Combinations, not a random draw
A round robin generator enumerates every unordered pair exactly once. For n participants, the number of matchups is n(n−1)/2. With Alpha, Bravo, Charlie, and Delta, that is 4×3/2 = 6 matches: AB, AC, AD, BC, BD, and CD. The result is deterministic once the roster is known; no probability is required to ensure coverage.
Checking four participants
The six expected meetings are Alpha–Bravo, Alpha–Charlie, Alpha–Delta, Bravo–Charlie, Bravo–Delta, and Charlie–Delta. Each participant appears in n−1 = 3 matches. Count those appearances as a quick audit: if Alpha appears only twice, a pair is missing; if Alpha meets Bravo twice, a duplicate has entered the schedule.
Growth is quadratic
Eight entrants create 8×7/2 = 28 matches, while twelve create 66. That growth matters for court time, volunteers, and travel. A page that lists every pairing does not choose dates, venues, rest periods, or home-and-away legs. Estimate the total session capacity before presenting the complete matchup list as an achievable calendar.
Coverage is not a bracket
Round robin play is useful when every competitor should meet every other competitor. It does not eliminate a loser, seed a knockout tournament, or rank ties without a scoring rule. Add points, tie-break criteria, and rounds separately. If the actual goal is four first-round matches from eight entrants, a bracket seeder has a different output and different assumptions.
Turn matchups into a usable season
After all pairs are listed, assign rounds so competitors have reasonable rest and a venue is not double-booked. A circle-method schedule can distribute opponents across rounds, while this page's pair list only proves coverage. For four participants, three rounds of two simultaneous matches can complete the six fixtures. Rainouts, home-and-away requirements, and unequal availability require a calendar policy layered on top of the combination count. With five entrants, add a bye placeholder: each round has two matches and one idle entrant, and five rounds are needed before every real pair has met.
Check that the venue can host the fixtures
Multiply the roster size by one less, divide by two, and make sure the available sessions can host that many fixtures.
Fixture-count questions
How many matches for five people?
Five times four divided by two equals ten unique pairings.
Does it choose a winner?
No. It only enumerates who meets whom; scoring and tie rules are separate.
Choose another competition format
All list tools · Secret Santa Generator · Tournament Bracket Seeder