[blml] 60% session in IMPs

[John Probst]

----- 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:

http://www.asimere.com/BridgeArticles/VPScales.htm

which contains all the math necessary to compute the equivalent mps score 
from imps.  I think the Laws cover it well; they don't say we can't use 
maths, and they do say we can devise any form of scoring.  John
> -Bob
>
>
> Konrad Ciborowski $B$5$s$O=q$-$^$7$?(B:
>>Hi,
>>
>>It's me again.
>>
>>L12C2c
>>
>>"The foregoing is modified for a non-offending contestant that
>>obtains a session score exceeding 60% of the available
> matchpoints or
>>for an offending contestant that obtains a session score that is
> less
>>than 40% of the available matchpoints (or the equivalent in
> imps).
>>Such contestants are awarded the percentage obtained (or the
>>equivalent in imps) on the other boards of that session."
>>
>>What is the equivalent in imps of a 60% session?
>>
>>In an IMP session of 20 deals (Butler scoring)
>>the highest possible score is 24 IMPs x 20 = 480 IMPs.
>>60% of that is +288 IMPs a score almost unheard of.
>>
>>    Does this mean that we award +3 as average plus in a 20 deal
>>IMP session unless the contestant's score is +288 IMPs
>>in which case we award him another 288 IMPs as average plus
>>(his session score) making his score +578 IMPs?
>>
>>Makes no sense to me.
>>
>>It looks that the remarks in parenthesis about the
>>equivalent in IMPs were added "without pause for thought".
>>Or, as usual, I'm missing something that is obvious to the rest
> of
>>the world.
>>
>>
>>
>>
>>-- 
>>Konrad Ciborowski
>>Krak$B".(B, Poland
>>
>>-----------------------------------------------------------------
> -----
>>Diverse Extreme Team Goes Dakar
>>>> http://link.interia.pl/f1ca9
>>
>>
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>
> -----------------------------------------------------
> Robert (Bob) Geller,     Tokyo, Japan        geller at nifty.com
>
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