Originally posted on 08/28/2016:
Easiest way is take the number of plays and subtract 1 since you can't parlay a team with itself. Take that number and divide by 2. Take that number and multiply it with the total play number.
so your example would be:
27-1 = 26/2 = 13 and 13*27 = 351
11 team example:
11-1 = 10/2 =5 and 5*11 = 55