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Spiral scan


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We are going to add some relay and spiral scan into our non relay system.

My knolege of the subject is poor, i read some links explaining it, and i would be happy to read something better if anyone has a link.

I have few questions. (and probebly will have more when ill try it with my partner)

I understand we show controls ,K or A, together, longer suits before shorter, higher ranking from equal lengh.

This mean the Q of the long suit (trump most if the time) will come after all the kings unlike in normal RKCB, am i right about this ?

Do I understand right ,we cant show A single ? how can we handle this problem ?

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hey there

 

I'm very fond of spiral scan, however, its efficiency is closely linked to the amount of information that you have available about responder's shape. I really don't think that this method is worthwhile outside the context of a relay system...

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i think richard is exactly right.. you can play ss over some "standard" openings (such as flannery), but usually it ignores unknown distributions

 

there are many ways to play it... you need to decide the definition of 'top honors'... i use A and K in the two longest suits, the Q thereafter... also, i scan doubletons once and stiffs/voids never

 

i don't have any links, what knowledge i have comes from rosenkrantz books.. but you need to use it after distribution is known, and after a min/max ask (if possible) and control ask

 

the way it works for me is, bid the first step with zero OR all 3 top honors... with one or two of the tops, bid the 2nd step unless you have one or two of the top honors in the 2nd longest suit (or unless you have all 3)

 

the best way would probably be for you to post a hand or three so some examples could be given.. i think you'll love it

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Be careful here... denial cuebids (spiral scan) have specific rules to be effective, and normally require the *full* distribution to be known. The scan rules are

 

1. From longest to shortest.

2. If equal lenght, from higher-ranking to lower ranking.

3. Doubletons are scanned once, singletons are not scanned.

4. Stop scan at first suit that is Jxx or worse, OR AKQ (AK in doubletons).

5. After denial of an honor, you can re-scan 3+ cards suits for jacks.

 

Example. Bidding is at 3NT, and East has shown a 5422 with 4 control pts:

 

KQJxx

QJxx

AK

Jx

 

Asker Responder

4C 4S = top honor in spades, top honor in hearts, all top honors in diams or none

4NT 5C = all top honors or none in clubs

5D 5S = 2nd top honor in spades, no more top honors in hearts

5NT 6H = spade jack, heart jack (remember, with 3 top honors in spades, it would be 4C 4D)

 

It could go on to scan for tens, but jacks are normally where it stops.

 

In a non-relay system, you'd have to think how you can use denial cuebids. Perhaps limit the thing to A or K, and scan all suits only once??

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"The scan rules are

 

1. From longest to shortest.

2. If equal lenght, from higher-ranking to lower ranking.

3. Doubletons are scanned once, singletons are not scanned.

4. Stop scan at first suit that is Jxx or worse, OR AKQ (AK in doubletons).

5. After denial of an honor, you can re-scan 3+ cards suits for jacks.

 

From where did these "rules" come? Point 2 is incorrect, equal length shows H before S and C before D in Moscito, Polish Club, and Tosr.

Where by-passing a step shows AKQ or 0 hons varies and is a matter for partnership agreement.

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Thanks for the responses, especially for the example which like always is the best way to explain things.

I like those rules, i didnt know about the rule to stop on AKQ or AK doubelton, it sounds smart to me.

about the higher ranking first rule, this is the way it was on the links i read, im sure it can played vise versa just as well.

I also didnt know u first ask for control number, good to know.

I plan to play those scans on specific sequences on our polish club (non relay system) after 2h/2s/2nt opening that show premptive 5/5, after our 1sp-2c which is GF relay, and after our precision 2c opening, and 1NT opening.

Im sure the efficienty wont be as good as the best relay structures but i think it will still be fine, i wonder if there are some rules or guidlines about efficientcy, for example how high should we start the scan or else its not worth it (too high)

or is it better to give up on some distribution knowlege (like when we have 5332 or 6322 we dont know the order of the short suits , but when we have sgl we always know where it is) in order to begin the scan on lower level.

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actually the truscott system was first seen (i believe) in rosenkrantz's book bidding on target ... in it, the queen isn't scanned for the first 2 suits but is for the others... given your example of

 

KQJxx

QJxx

AK

Jx

 

with the bid at 3nt and 4c being spiral scan, the bidding would be (according to them):

 

4c : 4h = top spade, no top heart

4s : 4nt = no top diamond or both

5c : 5d = no top club or both

5h : 6h = a top spade honor (known already), the QJ of spades, the QJ of hearts and none or both honors in diamonds or clubs... asker should know which

 

some people do play that a 'top honor' includes the queen, and as rosenkrantz says, these pairs are "slightly more accurate"

 

here's one from a hand i kibbed tonite... this will assume no interference, for illustrative purposes, and i admit very few, if any, easts would look for slam here

 

[hv=d=s&v=e&n=st3h64dj85caqj754&w=saq976ht95da6c982&e=sk852haqdkqt92ckt&s=sj4hkj8732d743c63]399|300|Scoring: IMP[/hv]

 

1NT : 2D - game force

2S : 2NT - 4+ spades, ask

3S : 4C - 5323, control ask

4H : 4S - 4, spiral

5C : 5D - top spade, no top heart

5H : 5S - no top club

6c : 6S - top diamond, placing

 

 

 

 

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About the Q, in the link given before , the rules said, if you have 1 control card (not controls, meaning A is one control card) you include the Q of the first suit, if you have 2 control cards u include the Q of your second suit (but not the Q of ur first suit) etc.

According to this rule, you have 3 control cards, and therefore not include the Q of your second suit on the first scan so over 4c you should bid 4h.

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How much control to assume in hand ?

opening i understand begin with 2 controls.

NT (15-17) i think should start with 3 cnt

after our regular opening we seperate to 11-14/15-17 for the 15-17 maybe we can use 4 cnt and not only 3 , because when having only 3 we can just bid it like 11-14.

Not sure, what is your rule about this ?

Btw i stil,l dont understand what to do with A single, isnt it importent for partner to know about thsi A ?

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Btw i stil,l dont understand what to do with A single, isnt it importent for partner to know about thsi A ?

Its generally assumed that the scanner will be able to infer the presence of a siff Ace...

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Btw i stil,l dont understand what to do with A single, isnt it importent for partner to know about thsi A ?

Its generally assumed that the scanner will be able to infer the presence of a siff Ace...

IC thxs, makes some sense.

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Btw i stil,l dont understand what to do with A single, isnt it importent for partner to know about thsi A ?

Its generally assumed that the scanner will be able to infer the presence of a siff Ace...

If you show your stiff King in response to the control ask then you usually have a good chance of inferring a stiff King.

 

I once had an ambiguity in a crucial decision where if partner's unknown honour was in his short suit then I needed to bail but if it was in his long suit then slam would be back to back - I went with the odds of the honour being in the long suit and was rewarded.

 

Thinking of ambiguities I once had an ambiguity with partner showing AKQ or no honour in two suits. I was void in one and had no way of determining whether partner had the working AKQ or the useless AKQ. No way that is until the fool sitting East ventured a lead directing double.

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for a mini, 10-13, 2 or 3 controls with 4 starting the 'max'

for a weak, 3 with max starting at 4

for a strong, 4 with max starting at 5

 

so 4c : 4s shows 5 on the mini, 5 on the weak, 6 on the strong.. the only 'rule' i like concerning the mini and the weak is possession of the minimum #of controls... partner counts on it

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How much control to assume in hand ?

opening i understand begin with 2 controls.

NT (15-17) i think should start with 3 cnt

after our regular opening we seperate to 11-14/15-17 for the 15-17 maybe we can use 4 cnt and not only 3 , because when having only 3 we can just bid it like 11-14.

Not sure, what is your rule about this ?

Btw i stil,l dont understand what to do with A single, isnt it importent for partner to know about thsi A ?

Points  Controls 

0         0.00
1         0.00
2         0.00
3         0.32
4         0.80
5         1.06
6         1.36
7         1.80
8         2.19
9         2.54
10        2.94
11        3.37
12        3.75
13        4.15
14        4.58
15        4.99
16        5.39
17        5.81
18        6.23
19        6.63
20        7.05
21        7.46
22        7.86
23        8.26
24        8.67
25        9.06
26        9.42
27        9.84
28        10.16
29        10.51
30        10.88
31        11.12
32        11.46
33        11.67
34        11.85
35        11.96
36        12.00
37        12.00

 

A good rule of thumb for 5 hcp up around 30 hcp is

 

expected controls = 0.4 * hcp - 1

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