Trinidad, on 2015-February-04, 08:42, said:
While I agree with the rest of your post, this part is incorrect. The figure of 3 IMPs for teams of four is not rounded to a nearest integer. It is defined by the laws (Law 86A). That means that the value of 3 IMPs has absolute accuracy and anything derived from it does not carry any inaccuracies from the value of 3 IMP. So, reporting 2.12 IMP for Cross-IMPs is not silly at all.
It's still silly. The 3 IMPs that is defined in the laws is "in IMP play". That applies just as much to cross-imps as to teams of four. So if you are taking 3 IMPs as an absolute value handed down by law, then average-plus for cross-imps should be 3.00 IMPs.
The EBU decided to use their powers (given in Law 86A) to vary the value of average-plus in IMP play. Earlier editions of the WB gave a formula to be used for various numbers of tables. IIRC the figure for teams of four did in fact work out at 3 IMPs, but only after rounding.