round robins are a series of two-teamers, in a three team round robin there are 3 two team parlays, a-b, b-c, and a-c. there are even larger round robins with 4 teams you have 6 combinations, 5 teams 10 combinations and so on.
I never do more than 4 generally.... Teams a,b,c, and d.
And I choose to use only 3 and 4s meaning 4, 3 team parlays using each of those teams at x amount of dollars and 1, 4 team parlay.... If you win 3 of the 4, you will make a little bit of money.... 4 of 4 and you hit 5 parlays!!! 4 3 teamers at 6:1 and one at 11:1!