Sailing Champions League Round Robin

[skyywalker]

Hi there,

first of all, new forum looks great and thank you for all the work going into this !

Now to my current task: I am running a sailing champion of champions event with 18 entries. Every race has 6 boats in it (1 "flight" consists of 3 races, so that every boat has sailed one race).

In the end, every boat must have sailed against every other boat, ideally the same number of times.

So the first flight looks like this:
Race 1: 1 2 3 4 5 6
Race 2: 7 8 9 10 11 12
Race 3: 13 14 15 16 17 18

How do I create a fair round robin for that ?

Thanks for your help ?

Cheers,
Markus

[Ian Wakeling]

Hi Markus,

Welcome back!

Regarding the 18 boats, I am worried that this may not be possible as the number of flights required will be too high.  My initial checks suggest that you will need either 5 or 6 flights just to make sure that every boat has sailed against every other at least once.  The ideal solution that you are looking for would require 17 flights.  How many flights can you manage to run?

Best,

Ian

[skyywalker]

Hi Ian,

(have to figure out how to get notifications for new post  )

we have time for around 40 races regardless of the number of flights they are organized in. We can adjust a bit upward/downward as we have some flexibility in the schedule. 17 flights would be 51 races... I will see if I can squeeze some more time out but it would be a good start if you have a schedule for that.  As it is a wind powered sport people are used to not completing the round robin, but what I have seen in other competitions so far didnt look very balanced so I am looking for advice here as this forum is amazing for all of this !

Cheers,
Markus

[Ian Wakeling]

Hi Markus,
Here is the ideal solution with 17 flights, where each boat will sail with every other boat exactly 5 times.  The schedule is also arranged such that boats appear either 2 or 3 times in each of the 6 columns.  If that is too much, would it be possible to have 9 boats per race, then you would only need a total of 34 races for an ideal solution.
It seems the new message board renders tables as images, so I have attached an Excel file for you to download the schedule (you must be logged in to see the download link).
Best regards,
Ian




PS When you are posting a message there should be a drop down list called "Attachments and other options". If you click on this the it should reveal the "Notify me of replies" button.

[skyywalker]

Hi Ian,

thats great - I think even if we would not complete the full schedule it will be fair racing for everyone (often enough against each other) to qualify boats to the final.

If you wouldnt mind posting the 9-boat per race solution in case I can find enough boats (as we need to provide them and swap between the teams) ? It gets a bit messy with 9 in a race but it is worth a thought.

Thanks again,
Markus

[Ian Wakeling]

Markus,

Unfortunately I wrote the comment about 9-boat races without checking first.  The 34 race schedule does not exist, so you would need 68 races for the ideal balance which is clearly too much.

Ian

[skyywalker]

Hi Ian,

many thanks - I will try to squeeze some more time out and make the 51 race schedule work. Event is late this year, just wanted to get prepared in time... thanks a lot for this !

Cheers,
Markus