Round robin schedule?

Question

Hello, I want to create a double round robin tournament which will have 20 teams participating. There are 2 rules I need to apply to this:

1. When each team has played an even amount of games, half are at home, and half away. 
2. A team can play 2 games home or away in a row, so long as rule 1 applies.

Thanks in advance :)

Duke · Accepted Answer

Use the schedule, suggested by Austrian chess master J. Berger:

http://en.wikipedia.org/wiki/Johann_Berger

Assign numbers to the teams (1, 2, ..., 20). Here are the rules:

1) Team #M (M < 20) plays against team #N (N < 20) in round #R, where

R = M + N - 1 if M + N ≤ 20, or

R = M + N - 20 if M + N > 20.

If M + N is odd, the lower number is home team, the higher - visiting team; if M + N is even, the higher number is home team, the lower - guest.

2)Team #20 (last numbered) plays against team #N (N = 1, 2, ..., 19) in round R, where

R = 2N - 1 if 2N ≤ 20, or R = 2N - 20 otherwise (2N > 20).

Team #20 is guest in its matches against ##1-10; it is home team against teams ##11-19.

For example study the complete schedule for 8 teams (home-guest) and you'll have no difficulty to compose what you need:

round 1: 1-8 2-7 3-6 4-5

round 2: 1-2 7-3 6-4 8-5

round 3: 3-1 5-6 4-7 2-8

round 4: 1-4 2-3 7-5 8-6

round 5: 5-1 4-2 6-7 3-8

round 6: 1-6 2-5 3-4 8-7

round 7: 7-1 6-2 5-3 4-8

The above applies if there are 7 (or other odd number) teams, team #8 is fictitious, what means that every other team has a free round.

P.S. I didn't pay attention that you want a DOUBLE round robin schedule. Just repeat the same schedule once more with the hosting rule reversed.

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Round robin schedule?

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