Join Bridge Winners
All comments by John Portwood
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Well it is in pre-dealt hands, but not every club uses them.

The number of imps NS make in a normal IMP event also depends on the EW distribution - so this element of luck is constant.

Not sure whether tactics would change
13 hours ago
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As I understand it - those NS who bid a game that should not have been bid i.e. bad bridge, lose 0 imps. Those EW who mis-defended the game that they should have got down (maybe on double dummy defence) lose 9 imps.

What it means is that you aren't penalised if opponents reach the par score - that is what they are supposed to do. If the par score is NOT reached then one pair has made a bad theoretical bridge call and are penalised.

The one problem I forsee is that whoever does the scoring (scorer or software) is going to have to know the par score. That would involve some additional software for the hand-creator (if a program) and there is always the chance that the scorer would get the par score wrong - for one thing they would need to look at the hands if they were not pre-dealt and work out the par score, which may not be easy unless the scorer is also an expert player, unless they enter every hand into Deep Finesse or the equivalent manually - and that would take a lot of time.
14 hours ago
John Portwood edited this comment 14 hours ago
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Does the fact that there will be fewer Imps scored affect the calculation to VPs and also NGS?

As you know, the NGS system use a multiplier to convert average imps/ hand into percentages. If the EBU accepted this scoring method then no doubt a different multiplyer would be required. This is pretty obvious from the fact that in one scoring system NS get 28.9/24 imps/ hand and in the other they get -103/24 imps per hand. That is quite a swing on a NGS score.
July 14
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OK - I was concerned that if no one beat par then one side would get no imps at all - and from that you canimagine a scenario where the par score on every hand is unobtainable for one side through the entire session - and all NS would end up on 0 (or 50%) even though there would be some variation on a standard IMP scale.
July 14
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So if the datum is NS + 430 and NS actually get +400

NS: -1 imp, EW 0 (EW get nothing since result was NS error.)

But if NS get +460

NS: 0 imp, EW -1 imp (NS get nothing since result was EW error)

Correct?
July 14
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I see no reason why you can't score in this method - in effect it is seeing how well you do compared to perfect bridge - and removes pretty well all luck from the event. The best players will still win as they will lose fewer imps.

To accept this method of scoring, though, you have to change your mentality.

And one more thing - it goes somewhat to ameliorate the complaints about ‘protecting the field’ and getting ‘unjustified tops’ because opponents have a bidding misunderstanding or one of those ridiculous 3H* -7 on a UI situation. (You still get 0 - opponents get -20, but you don't gain vast numbers of X-IMPS becuase everyone else was playing in the par score of +620 and had no opportunity to do anything better)
July 14
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The ruling does not state that the pause demonstrably suggests doubling: what it does state is that partner has extra values so that ‘not-passing’ might be succesful. By ‘not-passing’ the bidder has not ‘carefully avoided’ taking advantage of the UI - law 73C IIRC (which refers to 16B)
July 14
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Because the opponents might not be able to just go one-off at a higher level.

If the best that they can make is 1S then the optimum score for N/S is always +140.
July 14
$20
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In precision I have limited my hand - so I show suit. In 2/1 I have done neither - and I prefer to limit my hand. If I miss a 4-4 major fit (only happen when partner is 4-4 or more in the majors and a weakish hand) then so be it.
July 13
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If the EBU algorithm was applied worldwide then each country would be able to rank its players on a similar scale - BUT the scales would not be really equivalent as there would not be much diffusion of ranking between countries. A 60 player in the USA might not be equivalent to a 60 player in England or China (but they would be close due to the mathematics involved, central limit theorem etc)

Of course if BBO implemented the algorithm then that would be a different matter - everyone on BBO would have a grade. It would of course require results to be transferred over to the appropriate regulating authorities - unless the WBF kept the official database (and of course everyone was honest about their logins etc and required to provide a WBF number)
July 13
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The EBU have an article on their website - myths about the NGS

https://www.ebu.co.uk/documents/miscellaneous/ngs/clark-article.pdf

“The facts: In 2013 there were 1450
incidences of a 60+ player partnering
someone with a grade below 45. In 49.7%
of those sessions their grade went up.”

The NGS ranking does fluctuate - a single bad session (12% below par) can cause your grade to drop by about 0.5. Equally a great result can have the (desirable) opposite effect.

If you play with an erratic bidder whose ranking is 50 then you are definitely going to get a lower score than with your current partner: however your expert bidding is only one aspect of the game - as I mentioned; and if the reason why your partner's relatively low NGS rank is because of his erratic bidding then he will have other skills that are above an average player to compensate. (And if you can teach him to NOT be an erratic bidder then his overall ranking will improve and so will yours. Playing with improving players is a good way to cheat the system)

There are only 8 players in the EBU who have a ranking of 70 or more and 51 others who have a ranking of 67 (A). I don't think is unreasonable that if two of them played together that they could achieve 80% against players of such ability: and if they played (as a pro?) with a 40% player then they ‘only’ have to get 65% to match par. (70% + 40%)/2 (average grade) - 40% (standard of opponents). Now then in a single short session there is probably too much randomness to guarantee attaining this, but in a very long session you will tend towards your expected result. (The NGS ranks by the number of boards you play in the session rather than the number of sessions only.)

Yes the NGS is intresting fun - however there is certainly a strong correlation between perceived skill of players and NGS ranking.

(I note that A is the most popular choice to being an expert. On Tuesday Morning I was an expert - on Wednesday morning I wasn't.)
July 13
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There are about 1000 Aces and 1000 Kings out of approx 46,000 players.

For those who are not conversant with the system - each grade represents a 2% improvement in expected results - so an 8 has a grade of 49-51 and would be expected to finish in this range when they played an average field with an average partner.

A king starts at 59% and an Ace of Spades at 67% so an Ace of Spades player is expected to get nearly twice as much above average as a King. (The highest players of course don't play much in events where the average grade is 50)

There are other factors - if you play only with one player and he plays only with you then you will both by definition have the same grade - even if one of you (your partner of course) is weaker than the other. Some players will refuse to play in unfamiliar partnerships worrying (wrongly) that it will adversly affect their grade. (And I will play bridge with anyone of any grade - I recently played with a ‘2’ although my regular partner is a Jack. I have a keen player in another partnership who is a 9.)

As I do not regard myself as an expert at the table (other than as dummy) then the minimum ranking would be a high A - however it depends what you mean as an expert.

1) Some have their grade due to years of fine-tuning their bidding system, so they get to the right contract.

2) Some have great table presence (we'll assume that means reading opponents mannerisms not your partner's)

3) Some can play the spots off the cards - great technicians.

4) Some are much better at defence than others.

To be an ‘expert’ you have to be good at all these:

The highest ranked player at the moment (Andrew Robson) has an (evolving) ranking of 74.68: his partner (Tony Forrester) has a ranking of 67.61 - which means that Mr Forrester has a ranking as much below Mr Robson as I am below Mr Forrester. Is Mr Forrester an Expert? Yes - am I an expert? - No. (I am ranked 860th on evolved grades and 1032nd on all grades)
July 12
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Well if we teach AIs bridge there will be no danger of them taking over the world - they'll all be screaming and shouting at each other for taking the wrong line or making a bid that turned out badly.
July 12
ATB
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Depends on partnership agreement I suspect. But what can North bid over 3?

Maybe South was unsure as whether he could stop the run of the heart suit.
July 10
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If the diamond had been obvious without the UI then presumably there was no LA and so could have been led,
July 8
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Well first of all - since NS by their own admission might “possibly” reach 4 we have to give some benefit to 3 +1.

Since “possibly” means less than 50% then a 50-50 weighting seems reasonable as to the contract - and since Steve says “that takes some care” we have to allow some %ge of 9 and some %ge of 10. - say 80% 20%

Putting this together (80-20)

40% : 4 making : 50% X 80%
40% : 3 +1 : 50% X 80%
10% : 3 making : 50% X 20%
10% : 4 -1 : 50% X 20%

(Other weighted rulings are available)

Edit

When did East give the correct explanation? The law says he should do it before the end of the auction period. In which case South would have had the opportunity to bid 3
July 6
John Portwood edited this comment July 6
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Just to note on the OP commentary - the potential adjustment is not due to an “extremely serious error unrelated to the infraction” - which covers things like revokes, failing to call the TD, bidding on when doubled for penalties. Had 4 Spades not been bid EW would not be in a position of having to decide whether to double or not - so failure to double is defintely related to the infraction. it is “or by a gambling action, which if unsuccessful it might have hoped to recover through rectification”

Obviously passing (or doubling) is a gambling action. I think we have to decide whether the evidence is clear that (absent the BIT) EW would pass or EW would double.

As John says, in club bridge doubling is much less common. Many players will feel that “if the contract is going down then I'm getting a good score anyway because opponents have misbid” and fail to see the logic of doubling when, if it fails, they get a bottom.
July 6
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The revoke is established. Law 63A1

1. when the offender or his partner leads or plays to the following trick (any such play, legal or illegal, establishes the revoke).

Had this been trick 12 rather than trick 11 then the rectification is different, but the revoke is still established.

Defence lose their trick.
July 3
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The revoke card (5) did not win a trick and the circumstances do not fall under Law 64B so there is a one trick penalty. (Law 64A2)

The next question is whether the defence have been damaged by more than one trick (Law 64C). Since declarer has 7 top tricks the answer appears to be no. So no further rectification.

2NT -1.
July 3
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Love that Qa8 move! Obvious - when you see it!
July 2
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