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Bridge Bulletin Bidding Box scoring

#1 User is offline   antonylee 

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Posted 2015-February-02, 00:30

The last issue of the Bridge Bulletin's bidding contest featured the following hand:

(East deals)
Both Easts opened; one pair reached 4 after a 1 opening and the other 6 after a 1 opening and what seems to be a misunderstanding. As it turns out, 6 was the winning spot and is much better than 6.

However, I wonder why 6 was awarded 12 (on a 12 top) when it is still "only" a 68% contract (3-2 clubs). Giving 12 to a contract assumes that it will be rarely bid, but in that case 6 gets a zero 30% of the times.

Thoughts?
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#2 User is offline   Mbodell 

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Posted 2015-February-02, 00:36

I think it should be getting a 9 or 10 not 12. You can bump it up a little for wanting to reward the perceived best spot as well as silent opponents making extreme shapes less likely.
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#3 User is offline   rhm 

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Posted 2015-February-02, 03:48

That depends how you score in a bidding challenge.

Does the score reflect the matchpoint expectancy you can expect in a strong field or does the top score go to the most desirable contract irrespective of whether it will always make in practice or not?

If you use the former then it is impossible to get more than a certain percentage of all the points available in a bidding challenge, even if you reach the best spot on each deal.
You are at the mercy of the layout of the cards solely dealt to your opponents, which you usually can not be detected during the bidding unless opponents take part in the bidding.

I think the latter is more sensible.
This is the policy of the Bridge World, which I believe invented this challenge. If you reach the best contract on each deal of ten in their bidding challenge you will get a maximum score of 100 points.
On most deals the best contract will score ten points, but if one is particularly difficult to reach it can get 11 points but then there is another deal in the set where the top score will be rewarded 9 points.

So I also would award a top score to 6.

Rainer Herrmann.
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#4 User is offline   antonylee 

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Posted 2015-February-02, 04:29

But the Bidding Box often has top scores of less than 12 (in fact, this month this is the only problem where the top contract scores 12). Also, it is obviously more important to find the best contract when alternative contracts have little play (e.g. problem 5, where you must find 3N instead of 4S with AKQxxx K xxx Ax opposite xx Axxx Jxxxx xx, but 3N only scores 10, probably because the scorer expected more pairs to reach that contract?) rather than here where you'll get a (shared) zero 30% of the times for bidding the top contract.
I agree with Mbodell's suggestion for 9 or 10.
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#5 User is offline   barmar 

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Posted 2015-February-02, 09:21

I've noticed that in general Challenge the Champs and Bidding Box don't adjust down very much for contracts that depend on normal breaks. They'll reduce the score for a contract that needs a finesse, but that's about it.

#6 User is offline   GreenMan 

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Posted 2015-February-04, 10:22

They may have taken into account a greater degree of difficulty from there being another reasonable contract (6) that must be avoided. It's not just "Find the difficult-to-bid slam," it's "Find the difficult-to-bid slam and don't bid the not-as-difficult slam."

It seems like a bit of a trick hand to me, but what can you do.
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#7 User is offline   barmar 

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Posted 2015-February-04, 19:04

The general idea is that you're being challenged to bid like a champion. Experts aren't going to avoid a slam just because it needs a 3-2 trump break, so the bidding contests don't want to reward contestants who do.

#8 User is offline   Phil 

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Posted 2015-February-04, 23:15

I saw this hand too and didn't think 6 was that bad - duck a club and ruff three hearts in hand - 3S + 3 ruffs + 2D + 4C.

Two 3-2 splits is (about) 50%. 6 needs 3-2 clubs.

I'm guessing when both slams make 6 gets an 11 and 6 gets a 9.

When 6 makes and 6 goes down its probably an 11 vs 1.

When both go down, they both get 2's.

So 6 = (.5 x 11) + (.18 x 1) + (.32 x 2) = EV of ~6 or 6.5

6 = (.68 * 9) + (.32 *2) = EV of 6.5 or 7'

Seems kind of close?
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#9 User is offline   nige1 

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Posted 2015-February-05, 06:36

Agree with rhm and Phil. In 6, you can win the lead with K, ruff a , duck a , win the exit with A, ruff a , cross to J, ruff a , and take the remaining tricks with AQ and AKxx when both black suits break 3-2.
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