[Vampyr]

I recently played the inaugural game of my local Bridge club. There was no arrow-switch, But the results seemed to mash the N/S and E/W lines together. If we are playing a two-winner movement, the results obviously have to be consistent with that. Please advise how to disable the one-winner results as it seems, bizarrely, to be the default.

[McBruce]

Vampyr, on 2020-May-05, 15:35, said:

I recently played the inaugural game of my local Bridge club. There was no arrow-switch, But the results seemed to mash the N/S and E/W lines together. If we are playing a two-winner movement, the results obviously have to be consistent with that. Please advise how to disable the one-winner results as it seems, bizarrely, to be the default.

The BBO one-winner movement is a Howell variant I call the volleyball movement*. NS#1 stays, other NS pair go up while EW pairs go down, highest NS becomes highest EW next, EW1 becomes NS2. Works with all tables playing the same boards at the same time, but may not be as scrupulously fair as arrow switches. Plus, with 10-15 tables (16+ splits into sections) there are several pairs that will never switch directions. That may be what happened in your game. It is a one winner game since all N-S and all E-W are not completely separated.

*I call it the volleyball movement because in highschool gym class we split into six teams and played a complete round-robin this way. One team stays, others rotate.

[Vampyr]

McBruce, on 2020-May-05, 16:04, said:

The BBO one-winner movement is a Howell variant I call the volleyball movement*. NS#1 stays, other NS pair go up while EW pairs go down, highest NS becomes highest EW next, EW1 becomes NS2. Works with all tables playing the same boards at the same time, but may not be as scrupulously fair as arrow switches. Plus, with 10-15 tables (16+ splits into sections) there are several pairs that will never switch directions. That may be what happened in your game. It is a one winner game since all N-S and all E-W are not completely separated.

*I call it the volleyball movement because in highschool gym class we split into six teams and played a complete round-robin this way. One team stays, others rotate.

No, it was a Mitchell with the lines separated.

[barmar]

I implemented the EBU points several years ago, and I think they told me to award them based on overall rank, not rank within section/direction.

Perhaps I misunderstood. I'll ask Gordon to comment.

[Vampyr]

Yes, guidance from Gordon would be helpful. I assume that when he or his representative asked for one-winner movements they assumed that that would include an arrow-switch and thought it obvious enough not to have to mention it.

[gordontd]

Vampyr, on 2020-May-06, 18:55, said:

Yes, guidance from Gordon would be helpful. I assume that when he or his representative asked for one-winner movements they assumed that that would include an arrow-switch and thought it obvious enough not to have to mention it.

Hi Stefanie,

There is a limited range of movements available, but you will see that the results from your game are shown both ways, as a single ranking list and as separate NS and EW lists. The results can, and should, be submitted for master points based on a two-winner result, so those shown in the BBO ranking should be taken as approximate only.

When we first re-started our games seven weeks ago, we didn't have a method to extract all the data and so we were happy to do what was straight-forward with what we had and gave master points based on the single field list that we received automatically. This goes back to when we used to run small "Swiss" games about seven years ago, which were indeed one-winner movements.

The overall number of master points issued by the two methods is similar and any differences would have been small. As our games got larger our "theoretical top" formula kicked in and the size of top award was reduced appropriately. We now do have a method to extract all the data and are awarding master points separately for the two lines (but overall, not within sections). We have a note to this effect on our website.

[Vampyr]

Thanks Gordon.

Do you have any idea how much of the entry fee actually goes to the EBU in the EBU games and the clubs in their games?