?

The short answer is the it's a little like the Hopman Cup from years past, but with only ATP players, and expanded to 24 teams competing in three Australian cities—with 750 ranking points line.

Here are some things to know before this all-new tournament kicks off the 2020 season:

Who: Nineteen teams have already been accepted (the rest will be determined on Nov. 13), and the entries include all of the top players—yes, that means Roger Federer, Rafael Nadal, Novak Djokovic and Andy Murray. The United States is set to be represented by John Isner and Taylor Fritz so far, though up to five players are allowed on the final team.

Here is the full list of entrants to date.

What: The 24 countries will contest a World Cup–style tournament consisting of a round-robin and knockout stage. The USA has been drawn into Group D, to face Daniil Medvedev's Russia, Fabio Fognini's Italy and one team still to qualify.

The matches themselves will be reminiscent of the Hopman Cup: Two singles and one doubles match are played to determine the winner of the two-out-of-three tie. Singles will be best of three sets, and doubles will use the same super-tiebreak format it has on tour.

Where: The group stage will be played in three different cities in Australia. Some notable placements: Djokovic's Group A in Brisbane, Nadal's Group B in Perth and Federer's Group C in Sydney. The United States, too, will start in Perth. The knockout rounds will all take place in Sydney.

When: The 2020 ATP Cup will run for 10 days, Jan. 3–12.

Tennis has definitely entered a new and untested part of the calendar. Before another Grand Slam is played, the sport will see the third edition of the Laver Cup, the inaugural playing of the radically reformed Davis Cup (to which this tournament looks awfully similar) and the first-ever ATP Cup.

Considering the success of the Laver Cup, team competitions appear to be the obvious next frontier for capturing the audience's consciousness. The question is: Can that excitement be replicated? The ATP Cup sure seems to be giving it a good shot.