Skip Scan or Spiral Scan

[Sonny S]

How do we proceed when the relayer know the distribution of partners hand?

Can you explain how "Skip Scan" or "Spiral Scan" work?

[Finch]

The only one I know is spiral scan. I think there is bound to me more than one version of this, because there is more than version of any of these methods... but this is the one I play:

 

- "key" cards are defined in order. The order depends on whose shape has been determined vs. who is responding to the spiral ask. Usually the replier is the hand which has defined its shape, but if both hands have shown their shape, it is the asker's shape that is considered most important.

 

The order is:

 

- Number of aces (03/14/2) (with 1-4 aces you stop there, with 2 you continue)

- Queen of trumps

- King of longest side suit

- King of second longest side suit

- [King of third suit if it's not a singleton]

- Queen of longest side suit

- Queen of second longest side suit

- [singleton King in third suit]

- Jack of trumps

 

you can keep going, but have usually run out of room by then.

 

Where two suits are of equal length, the higher comes first.

Where suits are of unknown length, they are in the order spades-hearts-diamonds-clubs

 

The asker bids step 1 to ask about the first card on the list, step 2 to ask about the second. The responder bids the number of steps stopping at the first card he doesn't have.

 

We also use the first ask as a range ask, but I think that's generally quite rare.

 

I only play spiral in a small number of forcing raise auctions, but here's a made up example just to show how it works:

 

AKxxx

QJxx

Ax

Qx

 

QJxx

AKxx

Kxx

Ax

 

North deals, matchpoints

After some sort of relay auction, South knows that North has a 5422 distribution and has indicated that spades are trumps, and is at the 3NT level (say). Starting with South's next call:

 

4C (first spiral ask)

4D (0/3)

 

4H from responder would ask about the SQ, 4S would be a sign-off, 4NT would ask about the K of the side suit, 5C about the DK

 

5D (CK ask)

5H (no CK)

 

5S would be a sign-off, but responder is probably happy enough to try for slam

 

5NT (HQ ask)

6H (HQ, DQ, no CQ)

 

7H (good enough)

 

The point about asking for the CK in the middle is that we might have had 13 top tricks. Playing IMPs, you might go straight to the HQ ask after the keycards, because that's all you really need for a grand in hearts.

[Gerben42]

Another one is denial cuebids. Example:

[hv=w=saqjhj83dakq83ck4&e=s4ha92dt972caqjt8]266|100|[/hv]

 

1♣ (1) 2♣ (3)

2♦ (2) 2♥ (4)

2♠ (2) 2NT (5)

3♣ (2) 3♦ (6)

3♥ (2) 4♣ (7)

4♦ (2) 4♠ (8)

4NT (2) 5♥ (9)

5♠ (2) 5NT (10)

6♣ (2) 6♥ (11)

7♦

 

(1) strong ♣

(2) relay

(3) 5+♣

(4) 4♦ longer ♣

(5) ♠ shortness

(6) 1=3=4=5

(7) 4 controls

(8) top ♣ honor, no top ♦ honor

(9) ♥ honor, second ♣ honor, no ♦J

(10) no second ♥ honor

(11) ♣J no ♥J

 

After 3♦ shows the shape, the next relay asks for the number of controls (A=2 K=1)

The next relay, here 4♦, starts denial cuebids.

 

Responder shows top honors, longer suits first. You start with Aces and Kings, and if you have N cards worth of Aces and Kings (here N=2, 2 Aces), after showing N-1 cards you start showing Queens too. If you have AKQ or doubleton AK you skip this suit.

Doubleton suits are reviewed only once, singletons are ignored.

 

Here (8) showed control in the first suit (♣) and none in the second (♦). The ♣ must be either Ace or King, then we have reached N-1 so we will now also count Queens, so this means no ♦A, K or Q (or all 3).

 

(9) Next the top honor in ♥ is shown and the 2nd honor in ♣ (this is either AK, AQ or KQ). As ♦ is denied again, this denies the ♦J as AKQ have already been denied.

 

(10) ♥ are next. Since we don't have either K or Q in ♥, we deny ♥.

 

(11) The final ask we are back in ♣ and show the J. This cannot be the third top honor from AKQ since AKQ will start by DENYING an honor. Since ♦ are done ♥ is next. We don't have the next card there (the J) so we deny ♥.

 

This ends the denial cuebidding and opener places the contract in 7♦.

[Gerben42]

Frances' example will go like this (North deals, MP)

 

1♣ (1) 1NT (3)

2♣ (2) 2♥ (4)

2♠ (2) 3♣ (5)

3♦ (2) 4♦ (6)

4♥ (2) 4NT (7)

5♣ (2) 6♣ (8)

7♥ (9)

 

(1) strong ♣

(2) relay

(3) balanced

(4) 4 - 4 red or black

(5) 4=4=3=2

(6) 6 controls

Two suits of equal length start low. Here N = 4

(7) ♥ honor no ♠ honor

(8) Top honors in ♦, ♣, ♥ and ♠, no ♥J.

 

(9)

Opener now counts: 2 control cards in ♥ must be AK (3 controls).

Partner must have A+ K (3 Kings is impossible since I have ♠K) in other suits so N = 4. Since I have ♦A partner has ♣A and ♦K. Since N = 4 the honor shown in the second round of ♠ is ♠Q.

 

Conclusion: Partner has

♠ Qxxx

♥ AKxx

♦ Kxx

♣ Ax

 

Enough to bid 7♥!

[Finch]

The point about asking for the CK in the middle is that we might have had 13 top tricks. Playing IMPs, you might go straight to the HQ ask after the keycards, because that's all you really need for a grand in hearts.

Not relevant to the original topic, but untrue. With

AKxxx

Q10xx

Ax

Kx

 

opposite

 

QJxx

AKxx

Kx

Axx

 

you do of course want to be in 7NT at all forms of scoring.

[benlessard]

You play that the next bid is always a relay ? So 6clubs isnt to play ?

 

 

1♣ (1) 2♣ (3)

2♦ (2) 2♥ (4)

2♠ (2) 2NT (5)

3♣ (2) 3♦ (6)

3♥ (2) 4♣ (7)

4♦ (2) 4♠ (8)

4NT (2) 5♥ (9)

5♠ (2) 5NT (10)

6♣ (2) 6♥ (11)

7♦

 

 

so after 5♥ is you want to stop in 6c you have to bid it now...

 

and after 4d you cannot skip to bypass cards you have in your hands ?

 

 

Seems a bit akward but i have almost no practice with denials.

 

 

 

Also does a stiff k of s count as a control if so the hand could be

 

 

K

kxx

xxxx

aqjxx

 

 

 

Ben

[hrothgar]

You play that the next bid is always a relay ?

So 6clubs isnt to play ?

Like any part of a relay system, Spiral Scan requires explicit rules regarding which bids are forcing and non-forcing. I've seen two different style of spiral scan used:

 

Style 1: Next step is forcing. Breaks are non-forcing

 

Style 2: The trump suit is set before denial cue bidding starts. Bidding the trump suit (at any level) is non-forcing. Step = denial cue bid. Relay breaks are used to skip suits in the scanning sequence.

 

There are pluses and minuses to either approach. Style 1 seems more popular these days.

 

Its certainly possible to add complexity to the system. For example, you can add special agreements that various six level bids are non-forcing. However, these should be treated as exceptions and not assumed to be in any way standard.

[Gerben42]

Right you can add some complexities, for example that you insert singleton Kings somewhere. If you agree for example that after you scanned both suits twice, before going to Jacks in long suits you include singleton Kings, that's very playable.

[joshs]

You play that the next bid is always a relay ?

So 6clubs isnt to play ?

Like any part of a relay system, Spiral Scan requires explicit rules regarding which bids are forcing and non-forcing. I've seen two different style of spiral scan used:

 

Style 1: Next step is forcing. Breaks are non-forcing

 

Style 2: The trump suit is set before denial cue bidding starts. Bidding the trump suit (at any level) is non-forcing. Step = denial cue bid. Relay breaks are used to skip suits in the scanning sequence.

 

There are pluses and minuses to either approach. Style 1 seems more popular these days.

 

Its certainly possible to add complexity to the system. For example, you can add special agreements that various six level bids are non-forcing. However, these should be treated as exceptions and not assumed to be in any way standard.

Well generally, if you play spiral scan as part of a natural system, you have already set trumps and can use breaks to ask other questions. If you play relay and you haven't set trumps, you don't have much choice.

 

I do play spiral scan in one natural (or Supernatural...) system, although I don't like it that much. I prefer grand slam auctions to be co-operative when both players know something about each others hands.

 

Actually here is an interesting treatment which John Fout mentioned to me. Super kickback. After a 5 level cuebidding auction you can bid one over the agreed suit as keycard. That way you have a co-operative auction showing or denying extras and having 2 levels to show A's K's and maybe even Q's in partner's suit (if thats your style) and then use keycard as a doublecheck that you have everything you need for 7.

[Sonny S]

In a new partnership we have discussed to try controls ask and ambiguous denial cue-bids, like the schema below.

Have you tried something like that? Maybe denial cue bids with two meanings are a little risky? Any comment is welcome.

______________________________________________________________________________________________

 

Control ask and Denial Cue-bids

After we know distribution 1st relay is control ask:

If 6-9 hpc: 0-1, 2, 3 or 4

If 10+ hpc: 0-2, 3, 4, etc

If 15+ hpc: 0-3, 4, 5, etc

If 20+ hpc: 0-4, 5, 6, etc

 

Don’t include a singleton K when showing controls.

 

After control ask next relay start denial cue-bids. On the first ask (“Scan”) you look for A/K or AQ/AK in longest suit. If you don’t have A or K or if you have AQ or EK you bid the next step to show this.

 

1st step:

A: Denies A or K in longest suit or in higher-ranking suit

B: Shows AK or AQ

 

2nd step:

A: Denies A or K in second suit

B: Shows AK or AQ

 

Etc.

 

Next step is forcing. Breaks are non-forcing.

3N is, of course, never relays ask.