The Intesa Sanpaolo Next Gen ATP Finals has a round-robin format, with eight players divided into two groups of four. Seven players that qualify are determined by the ATP Race To Milan standings on the Monday following the Erste Bank Open in Vienna and the St Petersburg Open. The eighth player will be decided by a wild card. All singles matches are the best-of-five sets, with each set the first to four games (not six games).

Draw

The top-seeded player is placed in Group A and the second-seeded player is placed in Group B. Players seeded 3 and 4, 5 and 6, 7 and 8, are then drawn in pairs with the first drawn placed in Group A. Each player plays the three other players in his group. The winner of each group (best overall record) is placed in separate semi-final brackets, with the top player in Group A playing the runner-up in Group B, and vice versa. If two or more players are tied after the round-robin matches, the ties are broken by a tie-break procedure.

Semi-Final Qualifying Procedure

The final standings of each group shall be determined by the first of the following methods that apply:

a) Greatest number of wins.

b) Greatest number of matches played.
Comment: 2-1 won-loss record beats a 2-0 won-loss record; a 1-2 record beats a 1-0 record.

c) Head-to-head results if only two (2) players are tied.

d) If three (3) players are tied, then:
i) If three (3) players each have one (1) win, a player having played less than all three (3) matches is automatically eliminated and the player advancing to the single elimination competition is the winner of the matchup of the two (2) players tied with 1-2 records; or
ii) Highest percentage of sets won; or
iii) Highest percentage of games won; or
iv) The player positions on the most recent FedEx ATP Rankings.
v) If (i), (ii), (iii) or (iv) produce one (1) superior player (first place), or one (1) inferior player (third place), and the two (2) remaining players are tied, the tie between those two (2) players shall be broken by head-to-head record.

View more on page 71 of 2021 ATP Rulebook