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18 or 19 tables Help please!

#21 User is offline   Pig Trader 

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Posted 2017-December-10, 15:06

The Appendix Mitchells also have all pairs playing all 26 boards.

If we ever had 21, 23 or 25 tables again, we'd still stick with the Appendix Mitchell as we only need two sets of duplimated boards. I think that's the only disadvantage of the Web Mitchells over Appendix Mitchells.
Barrie Partridge, England
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#22 User is offline   lamford 

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Posted 2017-December-10, 16:34

View Postweejonnie, on 2017-December-10, 13:59, said:

I don't understand that - you can play a 20 table Mitchell with 40 boards (skip after round 10, 2 rounds arrowswitched if you want a single winner). Of course you would have to play 14 rounds to qualify under the 70% rule.

I might be talking rubbish here, but I was thinking of having 32 boards pre-duplicated, plus another set of virgin 24 boards. Say there are 20 tables. Round 1 starts with 1-20 and boards are shared so you have everyone having played 2 boards from 1-20. 1-2, 1-2, 3-4, 3-4 etc. Tables 1-8, the first four to finish, now duplicate another set of boards 1-8, the ones they have after round 2, so there are 40 boards in play, two copies of 1-8 and one copy of 9-32. The 20 NS players play 24 of the 32 boards and do not need to board share thereafter. The EW players will also play 24 of the 32 boards. It seems to me

a) that you only need to bring one set of 32 boards, plus a spare set of boards
b) that you only need to duplicate 8 more boards for 20 tables after round 1
c) that you will not have board sharing after round 1
d) that the earlier to finish of each pair of the lower numbered tables can duplicate the boards. Except only SB will be able to duplicate the board he played ten minutes earlier from memory.

I seem to have done a spreadsheet for 20 tables with 40 boards of which there are only 32 different. You need 12 rounds for 70% of the boards to be played. For example, NS 1 plays boards 1-24 in order, NS 5 plays 5-28 in order, NS 9 plays 9-32 in order, NS 13 plays 13-32 and then 1-4 and NS 17 plays 17-32 and then 1-8. So boards 1-8 are played more times. EW 1 plays 1-2, 5-6, 9-10, 13-14, 17-18, 21-22, 25-26, 29-30, 3-4, 7-8, 11-12, 15-16. EW 11 plays 11-12, 15-16, 19-20, 23-24, 27-28, 31-32, 3-4, 7-8, 13-14, 17-18, 21-22, 25-26. I think the skip comes after 8 rounds.

Feel free to demolish the above!

It just occurred to me that the above can be improved significantly by having the duplimate machine make board 33 the same as board 1, board 34 the same as board 2 etc. Then there is no need for any duplication at the table, and no need for board sharing. You just bring 40 pre-duplicated boards, of which 8 are the same. Or you can have the hopper ready to double duplicate as many extra boards as you need as soon as the number of players are known.
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#23 User is offline   weejonnie 

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Posted 2017-December-11, 12:03

Not sure how this works, obviously easier on a spreadsheet

The first round - you have 10 pairs of tables sharing
Is that 1 shares with 2, 3 with 4 etc or 1 shares with 17, 2 with 18 etc

1: 1-2
2: 1-2
3: 3-4
4: 3-4
....
19: 19-20
20: 19-20


And where do boards 21 - 32 feed in?
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#24 User is offline   lamford 

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Posted 2017-December-11, 18:52

View Postweejonnie, on 2017-December-11, 12:03, said:

Not sure how this works, obviously easier on a spreadsheet

The first round - you have 10 pairs of tables sharing
Is that 1 shares with 2, 3 with 4 etc or 1 shares with 17, 2 with 18 etc

1: 1-2
2: 1-2
3: 3-4
4: 3-4
....
19: 19-20
20: 19-20


And where do boards 21 - 32 feed in?

If boards 1-8 are pre-duplicated twice for 20 tables, then one can have 1-2 on table 1 and also on table 17 in round 1, and then it doesn't require sharing. My original version had 1-20 in play in round 1, and then 21-32 feeding in in round 2.

However, there is a simpler solution still, and the attached spreadsheet has the following features:

a) If 32 boards are duplicated and 1-8 are doubly duplicated, we can have 20 tables without board sharing in rounds 1-10. For rounds 11 and 12 board sharing is needed, or the additional boards can be duplicated during the evening by the TD.

b) The skip is after 5 rounds but there is no need for a bystand or pivot.

c) One can add a 13th or 14th round very easily if time permits. Boards should be checked in rounds 11 and 12 as the board movement is slightly irregular.

And thanks to ChrisM and Barrie for some help!

https://www.dropbox....oards.xlsx?dl=0
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