8 golfers - rota system? maths query

[jusme]

8 of us play together on a Saturday (2x4 balls) and as it stands balls are thrown in the air and 4 balls chosen from that. Given the process obviously people can end up playing with the same people or rarely with others on lots of occasions.

Goal - to use such a mathematical program where it changes every week and over time everyone is playing with others/different 4 balls as often as possible.

Anyone know a simple way/rota of arranging such a thing. An algorithm type thing??

 

[User101]

Are you being serious ?

Just play the game, balls in the air seems to have worked for centuries.

 

[PhilTheFragger]

Moving to the lounge

 

[rosecott]

8 of us play together on a Saturday (2x4 balls) and as it stands balls are thrown in the air and 4 balls chosen from that. Given the process obviously people can end up playing with the same people or rarely with others on lots of occasions.

Goal - to use such a mathematical program where it changes every week and over time everyone is playing with others/different 4 balls as often as possible.

Anyone know a simple way/rota of arranging such a thing. An algorithm type thing??

12 of us go to Belek every year and play 4 rounds. For the last 6 years I have offered a £10k prize for anyone who can come up with draws for the 4 rounds which ensures that everyone plays with every other player.

 

[tsped83]

Really? Balls out of hat is as random as you can get. There must be better things you can do with your time...

 

[jusme]

12 of us go to Belek every year and play 4 rounds. For the last 6 years I have offered a £10k prize for anyone who can come up with draws for the 4 rounds which ensures that everyone plays with every other player.

Be careful there - you just might have to pay out that prize

Sadly I am serious, given that there is one or two in the eight that some people are less pleased with playing with. Often it appears, the same people are playing with them, so I was looking for a less random and more equitable system.

I appear to have found (in another thread) the best answer - a company who came up with a computer program to do this very thing. Golf genius pairings. Go to website - click golf trips (bottom of the page) and then click for free pairings. I picked 8 players - 24 weeks (as this was the longest amount of weeks) and they emailed me back within the hour with a spreadsheet - absolutely excellent. Works out that everyone plays with 6 of the others 10 times and the 7th 12 times. I'm sure there is an exact number of players/weeks combo that it could work out totally equal, but I will not bother the person inputting the data to find this.

Try out your combo to see what you get back

 

[SwingsitlikeHogan]

Be careful there - you just might have to pay out that prize

Sadly I am serious, given that there is one or two in the eight that some people are less pleased with playing with. Often it appears, the same people are playing with them, so I was looking for a less random and more equitable system.

I appear to have found (in another thread) the best answer - a company who came up with a computer program to do this very thing. Golf genius pairings. Go to website - click golf trips (bottom of the page) and then click for free pairings. I picked 8 players - 24 weeks (as this was the longest amount of weeks) and they emailed me back within the hour with a spreadsheet - absolutely excellent. Works out that everyone plays with 6 of the others 10 times and the 7th 12 times. I'm sure there is an exact number of players/weeks combo that it could work out totally equal, but I will not bother the person inputting the data to find this.

Try out your combo to see what you get back

I think this is just fairly simple statistical stuff (though stats was not my favourite topic in my Maths Degree) - combinations and permutations. So write down all combinations of Four from Eight (if I recall in 'permutations' the order of the four matters - and obs for a golf four ball it doesn't - so we're talking 'combinations'). Then just random select from all possible combinations - and then drop the one chosen for the next time.

 

[Deleted member 23270]

Blimey this isn't exactly rocket science!

Number all players from 1 through to 8.

Week 1 numbers 1-4 play together and 5-8 play together
Week 2 numbers 2-5 play and 6-8 +1
Week 3 numbers 3-6 play and 7,8,1,2

Repeat each week. Why make it any more complex??

 

[SwingsitlikeHogan]

Blimey this isn't exactly rocket science!

Number all players from 1 through to 8.

Week 1 numbers 1-4 play together and 5-8 play together
Week 2 numbers 2-5 play and 6-8 +1
Week 3 numbers 3-6 play and 7,8,1,2

Repeat each week. Why make it any more complex??

Which is true - or just write down every combination of four from eight - stick them in a hat and each week draw one out of the hat - then chuck it away.

 

[need_my_wedge]

Only 8 of us travel every year. We play as a pair with your room mate, then play each round against one of the other three rooms. That way everyone has played with everyone else at least once, whilst obviously playing with your room mate each time. Works for us.

 

[Orikoru]

How about every last round of the month you don't leave it to chance, and just pair anyone up who hasn't played together that month? Then go back to random draws for the new month.

 

[TreeSeeker]

This is a pretty interesting puzzle, but being lazy i would always take the solution i know of which is the closest fit.

I would "borrow" the starting positions and movements calculated for Bridge individual tournaments, since they work to rotate people through evenly, most movements are for a larger number of rounds than you would play golf for but by being selective on the rounds you play it should work out nicely, however you like it.

For 3 groups of 4 from 12 players something like

Group 1	Group 2	Group 3
Team 1	Team 2	Team 1	Team 2	Team 1	Team 2
12	1	5	10	7	11	8	9	2	4	3	6
12	2	6	11	8	1	9	10	3	5	4	7
12	3	7	1	9	2	10	11	4	6	5	8
12	4	8	2	10	3	11	1	5	7	6	9
12	5	9	3	11	4	1	2	6	8	7	10
12	6	10	4	1	5	2	3	7	9	8	11
12	7	11	5	2	6	3	4	8	10	9	1
12	8	1	6	3	7	4	5	9	11	10	2
12	9	2	7	4	8	5	6	10	1	11	3
12	10	3	8	5	9	6	7	11	2	1	4
12	11	4	9	6	10	7	8	1	3	2	5

For 2 groups of 4 from 8 players

Group 1	Group 2
Team 1	Team 2	Team 1	Team 2
8	1	6	2	5	7	3	4
8	2	7	3	6	1	4	5
8	3	1	4	7	2	5	6
8	4	2	5	1	3	6	7
8	5	3	6	2	4	7	1
8	6	4	7	3	5	1	2
8	7	5	1	4	6	2	3

Obviously there are going to be mathematically better solutions out there (given these are worked out to avoid people playing the same cards twice as a complicating factor) but these would do for me.

 

[Orikoru]

I thought about a system but it has be very long-winded to avoid some playing with the same other person 4 weeks out of 5 and things like that.

I suggest you just use this: https://www.random.org/lists/ Put everyone's names in and hit randomise. Top 4 are one group, next 4 are the other group. It should be truly random so everyone will surely play with everyone eventually.

 

[TheDiablo]

Blimey this isn't exactly rocket science!

Number all players from 1 through to 8.

Week 1 numbers 1-4 play together and 5-8 play together
Week 2 numbers 2-5 play and 6-8 +1
Week 3 numbers 3-6 play and 7,8,1,2

Repeat each week. Why make it any more complex??

LOL, it might not be rocket science but your 'solution' is actually worse than random. As an example, Player 3 and player 4 play every game together, yet player 1 only plays with 4 once.

 

[Orikoru]

LOL, it might not be rocket science but your 'solution' is actually worse than random. As an example, Player 3 and player 4 play every game together, yet player 1 only plays with 4 once.

1 and 5 are complete strangers as well.
Edit: So are 3 and 8.

 

[drdel]

If you want to use a computer/spreadsheet enter (or generate) the combinations in the spreadsheet then use the 'search facility to identify any matching combinations and delete them all bar one

 

[jusme]

Thanks for all the suggestions, but as some of you have yet to see, it isn't as easy as you and many others, including myself at one point thought.

No further need for suggestions as if you look back at my second post on page one you will see a solution that works has been found. A company has devised a program to achieve the best results with any numbers of players and games. Have a look at the online reviews and you will see it's success - its free to try - read my post and put your own numbers into the program to see. See post 6 for the appropriate site

 

[jusme]

Are you being serious ?

Just play the game, balls in the air seems to have worked for centuries.

Oddly enough yes, hence I asked the question, or was your question not meant as a question?

 

[jusme]

Really? Balls out of hat is as random as you can get. There must be better things you can do with your time...

Yes really. I don't want random as random can be repetitive. I appreciate your concern for my time

 

[Deleted member 23270]

As an example, Player 3 and player 4 play every game together, yet player 1 only plays with 4 once.

Are you sure?