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Unusual distributions became the "norm" Cards distribution defies statistics

#1 User is offline   00__0906 

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Posted 2019-December-08, 15:10

I tried this before, I try again because it is ill serving the bridge.

Why 5-0, 4-1 distribution is found more often than 3-2 on BBO?
Why Qx after the KJxx is 90% true?

I can keep on, but I hope you get the message.

BECOME NORMAL People!

Thanks,
Mihai Buta
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#2 User is offline   smerriman 

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Posted 2019-December-08, 16:50

Read the responses to your last two threads. Posting the same thing three times, and making up numbers with 0 evidence, is silly.
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#3 User is online   hrothgar 

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Posted 2019-December-08, 17:07

 smerriman, on 2019-December-08, 16:50, said:

Read the responses to your last two threads. Posting the same thing three times, and making up numbers with 0 evidence, is silly.


God damn you're stupid.

Persistent, but very very stupid.
Alderaan delenda est
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#4 User is offline   nige1 

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Posted 2019-December-08, 21:37

 00__0906, on 2019-December-08, 15:10, said:

I tried this before, I try again because it is ill serving the bridge.Why 5-0, 4-1 distribution is found more often than 3-2 on BBO? Why Qx after the KJxx is 90% true? I can keep on, but I hope you get the message.
.
I haven't encountered this phenomenon but Mihai Buta isn't the only member to complain about non-random suit-distribution and honour-placement. Complainers should substantiate their suspicions with statistics from a reasonable size random sample of consecutive deals. However, it would also be a kind gesture by BBO, to publish relevant actual statistics, reassuring us all.
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#5 User is offline   smerriman 

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Posted 2019-December-08, 22:21

OK, let's put this to bed once and for all. I just grabbed the last 2000 challenge-a-robot hands from BBO. Handviewer URLs, one per line, are in the text file uploaded here (with names removed for privacy).

Claim 1: 5-0, 4-1 distribution is found more often than 3-2

Over the 2000 hands, there were 1233 instances (can be more than one per deal) of North/South holding an 8 card fit. The breaks were:

5-0: 1.78%
4-1: 13.06%
3-2: 34.14%
2-3: 33.98%
1-4: 15.09%
0-5: 1.95%

Result: completely false.

Claim 2: Qx after KJxx is 90% true

Over the 2000 hands, there were 589 occasions of North or South holding KJ and an opponent holding the queen.

The queen was onside on 52.3% of those occasions (margin of error 4%)

Result: completely false

Claim by other people: BBO deals are more distributional than they should be.

South's hand over the 2000 deals:

4-4-3-2 - 20.75%
5-3-3-2 - 16.15%
5-4-3-1 - 13.25%
4-3-3-3 - 10.3%
5-4-2-2 - 9.75%
6-3-2-2 - 6.2%
6-4-2-1 - 5.3%
6-3-3-1 - 3.15%
5-5-2-1 - 2.85%
7-3-2-1 - 2.65%
4-4-4-1 - 2.25%
5-4-4-0 - 1.25%
6-4-3-0 - 1.2%
6-5-1-1 - 1.1%
5-5-3-0 - 1.05%
6-5-2-0 - 0.75%
7-4-2-0 - 0.6%
7-4-1-1 - 0.55%
7-3-3-0 - 0.3%
7-2-2-2 - 0.25%
8-3-2-0 - 0.1%
8-4-1-0 - 0.05%
8-2-2-1 - 0.05%
7-5-1-0 - 0.05%
6-6-1-0 - 0.05%
9-2-2-0 - 0.05%

This lines up with the table here very nicely.

Result: completely false.
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#6 User is offline   zhammer 

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Posted 2019-December-09, 00:11

Easy to figure out if this is indeed a BBO issue or just your mind is playing games with you.

Get a piece of paper, everytime when you are declarer and see KJxx, try not to finesse and take any other line and see if it works. Then tabulate and see if your statement has any validity.

Afterall, you may have discovered how to win many more match points.
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#7 User is online   hrothgar 

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Posted 2019-December-09, 03:34

 smerriman, on 2019-December-08, 22:21, said:

OK, let's put this to bed once and for all. I just grabbed the last 2000 challenge-a-robot hands from BBO. Handviewer URLs, one per line, are in the text file uploaded here (with names removed for privacy).


Thanks for doing this
Alderaan delenda est
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#8 User is online   hrothgar 

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Posted 2019-December-09, 03:35

 nige1, on 2019-December-08, 21:37, said:

it would also be a kind gesture by BBO, to publish relevant actual statistics, reassuring us all.


BBO has published statistics (long long ago)
As smerriman notes, you can also download hand records and run whatever tests you want.

As a rule, the preliminary burden of proof should be on people making stupid claims
Alderaan delenda est
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#9 User is offline   johnu 

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Posted 2019-December-09, 04:09

 smerriman, on 2019-December-08, 16:50, said:

Read the responses to your last two threads. Posting the same thing three times, and making up numbers with 0 evidence, is silly.

This might be the time for another public service announcement.

If you want to get better suit breaks and honors located where your finesses work, you need to subscribe to premium services.

A. Silver Premium membership - "normal" distributions, but finesses only work about 25%
B. Gold Premium membership - "normal" distributions, and finesses work 50%
C. Double Platinum membership - you always get the most even breaks, and finesses work 90%

I have been completely satisfied with my Double Platinum membership. I'm planning to get the One Peek is Worth 2 Finesses add-on package when I get a raise in salary at my work.
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#10 User is offline   pigpenz 

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Posted 2019-December-09, 13:46

I agree this totally nonsense, I have played here for 15 years, the more hands you play the more weird distributions
you will see just from the shear # of hands you play. If your not doing well then you need to practice more.
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#11 User is online   pescetom 

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Posted 2019-December-09, 15:18

I do hope the author of this post will now apologize and move on.
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#12 User is offline   pink flag 

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Posted 2019-December-09, 15:53

 pescetom, on 2019-December-09, 15:18, said:

I do hope the author of this post will now apologize and move on.

Before blaming Mihai Buta it would be good to differentiate...

1) Playing NOT robot tournaments, the distribution is always normal, like it was shown here.

2) Playing robot tournaments, the probability changes in my opinion (I play approximate 5-10 robot tournaments every day) dramatically. That game ISN'T a game of probability anymore, it is a diss game. A 50% chance becomes at best a 25% chance, a 75% chance becomes at best a 30% chance and so on. When i bid slams in a 8 card fit, unbelieavble often the cards in opps hands are 4/1 or even 5/0. It's extremely frustrating, to often bid very good contracts and then to go down far to often, cos probability is not ok.

3) The question is: WHY does BBO this in robot tournaments? I think i know the reason, but its only a guess, so i will not tell here.
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#13 User is online   pescetom 

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Posted 2019-December-09, 16:14

 pink flag, on 2019-December-09, 15:53, said:

Before blaming Mihai Buta it would be good to differentiate...

I blame him for repeating unstubstantiated claims (now proven false), and hope he will admit his mistake.

 pink flag, on 2019-December-09, 15:53, said:

1) Playing NOT robot tournaments, the distribution is always normal, like it was shown here.

2) Playing robot tournaments, the probability changes in my opinion (I play approximate 5-10 robot tournaments every day) dramatically. That game ISN'T a game of probability anymore, it is a diss game. A 50% chance becomes at best a 25% chance, a 75% chance becomes at best a 30% chance and so on. When i bid slams in a 8 card fit, unbelieavble often the cards in opps hands are 4/1 or even 5/0. It's extremely frustrating, to often bid very good contracts and then to go down far to often, cos probability is not ok.

smerriman analysed data from "challenge-a-robot", are robot tournaments something different?
If so, the onus is obviously on you to perform a similar analysis and justify your claims, unless the data is unavailable for some reason.
Opinion doesn't cut it here.
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#14 User is offline   nige1 

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Posted 2019-December-09, 16:17

Mihai Buta and Pink Flag don't need to apologize if they can just present a reasonable-size sample of layouts that justify their claims. For example, urls for a complete week of consecutive deals from their robot-tournaments..
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#15 User is offline   pink flag 

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Posted 2019-December-09, 16:31

 nige1, on 2019-December-09, 16:17, said:

Mihai Buta and Pink Flag don't need to apologize if they can just present a reasonable-size sample of layouts that justify their claims. For example, urls for a complete week of consecutive deals from their robot-tournaments..

I won't do that, cos i arranged my game with the diss distributions. I talked to approximate 10 players, who feel exactly the same as me (all are very good players). If anyone believes this ok, if not, ok. But the way Mihai Buta is attacked here by some members is simply disgusting. Belive in what you want, but don't blame someone for an opinion.
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#16 User is offline   sfi 

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Posted 2019-December-09, 17:17

 pink flag, on 2019-December-09, 16:31, said:

But the way Mihai Buta is attacked here by some members is simply disgusting. Belive in what you want, but don't blame someone for an opinion.

It's fine to have an opinion. But that's different from repeatedly accusing the people running the site of fixing the games and then lying about it, which is exactly what the original poster has done over several months. Having data to back up a claim like that is valuable supporting evidence.
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#17 User is online   hrothgar 

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Posted 2019-December-09, 19:08

 pink flag, on 2019-December-09, 15:53, said:

Before blaming Mihai Buta it would be good to differentiate...

1) Playing NOT robot tournaments, the distribution is always normal, like it was shown here.

2) Playing robot tournaments, the probability changes in my opinion (I play approximate 5-10 robot tournaments every day) dramatically. That game ISN'T a game of probability anymore, it is a diss game. A 50% chance becomes at best a 25% chance, a 75% chance becomes at best a 30% chance and so on. When i bid slams in a 8 card fit, unbelieavble often the cards in opps hands are 4/1 or even 5/0. It's extremely frustrating, to often bid very good contracts and then to go down far to often, cos probability is not ok.

3) The question is: WHY does BBO this in robot tournaments? I think i know the reason, but its only a guess, so i will not tell here.


The quality of the trolls is really declining...

Can we send this one back and get something better?
Alderaan delenda est
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#18 User is offline   barmar 

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Posted 2019-December-09, 20:49

While the answers here are technically correct, I apologize for hrothgar's language, and I've asked him to tone down his style outside the Water Cooler.

#19 User is offline   nige1 

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Posted 2019-December-09, 21:06

 nige1, on 2019-December-09, 16:17, said:

Mihai Buta and Pink Flag don't need to apologize if they can just present a reasonable-size sample of layouts that justify their claims. For example, urls for a complete week of consecutive deals from their robot-tournaments..

 pink flag, on 2019-December-09, 16:31, said:

I won't do that, cos i arranged my game with the diss distributions. I talked to approximate 10 players, who feel exactly the same as me (all are very good players). If anyone believes this ok, if not, ok. But the way Mihai Buta is attacked here by some members is simply disgusting. Belive in what you want, but don't blame someone for an opinion.
It's a question of fact not belief. If your good players can't be bothered to submit (presumably) readily available data to substantiate their nebulous claims, it's hubris to expect Smerriman or BBO to waste more time disproving them :)
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#20 User is offline   mlbridge 

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Posted 2019-December-09, 23:31

I played in mostly the $1 robot rebate tourneys. My experience is that the distribution is abnormal in those tourneys. To illustrate, I am pulling the two most tourneys. I am showing the distribution of north (my dummy partner).

I coded the hands if B (balance), S (single suited), T (two suited) and 3 (three suited).

This post is for tourney #612, played on 12/10/2019.

Of the 12 hands for N, 5 were balanced, 5 were single suited and 2 were two suited. Clearly the percentages don't match the probability.

More startling is if one looks closer at the single suited hands. One have less than 1% of occurring and 2 have 1.3% chance. So of the 12 hands, N was dealt 3 hands were about a 1% chance of occurring.

#612
#1 S 6-3-2-2
#2 S 6-4-3-0 %0.0132623
#3 B 4-3-3-3
#4 T 5-4-2-2
#5 S 6-4-2-1 %0.0470207
#6 S 7-2-2-2 %0.00512954
#7 B 4-4-3-2
#8 S 6-4-3-0 %0.0132623
#9 B 5-3-3-2
#10 B 4-3-3-3
#11 B 5-3-3-2
#12 T 5-4-2-2
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