[blml] 60% session in IMPs

[Ben Schelen]

----- Original Message ----- 
From: "John Probst" <john at asimere.com>
To: "Bridge Laws Mailing List" <blml at amsterdamned.org>
Sent: Saturday, December 22, 2007 4:06 PM
Subject: Re: [blml] 60% session in IMPs


>
> ----- Original Message ----- 
> From: "Robert Geller" <geller at nifty.com>
> To: "Bridge Laws Mailing List" <blml at amsterdamned.org>
> Sent: Friday, December 21, 2007 1:51 PM
> Subject: Re: [blml] 60% session in IMPs
>
>
> > Hi,
> > In this case I agree completely with you that "the equivalent in
> > imps of a 60% session" is not well defined.
>
> We know that over 28 boards, 60% is 49 imps. (Data from 20 years of YC
> games, where we recorder the number of 60% scores and the spread of the
imps
> scores. However scores tend to increase at imps but decrease at pairs over
> larger number of boards. Since a square root Law applies to each, we can
> simply scale the imps to 20 boards; 20/28 x 49 is  35 imps.  We also know
> that for Butler scoring the 3 imp award shoul be rooot 3 x 7/6. whuch is
> nigh on 2 imps. This ties in nicely with the 35 imps for 20 boards.  If
you
> can be bothered try:
>
In the Netherlands 2 imps is recommended for butler sessions.

Ben