# Combinatorics question - 10 teams

• Jul 17th 2013, 12:01 PM
PITKES1
Combinatorics question - 10 teams
Hi i want to ask you if you could help with this problem :

I have 10 teams and 9 days... each day one team must play one match with another team (not same as already played before/diferent team).
How will look table of matches ? I mean can you write each day which teams will play together ?

I tried many ways but i got bored of thinking :D ... i cant solve it, so if you can please help me its important for me.
Thanks
• Jul 18th 2013, 12:25 AM
chiro
Re: Combinatorics question - 10 teams
This is a link I posted in an earlier thread that talks about the relationship between the correlation coefficient and binary random variables:

Journal of Statistics Education, V5N3: Falk

Hopefully you can use this to extract the probability.
• Jul 18th 2013, 04:23 AM
BobP
Re: Combinatorics question - 10 teams
Movements more general than this are used in Bridge tournaments, they are known as Howell movements.

As well as pairs (" teams ") moving around there are also sets of boards moving around. The requirement is that every pair plays a set of boards against every other pair with the stipulation that no pair plays the same set of boards twice.

Numbering your teams 1 to 10, a schedule for the movement of the teams could be :

Day 1 2 v 4 8 v 7 10 v 1 6 v 3 9 v 5
Day 2 3 v 5 9 v 8 10 v 2 7 v 4 1 v 6
Day 3 4 v 6 1 v 9 10 v 3 8 v 5 2 v 7

etc., follow the obvious pattern.
• Jul 22nd 2013, 06:02 AM
PITKES1
Re: Combinatorics question - 10 teams
thanks BobP , you saved my time :D thansk a lot ;)