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51

Requests / Re: Bjerring tournament templates

« Last post by Ian Wakeling on July 06, 2025, 09:43:16 AM »

Hi, I think if you have exactly the right number of players and number of rounds, then there may be a perfect tournament, but most of the time, with other numbers of players and rounds the only thing possible will be a long way from perfect.  How far away from perfect probably depends on the search algorithm used, and this makes it difficult to know if you you have found an optimal solution.  I don't currently have an software that might help here, but I will think about some options.

Here is one perfect solution for 12 players in 11 rounds - where each player partners with each other player 5 times and opposes each other player 6 times.

 P1 P2 P3 P4 P5 P6    P1 P2 P3 P4 P5 P6
( 3 12  9 11  5  1) v ( 4  6 10  7  8  2)
(12 10  3  9  7  4) v ( 1 11  5  8  2  6)
( 8  7 12  6  3  5) v (11  2  4  9 10  1)
( 3 11  8  2  4 12) v (10  5  1  7  6  9)
(11 10  7  5 12  2) v ( 8  1  9  6  4  3)
( 7  6  4  1 11 12) v ( 2  9  5  8  3 10)
(10  9  6 12 11  8) v ( 1  2  3  4  5  7)
( 6  1 12  3  2 10) v ( 5  4  7 11  9  8)
( 9  8  2 12  1  7) v ( 4  3 11  5 10  6)
( 5 12  1 10  8  4) v ( 2  7  6  3  9 11)
(12  5  2  4  6  9) v ( 7  3  8 10  1 11)

If P1 to P6 are 6 positions, then each player appears twice in 5 positions, and once in the other  position.

Is 11 rounds something that is practical?  I guess another perfect schedule might be possible for 13 players and 13 rounds, with each player having one bye.

52

Requests / Bjerring tournament templates

« Last post by cvvcdad on July 05, 2025, 08:30:19 PM »

Hi! The help given here is amazingly valuable! If you can help with this, it will be greatly appreciated by many, many volleyball coaches.

I often run Bjerring tournaments during practice, and also for school vb tryouts. It's not really a problem to define Bjerring tournaments for the number of players at practices. But tryouts are a completely different animal.

In general, what I need is the teams for each round of a 6v6 Bjerring tournament for n players. A Bjerring tournament is player-defined instead of team-defined, so the mixing from round to round is in terms of which players are playing together and which players are they playing against, and NOT which teams are playing each other in a particular round. There are no defined teams, just two sets of 6 players each game.

An ideal Bjerring tournament has any given player playing with every other player the same number of games and playing against every other player the same number of games. I assume that isn't possible for every value of n; if not a variance of 1 from player to player would be fine.

A quick example: the first game of a Bjerring tournament has players 1/2/3/4/5/6 vs players 7/8/9/10/11/12; the second game is players 1/3/5/7/9/11 vs players 2/4/6/8/10/12; etc. When the tournament is over, player 1 will have played x times with every other player, and z times against every other player. Again, this is the PERFECT Bjerring tournament, but a slightly-less-than-perfect format would work too.

What would be amazingly valuable is a tool that allows a coach to input the number of players, with the output being the player assignments for each game of 6v6 for the number of rounds needed. What would be even more valuable would be a tool that does this while allowing for various-sized games -- e.g., a tournament of all 6v6 games, a tournament of all 5v5 games, etc.

I know that's a LOT to ask; alternatively (and this might be a lot to ask too), tables defining 6v6 games for Bjerring tournaments for 12 players, 13 players, etc. up to 24 players would be great! I would likely never bother you again!

Thanks so much in advance for any help you can give to all of us vb coaches out here!

53

Requests / Re: Am I asking for the impossible?

« Last post by Mike Von on June 24, 2025, 09:50:56 AM »

Ian,

You are amazing!



Thank you very much, our little tournament will run smoothly now.

Mike

54

Requests / Re: Am I asking for the impossible?

« Last post by Ian Wakeling on June 24, 2025, 03:38:46 AM »

Here are some possibilities for your 8 round schedule - the 16 player one is best since everyone has the same number of games.


13 players (players 1 to 5 play in every round, the others each have one bye)

( 5 12 v  7  8)  (11  4 v 10  6)  ( 3  9 v  1  2)
( 9  5 v 13 10)  ( 8  4 v 11  1)  ( 2  3 v  7  6)
(12  3 v  2  9)  ( 7 13 v  1  4)  ( 5  6 v  8 10)
( 5  2 v  9 11)  (13  6 v  1  7)  ( 8 12 v  3  4)
( 1 12 v 11 10)  ( 8  6 v 13  3)  ( 4  2 v  7  5)
(11  2 v  4 13)  ( 9 10 v  3  7)  ( 1  5 v  6 12)
( 5  3 v 11 13)  (10  2 v  1  8)  ( 4  6 v  9 12)
( 1  3 v  5  4)  ( 7  9 v 11  8)  (13  2 v 12 10)

14 players (players 13 & 14 have 6 games, the others have 7 games)

( 8 12 v 11  3)  ( 7  1 v  5  2)  ( 6  9 v  4 10)
( 2  3 v 10  5)  ( 6  8 v 14 13)  ( 1  9 v  7  4)
(12  3 v  6  7)  ( 2 14 v 11  4)  (13  8 v  5  1)
(11 12 v  1 10)  (14  4 v  5  3)  ( 9 13 v  2  6)
( 1 11 v  9  3)  (10  7 v  8 14)  (13  2 v 12  4)
( 1  2 v  6 14)  ( 9  8 v  7 12)  (11  5 v 10 13)
(12  9 v  5 14)  (13  7 v 10  3)  ( 4  6 v 11  8)
( 9  2 v  8  3)  ( 6 11 v  7  5)  (12 10 v  4  1)

15 players (players 1-9 have 6 games, players 10-15 have 7 games)

(13  5 v  7 12)  (10  8 v 11 15)  ( 4  6 v  9 14)
(15  1 v 12 14)  ( 3  8 v 10 13)  ( 2 11 v  7  9)
(11  1 v  2 15)  (12  6 v  4 10)  (14  5 v  3 13)
(15 13 v  6  2)  ( 5  3 v  1  9)  (14  4 v  8  7)
( 1 12 v  9  8)  ( 5  4 v 10  2)  ( 3  6 v  7 11)
( 5 12 v  6 11)  ( 9 13 v 10 15)  ( 8  2 v  3 14)
(11  9 v 14 13)  ( 4 12 v  3 15)  ( 6 10 v  1  7)
( 5  7 v  8 15)  ( 1  4 v 11 13)  (14  2 v 10 12)

16 players (all players have 6 games)

(15 12 v 16  8)  ( 6  5 v 14  9)  ( 7 11 v 13 10)
( 9 11 v 12  2)  (16 10 v 14  4)  ( 1  3 v 13 15)
(14  3 v  1  8)  (15  4 v  7  6)  ( 2 16 v  5 13)
( 2  6 v  3 10)  ( 1 11 v  9  4)  ( 8 12 v  5  7)
( 6 16 v 11  8)  (12  3 v 10  4)  (14  2 v  7 15)
(13  4 v  5  8)  ( 7  3 v  9 16)  (11 12 v  1 15)
( 1 10 v 16  5)  ( 6 14 v 13 12)  ( 2  9 v  4  8)
(13  9 v 15 10)  ( 7  2 v  1  6)  ( 5 14 v 11  3)


Hope that helps,

Ian

55

Requests / Re: Am I asking for the impossible?

« Last post by Mike Von on June 20, 2025, 03:32:07 PM »

Ian,

I searched the site but couldn't find:

doubles tennis, changing partners and opponents every round
3 courts
8 rounds
player numbers can be 13, 14, 15, 16
play with a player a maximum of one time
minimize the number of times you play against any player

Are there any solutions that meets these requirements?

Any help is much appreciated.

56

Requests / Re: Newbe

« Last post by Ian Wakeling on May 26, 2025, 03:39:29 AM »

Here is a schedule for 16 teams A to P playing 5 rounds per night for 4 weeks.  Each team has either 3 or 4 games per night and plays either 2 or 3 times at each pit (the 6 columns).


(C E) (B K) (H P) (M O) (I L) (A D)
(K O) (D L) (A F) (G I) (J N) (B C)
(A L) (H I) (C F) (G P) (B N) (E M)
(I K) (O P) (H N) (D J) (E F) (G L)
(D F) (G H) (B J) (A E) (K M) (C P)
------------------------------------
(G J) (C L) (B O) (E N) (A I) (M P)
(D N) (F M) (G K) (H L) (C J) (B I)
(F N) (E P) (I O) (A M) (D K) (C H)
(K P) (D G) (L M) (B H) (E O) (F J)
(N P) (C O) (E G) (K L) (A H) (I J)
------------------------------------
(B M) (A K) (E L) (F I) (D P) (N O)
(E H) (J M) (K N) (C G) (B L) (D O)
(F G) (A B) (D M) (C K) (H J) (I P)
(L P) (E I) (F H) (M N) (A O) (J K)
(B E) (D H) (J O) (A C) (F P) (G N)
------------------------------------
(H O) (B F) (J L) (D I) (C M) (A G)
(H M) (A N) (D E) (B P) (F K) (L O)
(C D) (J P) (I N) (F O) (G M) (E K)
(A J) (G O) (C I) (B D) (L N) (H K)
(I M) (C N) (A P) (E J) (B G) (F L)

57

Requests / Re: Newbe

« Last post by Morti on May 24, 2025, 05:24:17 PM »

Thanks Ian.
  For this year we are only 16 teams with the 6 pits available.
  We usually like to play 5 to 6 games each Monday night.
  Again rotating through the pits available soo as no team plays on the same pit for every match. 

58

Requests / Casino games night - 7 tables, 28 players

« Last post by sjaksloss on May 19, 2025, 12:17:21 PM »

Hi,

I am going to organize a casino games night with 7 games (tables) and 28 players. So 4 players at each table.
Each player will have to play each game only once, which means there should be 7 rounds in total.

What I also want, is try to avoid having the same people playing against each other at other tables. So besides changing tables, opponents should also change as much as possible.


I've had a look at the whist schedule, but in that schedule players end up at the same table multiple times.

I have absolutely no idea if what I want is possible, but would appreciate it if you could have a look at it 

Thanks!

59

Requests / Re: 48 team event

« Last post by Ian Wakeling on May 15, 2025, 03:29:19 AM »

Hi,

An interesting problem.  If each team must play each event exactly once, then there are only two possibilities.

(a) 3 teams per event with 16 events and 16 rounds.
(b) 4 teams per event with 12 events and 12 rounds.

Both of these can be found in the Foursome-Tournaments Excel file that can be found in this thread.  You need to be logged in to see the attachment.  For (b) you can use the 48 players worksheet, for (a) use the 64 players worksheet after deleting the last column of each foursome containing the players B17-B32.  If you wish you can organize the teams into 3 groups (option a), or 4 groups (option b).

60

Requests / 48 team event

« Last post by Marquel1989 on May 07, 2025, 01:17:39 AM »

Trying to schedule a 48 team schedule. 

Want all 48 teams competing at the same time. And I want 3 or 4 teams competing per event (whichever works better) 

I am flexible with the number of events/rounds (e.g 10 11, 12 or whatever works best), but each team should play each event just once. 

However, trying to minimize the amount of times that the same teams play against each other. (Each team is not required to play every team, but don’t want any team to play another team more than once, if possible).