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August 2014 English Bridge

www.ebu.co.uk

EBU News

THE EBU's National Grading Scheme has

been with us for more than two years now

and most people find it both fun and

interesting. We do hear some criticism,

but it often has a root in a few common

misunderstandings, which we hope this

article will clear up for you.

Myth 1: You're disadvantaged when

you play with a weak partner

We hear this one quite a lot. Someone will

claim that they no longer want to play

with poor Mr P, who hasn't scored above

50% since the late sixties, because it will

damage their NGS grading. However,

they're worrying about nothing. If both

players are correctly graded, then it

doesn't matter what the individual

strengths are - the NGS takes this into

consideration.

The maths is quite simple: if Mr P is

graded 30, you're graded 50, and you're

playing in a field of average strength (50),

then your expected score will be just 40%.

If you do better than this, your grade will

go upÍž if you do worse your grade will go

down.

The NGS should actually make you

more keen to play with Mr P. In the old

days you had nothing tangible to gain

from playing with him - you were unlikely

to win any master points or beer vouchers.

With the NGS, though, you have a real

goal to aim for and can take some pride in

eking out a well-earned 42%, to improve

both your grades.

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.

Myth 2: You're disadvantaged

playing with an irregular partner

This is another common one and it sticks

around because there is some truth to it. If

you play only with regular partners you

will clearly have a higher grade than some one

of the same ability who plays only

with pick-up partners. But how much does

this matter? We estimate that the

difference is about 2% between the two

ends of the spectrum, so that means that if

you suddenly play with a new partner,

having only played with regular partners

previously, and your new partner is in the

same position, you'll need to get about 4%

more than usual to break even.

But this is extreme. In reality you'll play

with a range of partners, some more

regular than others, and your partnerforming

habits will already be built into

your NGS grade. When you play with the

newer partners, you'll be a tiny bit

disadvantaged, but when you go back to

playing with the regular partners you'll be

correspondingly rewarded.

It should also be noted that there is a

provision in the NGS for hosts/mentors to

exempt themselves, so if you are worried

about this you can choose to take up this

option by letting the director know before

the session starts. Of course, you're not

allowed to change your mind if you

happen to do well!

The facts: In 2013 there were 80,000

partnerships who had played fewer than

50 boards together. Almost exactly 50%

of those partnerships improved their

grade.

Myth 3: Your grade is always 100%

accurate

Myth 4: Your grade never changes

relative to other players

As much as we'd like to think otherwise,

there is still a lot of luck in bridge. You

don't always score exactly what you're

expected to score. Some weeks you get a

lot of gifts and your mistakes don't costÍž

other weeks you can't seem to do a thing

right. Your NGS grade will naturally

fluctuate around your true grade, and we

estimate that the standard deviation is

about 2%. This means that most of the

time your grade will be within one grade

band of your true grade; sometimes it will

be two grade bands out, but more extreme

cases will be rare. Here's an example graph

of a regular player's grade over time. You

can see yours by logging into the members

area and clicking 'NGS Info' on the right.

As you can see, once this player's grade

had settled down it was fairly stable,

fluctuating up and down between 57%

and 60%. This is completely natural, so

don't worry too much if your grade is

going down - it might be a normal downswing.

And remember: the further down it

goes, the easier it will be to go back up

again.

One complaint we sometimes hear goes

like this: 'I'm better than so-and-so, but

their grade is 1% higher than mine. This

proves that the NGS doesn't work.' Of

course, the usual answer is that you're not

really better than so-and-so, but if you

genuinely are then this is likely just a

normal fluctuation - 1% is not a significant

amount. Maybe you're on a down-swing,

and they're on an up-swing. In time you'll

both go back towards your true grades and

your pride will be restored.

For more information on how the NGS

works, there is a brief introduction and a

full guide on our website, so please visit

https://www.ebu.co.uk/ngs r

NGS Myths by Michael Clark

NGS TO TAKE ACCOUNT OF TEAM GAMES

THE EBU will soon start processing teams games for the NGS, using the cross-IMPs

that the scoring program calculates. There are some restrictions and software

requirements, so interested clubs should check our website for more information.

click

link

click

link

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