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I notice in the image that the cards also are printed offset. Well actually probably cut offset. The border on the red cards is wider on one long edge than the other. It does not appear to be the case on the blue cards. So this might be accidental. Even such a small discrepancy could be easily exploited.

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Chess: In standard games you are allotted a certain amount of time (90 minutes) for the first forty moves then an additional 30 minutes after forty moves and also an additional 30s for every move.

Basketball: The shot clock is only started when your side is in possession. For the NBA it is 24 seconds.

In bridge the time considerations are much more complex. In chess it the game starts equal and therefore it seems completely uncontroversial that both sides will have equal amounts of time. In basketball teams can have as many possessions as they earn or obtain in the course the game. That number of possessions is not necessarily balanced with the other team and the possessions do not need to last the entire 24 seconds and there is no time bank accrued if you save some time.

In bridge the game does not start equal. On any given board one side might have all or none of the decisions or anywhere in between. Some of those decisions are independent of the opponents and are based on the lay of the cards. It is not obvious in that situation that it is fair for time to be allocated equally but neither is it obvious how to allocate the time unequally.

The use of time might depend on whether we are bidding/doubling/redoubling or passing; the auction is at a high level; the complexity of the auction; competitive or not competitive auction; whether a bid is a routine system bid (1NT opening) or a delicate judgement call. Similarly, in the play there are differences for the opening lead; declarer; defender; obvious plays; and subtle or otherwise difficult plays perhaps based on judgement and calculation.

The game does not deal out these situations anything like equally especially in the short run like two board rounds or even 16 board stanzas.

It is ridiculous to divide up the two hours twenty minutes or whatever for 16 boards and say each player has 35 minutes each or each side has 70 minutes each. The game does not play like that.

To be fair any equality needs to be over a long run not a short run.

There are many ideas but there are flaws. Not sure if there is an ideal solution.

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I also just did a simulation. I assumed that you would win a prize about 1/3 which is the average from your sample of 12 tournaments. I then simulated sets of 12 tournaments and counted the prizes in groups of 5 and 7 tournaments.

The chance of winning three or more prizes in five randomly selected tournaments and one or fewer prizes in the other seven tournaments was around 550 out of 10000. So not quite at the 95% level.

Interestingly the most common number of tournament wins is 2 out of 5 and 2 out of 7 which is only one away from your result in each sample. This illustrates how not extreme your result might be.

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Sample 1 Sample 2 Sample Proportion 0.6 0.142857 Sample size 5 7 Significance level 0.05 1- or 2-tailed test 2-tailed

Sample 1 Sample 2 Difference Sample proportion 0.6 0.142857 0.457143 95% CI (asymptotic) 0.1706 - 1.0294 -0.1164 - 0.4021 -0.0839 - 0.9981 z-value 1.7 P-value 0.0977 Interpretation Not significant, accept null hypothesis that sample proportions are equal n by pi n * pi <=5, test inappropriate

But it says the test is inappropriate as the sample size times the estimated probability is less than some magical number 5.

There is probably a more appropriate test for small samples but I suspect the result is likely to be the same that this difference that superficially seems large (3/5 compared with 1/7) is not statistically significant (for such a small sample size).

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In particular we need very little to make 5♠, two aces and a working finesse might do it. Of course there are other layouts where 5♠ is horribly wrong. Hence it is a problem. Or at least I thought it was.

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Not sure what they are doing but I know that I spoke to a National Director about this problem around 18 months ago and nothing seems to have happened.

I have been curious about the markings but have not taken out multiple packs to see if I could discern the pattern.

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Partner jumped to 4♦. Not sure what 3♦ would have meant for that partnership. The partnership bidder also had 4♣ available. Not sure why 4♦ in particular was chosen.

Not sure that many will have discussed this particular auction but I suspect some might have a generic agreement that 3♦ is natural. A bid of the opponent's suit after two suits have been bid. I suspect that would not apply to clubs when a six card club suit was shown.

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I haven't confirmed the markings on the problem decks. However there are many 10s if not 100s of decks in circulation that have overtly different backs.

The way cards are usually manufacturered and printed as uncut sheets that are then cut into individual playing cards means that it is reasonably likely the markings are consistent from deck to deck. If so anyone who knows the markings would be able to instantly recognise the ♠A or any other card.

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Nigel there are actual marked cards being used in some tournaments. They are relatively new decks but they have been used for a couple of years now. NZ Bridge have been aware of the problem cards since around 2018 to the best of my knowledge and recall.

Wayne Burrows

Wayne Burrows

Wayne Burrows

Basketball: The shot clock is only started when your side is in possession. For the NBA it is 24 seconds.

In bridge the time considerations are much more complex. In chess it the game starts equal and therefore it seems completely uncontroversial that both sides will have equal amounts of time. In basketball teams can have as many possessions as they earn or obtain in the course the game. That number of possessions is not necessarily balanced with the other team and the possessions do not need to last the entire 24 seconds and there is no time bank accrued if you save some time.

In bridge the game does not start equal. On any given board one side might have all or none of the decisions or anywhere in between. Some of those decisions are independent of the opponents and are based on the lay of the cards. It is not obvious in that situation that it is fair for time to be allocated equally but neither is it obvious how to allocate the time unequally.

The use of time might depend on whether we are bidding/doubling/redoubling or passing; the auction is at a high level; the complexity of the auction; competitive or not competitive auction; whether a bid is a routine system bid (1NT opening) or a delicate judgement call. Similarly, in the play there are differences for the opening lead; declarer; defender; obvious plays; and subtle or otherwise difficult plays perhaps based on judgement and calculation.

The game does not deal out these situations anything like equally especially in the short run like two board rounds or even 16 board stanzas.

It is ridiculous to divide up the two hours twenty minutes or whatever for 16 boards and say each player has 35 minutes each or each side has 70 minutes each. The game does not play like that.

To be fair any equality needs to be over a long run not a short run.

There are many ideas but there are flaws. Not sure if there is an ideal solution.

Wayne Burrows

A full description would be helpful too.

Wayne Burrows

Wayne Burrows

Such is the weird world of standard American.

Wayne Burrows

The chance of winning three or more prizes in five randomly selected tournaments and one or fewer prizes in the other seven tournaments was around 550 out of 10000. So not quite at the 95% level.

Interestingly the most common number of tournament wins is 2 out of 5 and 2 out of 7 which is only one away from your result in each sample. This illustrates how not extreme your result might be.

Wayne Burrows

I used this cool site https://epitools.ausvet.com.au/ztesttwo

But it says the test is inappropriate as the sample size times the estimated probability is less than some magical number 5.

There is probably a more appropriate test for small samples but I suspect the result is likely to be the same that this difference that superficially seems large (3/5 compared with 1/7) is not statistically significant (for such a small sample size).

Wayne Burrows

Wayne Burrows

Wayne Burrows

I can't see it on the webpage and it was not in the general bridge player email sent out today.

Wayne Burrows

Wayne Burrows

A Mexican 2♣ is even better.

Wayne Burrows

Wayne Burrows

I have been curious about the markings but have not taken out multiple packs to see if I could discern the pattern.

Wayne Burrows

Not sure that many will have discussed this particular auction but I suspect some might have a generic agreement that 3♦ is natural. A bid of the opponent's suit after two suits have been bid. I suspect that would not apply to clubs when a six card club suit was shown.

Wayne Burrows

What is the definition of private anger confidential?

Wayne Burrows

Wayne Burrows

The way cards are usually manufacturered and printed as uncut sheets that are then cut into individual playing cards means that it is reasonably likely the markings are consistent from deck to deck. If so anyone who knows the markings would be able to instantly recognise the ♠A or any other card.

Wayne Burrows

Who knows if anyone is taking advantage of this.