[TomCowley]

You know how to calculate the number of bets for each number of teams, like 6c3 = 20. To figure out how many bets are still live after one team loses, just do the calculation for n-1. So if you have 6 teams round-robined in 3s, for 20 games, once one loses, do 5c3=10. So you have 10 live bets and 20-10 lost bets. Once another team loses, do 4c3=4, so the second loss costs you 6 more bets. Repeat for each set (2-teamers, 3-teamers, etc.)

FWIW, you're better off putting all of your money into the 2/3 teamers (whichever has better odds, +100/+180 play the 2-teamers, -110/+180 play the 3-teamers) and ignoring the 4-5 teamers. An additional small play on the 6-teamer is fine if the 6-teamer has equivalent odds to the other group you're playing.