[pran]

 blackshoe, on 2012-November-02, 09:09, said:

Okay, fair enough I suppose. But there's no indication, other than it's the first one in the list, that arrow switching should be preferred to the other three. Are we supposed to take the list as "first in first out", and prefer the options in the order given? If so, how are we supposed to know that?

No, but an immediate arrow switch guarantees that a valid result will be obtained on this board.

All other options can result in an adjusted score becoming necessary, either because the Director cancelled the board right away or because he judges (after the play) that the exposure of the card may have affected the result.

[pran]

 sailoranch, on 2012-November-01, 21:10, said:

Because you usually don't arrow switch at teams.

You do (for cause) if you can arrow switch that same board in both rooms.

[bluejak]

 blackshoe, on 2012-November-01, 19:22, said:

Four options are given to the director. None of them is "cancel the board".

Law 16C2D: 'award an artificial adjusted score' means cancel the board.

 Vampyr, on 2012-November-01, 17:39, said:

Well, if it is a two-winner game then of course you cannot arrow-switch. Perhaps previous posters thought that went without saying.

I thought I made it clear in my answer that two-winner did not affect it. You can still arrow-switch.

 blackshoe, on 2012-November-01, 20:10, said:

Well, we could argue about "valid", but never mind that.

If arrow-switching is always best, why are the other options in the law?

Simple: because arrow-switching is not always best.

Redealing is a reasonable option when a board is being played for the first time at teams or pairs, though of course hand records affect this.

In a club when someone has seen a two I usually let them play it as is.

If two players have seen the queen then arrow-switching cannot help. Now you have to redeal: if not possible, let them play it if you think it hardly matters: if not possible, scrap the board.

There are four options for different situations.

 aguahombre, on 2012-November-01, 20:30, said:

Doesn't arrow-switching such as this in a straight Mitchell movement create a variable where the pairs are not playing this hand against the other pairs with which they will be compared at the end of the session?

Obviously. And if this was the final of the top World competition we might worry about it. But why on earth are we worrying in a club? You get a valid result on the board.

Oh, it's not perfect? Well, of course not: perfect unsullied results are only obtained at tables where there is no infraction. When an infraction occurs we follow the Laws plus commonsense. People like playing boards: do not cancel a board in a club unless there is a time problem or there is no viable alternative.

[sailoranch]

 blackshoe, on 2012-November-02, 09:09, said:

Okay, fair enough I suppose. But there's no indication, other than it's the first one in the list, that arrow switching should be preferred to the other three. Are we supposed to take the list as "first in first out", and prefer the options in the order given? If so, how are we supposed to know that?

I think it's just a matter of choosing the fairest, least disruptive option. Arrow switching means you're being compared to different players on this board, but at least the essential nature of the game is preserved. This will be a problem if the pros are seated in one direction and the rest of us in the other, but otherwise, this seems preferable to having to adjust or award average pluses.

I'm not denying that one pair might luck out and benefit from an arrow switch, but this could work out either way. Your expected score in matchpoints before you look at the cards would be roughly the same.