Parity Cue Bids
#1
Posted 2019-October-08, 15:06
Thanks
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
Posted 2019-October-08, 20:37
https://bridgewithda...IMprecision.pdf
Quote
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.
#3
Posted 2019-October-09, 03:55
rbforster, on 2019-October-08, 20:37, 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?
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
Posted 2019-October-09, 10:48
Cascade, on 2019-October-09, 03:55, said:
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.
#5
Posted 2019-October-09, 20:49
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.
#6
Posted 2019-October-11, 22:14
straube, on 2019-October-09, 20:49, 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♣?
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
Posted 2019-October-12, 07:48
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.
#8
Posted 2019-October-12, 08:15
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.
a.k.a. Appeal Without Merit
#10
Posted 2019-November-19, 22:05
Responder to an IMPrecision-style 1♣ held
AJxx A AJxxxxx x
Teller showed 5-2-2-4 with 11RP, then stopped four times to show an even number of honours in all four suits. Teller clearly has to have the CAK and KQ + KQ.
How can asker find out which? Even if using the refinements played by Sam and Adam -- If there is a pair of suits where one has KQ and the other has none, the first such pairing (length order, followed by high to low) is picked; stop if first suit has KQ, skip if second suit has KQ -- all asker finds out is that teller has the SKQ. How does asker find out which of the red suits is xx and which KQ?
What do experienced PCB users do?
Are cases like this exceptional it seems they arise only when asker has three suits with 0-1 honour? Are they just the equivalent of problem hands for other methods of denial cue bidding?
#11
Posted 2019-November-20, 00:12
We run into marriage problems, too, but not often enough for me to stop thinking PCB is a great tool. Virtually all of our relay auctions proceed through it. That's partly, however, because I wanted us to master it before considering adjuncts to PCB. Also, AQ pairs are also (rarely) a problem.
PCB is primarily 5 questions, odd/even for each suit and an additional clue to disambiguate. We could add another question to help further disambiguate but at the cost of getting too high and delaying a jack ask. Not sure if the marriage problem is frequent enough to merit adding a 6th question. And would two final clues would we choose?
Wondering, however, if asker could break relay to ask clarification. Say teller bids 4S to show even spades. Asker foresees a marriage problem and bids 5C to ask if this even is 0 or if it is 2. Of course you'd have to have preset rules about when asker could skip suits to ask vs skip suits to suggest a contract. Conveniently, teller stops on even which is the point where asker could consider a relay break.
#12
Posted 2019-November-21, 17:42
DinDIP, on 2019-November-19, 22:05, said:
Responder to an IMPrecision-style 1♣ held
AJxx A AJxxxxx x
Teller showed 5-2-2-4 with 11RP, then stopped four times to show an even number of honours in all four suits. Teller clearly has to have the CAK and KQ + KQ.
How can asker find out which? Even if using the refinements played by Sam and Adam -- If there is a pair of suits where one has KQ and the other has none, the first such pairing (length order, followed by high to low) is picked; stop if first suit has KQ, skip if second suit has KQ -- all asker finds out is that teller has the SKQ. How does asker find out which of the red suits is xx and which KQ?
What do experienced PCB users do?
Are cases like this exceptional it seems they arise only when asker has three suits with 0-1 honour? Are they just the equivalent of problem hands for other methods of denial cue bidding?
Can you please post some hands that were especially problematic? This should be general interest to this thread and we might get clarity on the refinements if Adam or Sam chime in. FWIW, having switched to PCB from DCB, it's definitely seems superior AFAICT, but it'll be good to have an objective discussion.
#13
Posted 2019-November-22, 00:44
If we define 5C as an ask, what should it ask? Like any of the following?
1) stop with 0, continue PCB with 2
2) stop with 2, continue PCB with 0
3) stop with 0, skip with 2, asker will then p/c
4) stop with 2, skip with 0, asker will then p/c
5) skip your next suit because asker has the AKQ
6) give K parity
#14
Posted 2019-November-22, 12:17
straube, on 2019-November-22, 00:44, said:
Is this a truly generalized situation? For example, what if the PCB for the longest suit (♣s), and relay captain was looking for AKQ♣ to determine whether to bid 6♣?
#15
Posted 2019-November-22, 13:14
OTOH, you could certainly make the relay break ask anything. Could ask about the longest suit (for example) even if it's odd.
Basically, I think we have a free opportunity here and am looking for the best question to ask.
#16
Posted 2019-November-23, 04:09
straube, on 2019-November-22, 13:14, said:
OTOH, you could certainly make the relay break ask anything. Could ask about the longest suit (for example) even if it's odd.
Basically, I think we have a free opportunity here and am looking for the best question to ask.
1. If relayer was looking for cAKQ and you showed even then relayer knows you don't have AKQ so might now want to play in 5C.
2. More generally we want to know what the best question to ask is at each stage of the relay. I think there is some room for some work here to determine what are on average the best discriminators for slam and possibly reframe our questions.
3. It might be possible to always have two questions to ask, or conditionally to have two questions to ask based on what information you have received. This would come at the cost of a sign off bid.
Kerr and Jones had this conditional idea in some sequences. They had a rule that if partner responds at the four level showing five or more controls then as well as the normal one step relay, the relayer could bid 4NT asking for queens. The idea is that partner knows all of the controls often after such a response and instead of having to go through suits twice to find the queens can ask immediately for queens - whether none, one, or two controls are missing.
... 4♦ five controls
4♥ - keep relaying.
4NT - show me queens, their responses were 5♣ none, otherwise cue the queen with 5NT showing the club queen and 6♣ two queens.
They used the same principle with a 5NT bid (non-jump and maybe a jump over 4♠ - I don't know).
This idea could be extended to other situations, where you have two asks and whatever your style of cue bids - denial or parity or whatever.
I have had situations where the slave hand has gone so many steps that they must have what I want. But what say in the same situation I still need a key jack or something. If the bidding is low enough then it is all but impossible that I want to sign off below slam. Therefore we are free to have multiple asking bids up to at least 5NT under those conditions.
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
#17
Posted 2019-November-23, 06:15
Any thoughts here, Adam? What would you test if anything?
#18
Posted 2019-December-14, 18:23
1. Teller held AJ9xxx AKQx K Kx and showed 12RP (we count kingletons as 1RP and stiff Qs as 0) and an odd parity in each suit. Teller's last bid was 5♠. Asker had xx xxxx Axxx AQx and now knew slam was worth bidding in the major in which teller had AKQ. However, the 5N marriage ask elicited a 6♦ response, and now we could no longer play in 6♥.
2. Teller held Axx AKQJxx Q Axx and showed 12RP and an odd parity in H, S and C, and no honour in D (we stop to show singleton honours). Teller then zoomed to answer the marriage question, but this was 5♣. Not a problem on the actual hand but asker, who again had no honours in either major, would have wanted to stop in 5♥ if teller had AKQ Axxxxx Q Axx.
Were these just random luck? I note that: they only occurred because asker had no honour in two suits; and if the first auction had been one step higher then stopping with the marriage in the longer/higher-ranking suit would work better. Or is redgrover right and we should switch the responses?