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Parity Cue Bids

#1 User is offline   Cascade 

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Posted 2019-October-08, 15:06

I have seen lots of mention of awm's description of parity cue bids but try as I might I cannot find his original posts on the topic by searching. Does anyone with better search skills or more knowledge of this than I have links to his orginal post(s).

Thanks
Wayne Burrows

I believe that the USA currently hold only the World Championship For People Who Still Bid Like Your Auntie Gladys - dburn
dunno how to play 4 card majors - JLOGIC
True but I know Standard American and what better reason could I have for playing Precision? - Hideous Hog
Bidding is an estimation of probabilities SJ Simon

#2 User is offline   rbforster 

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Posted 2019-October-08, 20:37

Here’s the basics. In a relay sequence, after asking for AKQ=321 points,

https://bridgewithda...IMprecision.pdf

Quote

Once RPs are shown we show parity of top three honors in each suit by halting if even parity and skipping onwards if odd parity. All suits will be scanned (excluding voids but including singletons) in order of length in describer’s hand with higher suits first in case of ties. In the case where RPs are shown with the first step (which has two possibilties), we stop with the minimum, and zoom into answering parity.
After showing all parities, we next shows the number of RP in the first suit with only one honor, if such suit exist, and stop if odd (A or Q) or skip a step if even (K). We may zoom into answering this, but we never zoom beyond this ask.
After answering the parity question, we next ask for jacks.


Also try searching just this forum (Non-Natural) for the word “parity”. You should see a collection of posts PCB## from 2017 where different hands are bid, as well as another set on Auction Termination from 2013 with examples. There are only 2-3 pages of threads in total.
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#3 User is offline   Cascade 

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Posted 2019-October-09, 03:55

View Postrbforster, on 2019-October-08, 20:37, said:

After showing all parities, we next shows the number of RP in the first suit with only one honor, if such suit exist, and stop if odd (A or Q) or skip a step if even (K).


Thanks.

What happens if there is no such suit?

So I finish the parity showing responses at say 4H and partner relays with 4S, now 4NT says my first suit with one honour has A or Q and 5C says it is even. Do I have to bid 5D to say there is no such suit?
Wayne Burrows

I believe that the USA currently hold only the World Championship For People Who Still Bid Like Your Auntie Gladys - dburn
dunno how to play 4 card majors - JLOGIC
True but I know Standard American and what better reason could I have for playing Precision? - Hideous Hog
Bidding is an estimation of probabilities SJ Simon

#4 User is offline   foobar 

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Posted 2019-October-09, 10:48

View PostCascade, on 2019-October-09, 03:55, said:

Thanks.

What happens if there is no such suit?

So I finish the parity showing responses at say 4H and partner relays with 4S, now 4NT says my first suit with one honour has A or Q and 5C says it is even. Do I have to bid 5D to say there is no such suit?

The response showing the K-parity is tacked on to the last step in the parity scan. Say that we scanned a 5=4=2=2 shape and parity happened to even-even-even-even, with 4H as the terminal step. Since all suits have even parity, there's no presumptive candidate for the first suit with odd parity, so we stop at 4H with AQ in spades (or nothing) or bid 4S with the AK / KQ (longest+highest suit in the scan order). Also, note that when scanning singletons, we stop with a stiff AK(Q) and skip without (the latter is more likely and the decision on whether to skip the stiff Q depends on your QP evaluation methods).

BTW, awm had a recent minor tweak to address the problem of identifying KQ combinations in two suits with even parity, but am not completely sure of the exact mechanism.
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#5 User is offline   straube 

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Posted 2019-October-09, 20:49

I think awm doesn’t show king parity with all even (Atul and I do) and I think he treats a singleton honor as odd (we treat as even for the reason Atul said).

They’ve actually stopped using the king parity question altogether. Instead, they ask to clarify which longest/ranking suits have the KQ in one and zero in the other whenever that possibility exists. Failing that, they ask a different question when K by itself is in one suit and the Q by itself is in another (again focusing on the longer/ranking suits). If neither question applies, the question doesn’t exist.

I think they’re trying to solve the “marriage problem” But Atul and I found using that addendum very difficult. We switched back to king parity.
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#6 User is offline   Cascade 

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Posted 2019-October-11, 22:14

View Poststraube, on 2019-October-09, 20:49, said:

I think awm doesn’t show king parity with all even (Atul and I do) and I think he treats a singleton honor as odd (we treat as even for the reason Atul said).

They’ve actually stopped using the king parity question altogether. Instead, they ask to clarify which longest/ranking suits have the KQ in one and zero in the other whenever that possibility exists. Failing that, they ask a different question when K by itself is in one suit and the Q by itself is in another (again focusing on the longer/ranking suits). If neither question applies, the question doesn’t exist.

I think they’re trying to solve the “marriage problem” But Atul and I found using that addendum very difficult. We switched back to king parity.


After a strong club, what is your base QP for responder? (And what is your minimum strength for a positive response and for opener's 1?
Wayne Burrows

I believe that the USA currently hold only the World Championship For People Who Still Bid Like Your Auntie Gladys - dburn
dunno how to play 4 card majors - JLOGIC
True but I know Standard American and what better reason could I have for playing Precision? - Hideous Hog
Bidding is an estimation of probabilities SJ Simon

#7 User is offline   straube 

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Posted 2019-October-12, 07:48

My understanding of IMprecision is that its 1C base is 9 (and they combine 9 and 10 with the first step and separate with the next bid) but they use semipositives that range from 2-6 QPs (2-3 are combined similarly as the first step). They don’t have positives, so opener’s hand is relayed or they use their Opening NT system if opener rebids 1N.

It’s a very strong system. In a word, Adam and Sieong figured out an extremely useful reason to break relay...which is to suggest part scores and investigate/invite game. Another way of putting that is that if you play a relay system such as standard symmetric and find yourself rebidding 1S after a 1H response 80+ % of the time, you know you’re losing sequences.

Adam might explain the rationale differently, emphasizing how the club responses get distributional information quickly for the appropriately 5-11 hcp range of responding hands.
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#8 User is offline   awm 

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Posted 2019-October-12, 08:15

A game forcing positive for a 16+ club would start at 4RP. We generally compute this by taking HCP for a balanced hand, subtracting two (jacks and or shape upgrades) and working out the lowest RP possibility. This gives:

5+ HCP (semi positive) for 2+ RP
9+ HCP (GF positive) for 4+ RP
11+ HCP (opening) for 5+ RP
17+ HCP (strong club) for 9+ RP (have to start using Kings here because there are only four queens; lowest RP way to get to 15 is 3K+3Q)

It’s possible to come up with hands satisfying the HCP without the RP of course, but they tend to be very “quacky” hands that may be worth downgrading. There are also hands that get upgraded (we open lots of unbal tens and some nines) but usually it’s bad to upgrade hands without controls so these upgrades tend to be higher in the RP front anyway.

All this said, Straube is correct that we do not generally play GF positive responses to 1C in the current incarnation of our system.
Adam W. Meyerson
a.k.a. Appeal Without Merit
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#9 User is offline   straube 

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Posted 2019-October-12, 11:45

I forgot you have GF single-suited club responses.
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