After a recent experience of being surprised how a passed in hand was scored, I thought I would share it with you. I naively had the idea that more or less the two pairs would get the same (middling) score but that is not quite how it works.
In normal duplicate, after a board is played there is a score - eg +80 for the pair making 1S and -80 for their opponents. At the end, all the EW scores for that board are ranked and the same separately for the NS scores. You are competing only against the other pairs sitting in the same direction. The highest ranked EW pair gets the most matchpoints (different to masterpoints) on the board, earning two for each EW pair with a lower score and one for a pair with the same score.
In our case with seven tables there were 12 matchpoints a board's top score then the second pair gets 10 and so on down to the bottom ranked pair who gets 0. At the end your matchpoints from all your boards are used to calculate your % (your total matchpoints as a % of the maximum possible - which would be if you got a "top" every board).
A passed in board scores 0 for both pairs. How many matchpoints you get depends on where 0 is ranked. In our case, every other EW pair got a positive score, half of them as declarer and half because NS went down. So 0 turned out to be the bottom ranked score for EW and the top for NS - 12 matchpoints for them and 0 for us!
This makes sense when you think about it as you shouldn't be rewarded for sitting on the sidelines when there is a makeable contract to be bid and played but you are rewarded if you hold back and your peers rush in and fail. Of course, what you can't control is what your particular opponents do. We were unlucky in the sense that our NS opponents were sensible but some other NS pairs bid and failed. On the other hand, we failed to find the available EW makeable contract.
You get the same sort of unpleasant surprise when you make your contract only to find you are bottom board because the others made overtricks and so scored higher.
Incidentally, a board that is not played (or bid) due to time shortage or some other reason is scored differently. "A not played board never exists as far as the two pairs' raw scores are concerned. If it means that they have played one less board than other pairs have played then their matchpoints on the boards they did play are factored up to adjust for their lower number of boards played. (This is the same adjustment process when a pair "sits out" some boards.) In effect NS who may have averaged 45% on their other boards would get an implicit 45% on the unplayed board through the factoring up process. EW who may have averaged 48% on the other boards would effectively get 48% on the unplayed board. A director might award an Average + or - depending on the pair's contribution to the delay or infringement." (David Farmer)
Note how these two different results are entered into the Bridgemate device - in the contract field, K is input for a passed-in board and 0 for a board not bid or played. The K key is also labelled PASS. The 0 key is labelled with a small 1 as well and is also used to enter the lead of a ten.
Not a lot of people know that, as Michael Caine never actually said.
