Garden Cities Trophy
I'm running a qualifier event for this competition, and I want to use the same scoring method as the actual competition. I can't find it on the website - does anyone know what it is? (I would assume X-imps but I thought I ought to check)
Comments
Imp the 2 To4 results ,add them together then convert to VPs, using twice the normal scale. So 8 board matches use the 16 board scale etc.
I found this on a discussion board:
_The English Bridge Union (EBU) Recommends using a modified IMP scale for scoring teams of 8 matches. It is obtained by multiplying the standard IMP scale by √2.
_
Does anyone know where it exists on the EBU site?
That discussion probably refers to adding all scores together (aggregate) before Imping (Add then Imp). Look at EBU White Book page 49 for T of 8 scoring (not using Ximps) using Imp the Add.
There are three ways to score teams of 8: "add then IMP" (i.e. you add the total points scored at each table, then convert the total to IMPs); cross-IMPs, where you IMP each of the four possible comparisons and then add them together (or equivalently, average them); and the multiple teams approach, where you basically split each team into half, have it play a team match against the corresponding half of the other team (scored in IMPs as usual), then add the results for the two half-teams together.
The first of these three methods, "add then IMP", is the only method that uses a modified IMPs scale. The scale can be found in section 3.7.1 of the White Book. The modified IMPs scale is recommended for use only in this situation, and not in other forms of scoring a teams-of-8 match. ("Add then IMP" is generally not recommended as a scoring method for teams of 8, however – modifying the IMP scale makes it a little less bad, but the other methods are fairer.)
However, the Garden Cities Trophy doesn't use add-then-IMP scoring, so the modified IMPs scale isn't relevant in that situation. (The White Book 3.7.1 suggests it uses the third method, scoring multiple-teams-style; @Triffid explained the details above.)