NUMBER OF ROUND ROBIN MATCHES

I did this for table tennis tournaments but, of course, it applies for almost anything. This assumes each player or team plays each of the others in the round robin once. You can then advance to the next round the winner, or 2, or more.

To play safe, figure 30 minutes per table tennis match, best of 5 games; 45 minutes best of 7. Ex: 4 person RR, best of 5, 1 table, takes about 3 hours. In reality; it will probably finish in plus/minus 2.5 hours.

# of players in rr matchups = total matches needed to play  (n X (n=1)/2 =

2 AB = 1 match

3 AB, AC, BC = 3 matches

4 AB, AC, AD, BC, BD, CD = 6 matches

5 AB, AC, AD, AE, BC, BD, BE, CD, CE, DE = 10 matches

6 AB, AC, AD, AE, AF, BC, BD, BE, BF, CD, CE, CF, DE, DF, EF = 15 matches

7 AB, AC, AD, AE, AF, AG, BC, BD, BE, BF, BG, CD, CE, CF, CG, DE, DF, DG, EF, EG, FG = 21 matches

8 AB, AC, AD, AE, AF, AG, AH, BC, BD, BE, BF, BG, BH, CD, CE, CF, CG, CH, DE, DF, DG, DH, EF, EG, EH, FG, FH, GH = 28 matches

9  ( ) = 36 matches

10  ( ) = 45 matches

11  (  ) = 55 matches

12  (  ) = 66 matches

13  (  ) = 78 matches

14  (  ) = 91 matches