After the success of the inaugural Next Gen ATP Finals last year in Milan, the tournament went a few steps farther for this edition. Many of the rules are wildly different from what fans have seen on the rest of tour, such as no line judges calling the shots (Hawk-Eye Live will be entirely used to check if balls are out).
With all of the new changes, keeping track of them can be confusing. First, get a recap of the rules from the stars themselves then come back and see how much you know about the latest rules.