MP vs IMPs
#41
Posted 2014-December-19, 03:40
Madam, you are a fakir and a fraud. You are an idiot turned loose with a computer and a first year grad student's knowledge of statistics.
You present a double dummy playing analysis based on a potentially very biased sample.
#42
Posted 2014-December-19, 09:12
Cthulhu D, on 2014-December-18, 22:55, said:
#43
Posted 2014-December-19, 09:27
jdeegan, on 2014-December-19, 03:40, said:
#44
Posted 2014-December-19, 16:15
jdeegan, on 2014-December-19, 03:40, said:
Madam, you are a fakir and a fraud. You are an idiot turned loose with a computer and a first year grad student's knowledge of statistics.
You present a double dummy playing analysis based on a potentially very biased sample.
I can do a written analyze at 20 boards per hour speed. If that was my day job it would take only 3 months to analyze 9000 bridge hands.
But actual arguments for practical randomness in IMP vs MP games.
Normal winner score in MP is around 57-65% in competitions where skill level difference aren't big. If a tournament is about 40 boards then single board top-bottom difference is 2.5% in end results. But in practical play my opponents cannot score more than 2/3 of top with a good play. That translates to about 1.6% at stage each board which is 1/9 of score difference between winner and average. But even a good play can be often countered with a less important decision that still score a few points back to side that didn't have the more important decision to make.
At similar IMP competition winner score is +1.5-2.5 IMP per board per comparison. But a single vulnerable game swing is 10-14 IMPs per comparison. That translates to about 0.25-0.35 IMPs per board and those decision are pretty common with only one side having decisions that affect the make or not make situation. So even a normal game swing has a higher magnitude in IMPs than extreme maximum MP games offer. But if we factor in some extreme IMP swings with small slam their effect can be even twice the effect that games have. That makes IMP scoring more volatile because smaller number of important decision provide relatively higher magnitude changes to the results.
#45
Posted 2014-December-19, 16:51
suokko, on 2014-December-19, 16:15, said:
But actual arguments for practical randomness in IMP vs MP games.
Normal winner score in MP is around 57-65% in competitions where skill level difference aren't big. If a tournament is about 40 boards then single board top-bottom difference is 2.5% in end results. But in practical play my opponents cannot score more than 2/3 of top with a good play. That translates to about 1.6% at stage each board which is 1/9 of score difference between winner and average. But even a good play can be often countered with a less important decision that still score a few points back to side that didn't have the more important decision to make.
At similar IMP competition winner score is +1.5-2.5 IMP per board per comparison. But a single vulnerable game swing is 10-14 IMPs per comparison. That translates to about 0.25-0.35 IMPs per board and those decision are pretty common with only one side having decisions that affect the make or not make situation. So even a normal game swing has a higher magnitude in IMPs than extreme maximum MP games offer. But if we factor in some extreme IMP swings with small slam their effect can be even twice the effect that games have. That makes IMP scoring more volatile because smaller number of important decision provide relatively higher magnitude changes to the results.
I agree re: Variance. Jeff has done some analysis of this here: http://www.jeff-gold...rg/bridge/study
#46
Posted 2014-December-19, 17:53
nige1, on 2014-December-19, 09:27, said:
One should only be able to start a thread like if one has a phd in statistics.
Oh, wait ...
#47
Posted 2014-December-19, 18:10
- called "an idiot turned loose with a computer and a first year grad student's knowledge of statistics", and
- gets mansplained (in another thread) the most basic thing one could explain about standard variance.
I am sure one could explain this without referring to sexism, but I doubt it would lead to the easiest explanation.
#48
Posted 2014-December-19, 18:13
cherdano, on 2014-December-19, 18:10, said:
- called "an idiot turned loose with a computer and a first year grad student's knowledge of statistics", and
- gets mansplained (in another thread) the most basic thing one could explain about standard variance.
I am sure one could explain this without referring to sexism, but I doubt it would lead to the easiest explanation.
ignorance and internet behavior
https://www.youtube....hungPlaysBridge
#49
Posted 2014-December-19, 19:02
cherdano, on 2014-December-19, 18:10, said:
- called "an idiot turned loose with a computer and a first year grad student's knowledge of statistics", and
- gets mansplained (in another thread) the most basic thing one could explain about standard variance.
I am sure one could explain this without referring to sexism, but I doubt it would lead to the easiest explanation.
By an astounding coincidence, they are the two people on my ignore list - I only saw the posts because their idiocy was quoted for posterity ...
#50
Posted 2014-December-20, 08:12
George Carlin
#51
Posted 2014-December-20, 10:49
#53
Posted 2014-December-20, 14:41
- Work out the average rank (as a percentile) of a selection of top pairs over lots of world-class MP pairs events.
- Also work out a their average percentiles at similar cross-imp pairs events.
- Then see how well these two over-all rankings correlate with their rankings in each individual event. Perhaps, also future events.
- The higher the correlation, the better the measure of skill? Especially if one form of scoring dominates the other as a predictor.
#54
Posted 2014-December-20, 14:56
nige1, on 2014-December-20, 14:41, said:
LOL.
-- Bertrand Russell
#55
Posted 2014-December-20, 14:57
But you need somehow to take into account that the fields could be more homogenous in one type of events than in the other. Suppose, for example, that the skill factor is really the same at both forms of scoring, and the IMP and MP tourneys are similar w.r.t. size and balance. However, IMP tourneys attract fewer weak pairs. So the relative ranking of the top pairs will be more stable at IMPs because there is less randomness associated with sitting in the same seat as a weak pair on a particular board.
So unless you have data where identical fields play some IMP tourneys and also some MP tourneys, the analysis is not trivial.
#56
Posted 2014-December-20, 15:01
Thank you Helene_t.
Perhaps it would be better to use the ranks of the selected pairs relative to each other and ignore all other competitors?
#57
Posted 2014-December-20, 15:20
#58
Posted 2014-December-20, 16:04
not so with statistics
#59
Posted 2014-December-20, 17:04
-- Bertrand Russell
#60
Posted 2014-December-20, 17:26