SD APPLICATION NOTE 3

Copyright © 2000 William B. Ackerman

DISCONNECTED
and
IGNORE

The disconnected concept has not enjoyed a lot of popularity over the last several years. An article in the Zip Coder magazine described it as the “lost concept” . This may be, in part, because people don't always perceive it as having a sound logical basis.

In recent years there has been increased interest in “theoretical” or “computational” approaches to calls and concepts. Calls and concepts that were conceptualized by examples rather than by algorithmic rules haven't fared very well. The disconnected concept may have been a victim of this. It has mostly been conceptualized by examples that people run into on the dance floor.

Common usage has given rise to the principle that, if the call is not a shape- or orientation-changer, you work to spots:


                   4GV  3B^  4BV  3G^  1GV  2B^  1BV  2G^
     
                       BOYS DISCONNECTED swing thru
     
                   4GV  4B^  1BV  3G^  1GV  3B^  2BV  2G^

and the principle that, if both groups are doing disconnected calls, whoever “owned” the center at the start will own it at the end:

                   3G^  4BV  3BV  2G^  4GV  1B^  2B^  1GV
     
           GIRLS DISCONNECTED crossfire WHILE THE BOYS crossfire
     
                           2BV   4G^   3GV   3B^
     
                           1BV   1G^   2GV   4B^

But applications that go beyond these simple principles have not been very popular.

In this note I will try to explain how I (and Sd) believe the concept works.

The callerlab definition says that the designated people do the call as if they had slid together, that is, as though the intervening spots weren't there.


                   4GV  3B^  4BV  3G^  1GV  2B^  1BV  2G^
     
         BOYS DISCONNECTED <anything> -- do the call as if from here:
     
                             3B^  4BV  2B^  1BV

If the call is not a shape-changer, they go back to the same spots. Otherwise, they “stay near the original centers' spots”, and all gaps are closed:

                                                    3B>
      3B>
      3G>                                           2B<
      2B<
      2G<    GIRLS DISCONNECTED lockit  -->   1G^ 2GV 4G^ 3GV
      4G>
      4B>                                           4B>
      1G<
      1B<                                           1B<
     
     
                                          3B>
                                          2B<
     
        -->  (close the gaps) -->   1G^ 2GV 4G^ 3GV
     
                                          4B>
                                          1B<

From the crossfire example, we know that the designees can sometimes all crowd into the center:

                   4B^  3GV  3B^  4GV  2G^  1BV  1G^  2BV
     
                       GIRLS DISCONNECTED crossfire
     
                                  1GV  4G^
                          4B^ 3B^          1BV 2BV
                                  2GV  3G^

But they can't always do so:

                   3GV  4B^  4G^  3BV  1B^  2GV  2BV  1G^
     
                   BOYS DISCONNECTED switch to a diamond
     
                                    4B>
                     3GV  3B^  4G^       2GV  1BV  1G^
                                    2B<

What was the problem in that last example? It was that having all the designees crowd into the center would have pushed the others out. So we have the principle that the designees crowd into the center as much as they can without displacing the others. With crossfire they were able to go into the center because they saved space by stacking themselves 2 people deep.

When the disconnected dancers do a shape- or orientation-changing call that has them maneuver around the others, we are going to restrict their maneuvering to one direction for now.


                   3GV  4B^  4G^  3BV  1B^  2GV  2BV  1G^
     
                            BOYS DISCONNECTED

In this case, all of the maneuvering is done along a left-to-right axis. We paint imaginary stripes on the floor perpendicular to that axis, showing what left-to-right positions are occupied by the designated people.

                        ___       ________       ___
                       |   |     |        |     |   |
                       |   |     |        |     |   |
                       |   |     |        |     |   |
                   3GV |4B^| 4G^ |3BV  1B^| 2GV |2BV| 1G^
                       |   |     |        |     |   |
                       |   |     |        |     |   |
                       |___|     |________|     |___|

After doing the call, the designated people redistribute themselves on the same stripes. They fill the stripes from innermost to outermost, taking whatever space is is provided, and avoiding unnecessarily pushing the inactives outward.

In the current instance of Switch to a Diamond, the centers of the resulting diamond can occupy the center stripe. In fact, the there is room left over—they are only one person wide, and the center stripe is two people wide. So, can the points go into the center also? They would now occupy a width of three, which is greater than the stripe width. This would unnecessarily push the inactives outward. There is room for the diamond points in the outer stripes, so they don't need to occupy the center stripe.

So the center stripe actually gets thinner.


                        ___       ________       ___
                       |   |     |        |     |   |
                       |   |     |        |     |   |
                       |   |     |        |     |   |
                   3GV |4B^| 4G^ |3BV  1B^| 2GV |2BV| 1G^
                       |   |     |        |     |   |
                       |   |     |        |     |   |
                       |___|     |________|     |___|
     
                   BOYS DISCONNECTED switch to a diamond
                          ___       ___       ___
                         |   |     |   |     |   |
                         |   |     |   |     |   |
                         |   |     |4B>|     |   |
                     3GV |3B^| 4G^ |   | 2GV |1BV| 1G^
                         |   |     |2B<|     |   |
                         |   |     |   |     |   |
                         |___|     |___|     |___|

What happens if we do a disconnected flip the diamond from here? The centers of the resulting wave want to occupy the center stripe. But that stripe is only one person wide. We can't have just one of them occupy the center, and the Solomon rule says we can't put half of each in the center. We either put in zero people or two. The rule is that we always put someone in, unless we have run out of people. So, in this case, the two centers go into the center stripe, widening it slightly. This is a case where widening was necessary.

                          ___       ___       ___
                         |   |     |   |     |   |
                         |   |     |   |     |   |
                         |   |     |4B>|     |   |
                     3GV |3B^| 4G^ |   | 2GV |1BV| 1G^
                         |   |     |2B<|     |   |
                         |   |     |   |     |   |
                         |___|     |___|     |___|
     
                    BOYS DISCONNECTED flip the diamond
                        ___       ________       ___
                       |   |     |        |     |   |
                       |   |     |        |     |   |
                       |   |     |        |     |   |
                   3GV |2B^| 4G^ |3BV  1B^| 2GV |4BV| 1G^
                       |   |     |        |     |   |
                       |   |     |        |     |   |
                       |___|     |________|     |___|

If the call had been disconnected drop in, all four people would have have gone into the center stripe. The outer stripe would have been closed.

                          ___       ___       ___
                         |   |     |   |     |   |
                         |   |     |   |     |   |
                         |   |     |4B>|     |   |
                     3GV |3B^| 4G^ |   | 2GV |1BV| 1G^
                         |   |     |2B<|     |   |
                         |   |     |   |     |   |
                         |___|     |___|     |___|
     
                         BOYS DISCONNECTED drop in
                                  ________
                                 |        |
                                 |        |
                                 |3B>  4B>|
                          3GV 4G^|        | 2GV 1G^
                                 |2B<  1B<|
                                 |        |
                                 |________|

Here is another case in which the outer stripes disappear:

                        ___       ________       ___
                       |   |     |        |     |   |
                       |   |     |        |     |   |
                       |   |     |        |     |   |
                   3GV |4B^| 4G^ |3BV  1B^| 2GV |2BV| 1G^
                       |   |     |        |     |   |
                       |   |     |        |     |   |
                       |___|     |________|     |___|
     
                           BOYS DISCONNECTED lockit
                                    ___
                                   |   |
                                   |   |
                                   |4B>|
                                   |1B<|
                           3GV 4G^ |   | 2GV 1G^
                                   |3B>|
                                   |2B<|
                                   |   |
                                   |___|

(The boys' wave actually has no gap across the middle—it is impossible to show it correctly in a text file.)

The designated people don't need to occupy the center stripe:


                   ___       ___            ___       ___
                  |   |     |   |          |   |     |   |
                  |   |     |   |          |   |     |   |
                  |   |     |   |          |   |     |   |
                  |3G^| 4BV |4G^| 3BV  1B^ |2GV| 2B^ |1GV|
                  |   |     |   |          |   |     |   |
                  |   |     |   |          |   |     |   |
                  |___|     |___|          |___|     |___|
     
                       GIRLS DISCONNECTED crossfire
                            ___          ___
                           |   |        |   |
                           |   |        |   |
                           |2G^|        |3GV|
                        4BV|   |3BV  1B^|   |2B^
                           |1G^|        |4GV|
                           |   |        |   |
                           |___|        |___|

A girls disconnected lockit would be illegal from the above formation. All four girls would need to occupy a stripe in the center—the Solomon rule prevents any other solution. But no stripe is available in the center.

There is one more case in which it is necessary to push the inactive people outward. There might not be any more available stripes farther out. When the designated people reach their last stripe, they use it, even if it pushes the inactives outward. New stripes are never created.


                            ___          ___
                           |   |        |   |
                           |   |        |   |
                           |2G^|        |3GV|
                        4BV|   |3BV  1B^|   |2B^
                           |1G^|        |4GV|
                           |   |        |   |
                           |___|        |___|
     
                       GIRLS DISCONNECTED peel off
                        ________            ________
                       |        |          |        |
                       |        |          |        |
                       |        |          |        |
                   4BV |2GV  1GV| 3BV  1B^ |3G^  4G^| 2B^
                       |        |          |        |
                       |        |          |        |
                       |________|          |________|

If there is a stripe at the outside of the setup, it is filled as necessary.

                         ___                    ___
                        |   |                  |   |
                        |   |                  |   |
                        |3B^|                  |4BV|
                        |   |4G^  1G^  3GV  2GV|   |
                        |2B^|                  |1BV|
                        |   |                  |   |
                        |___|                  |___|
     
                         BOYS DISCONNECTED peel off
                   ________                      ________
                  |        |                    |        |
                  |        |                    |        |
                  |3BV  2BV| 4G^  1G^  3GV  2GV |4B^  1B^|
                  |        |                    |        |
                  |________|                    |________|

If the last stripe is the one in the center, it gets filled appropriately, however far the inactives have to be pushed out.

                                  2GV  3G^
                          2BV 1BV          3B^ 4B^
                                  1GV  4G^
     
                          GIRLS DISCONNECTED peel off
     
                   2BV  1BV  1G^  2G^  4GV  3GV  3B^  4B^

(But this isn't a real instance of disconnected.)

Here are some examples showing 6 active people:


                         3B^                    4BV
                             2GV  3GV  1G^  4G^
                         2B^                    1BV
     
              IGNORE THE SIDE GIRLS, TRIANGLE peel and trail
     
                   3BV  3G^  2GV  2BV  4B^  4G^  1GV  1B^




                                  1GV  2G^
                          1B^ 4B^          2BV 3BV
                                  4GV  3G^
     
                IGNORE THE SIDE BOYS, TRIANGLE peel and trail
     
                   1G^  1BV  4B^  4G^  2GV  2BV  3B^  3GV

The ignore concept is the way to make 6 people work disconnected. Naming them explicitly (“heads and side girls”) is unwieldy, and is not supported by Sd.

In both of these cases, the designated people started in a center stripe two people wide, and the outermost stripes.


                          4B>       4G<       1G>
                               3B^       1BV
                          3G<       2G>       2B<
     
           IGNORE THE HEAD BOYS, THOSE FACING START, pass the ocean
     
                   3G^  4GV  3B^  2B^  4BV  1BV  2G^  1GV

In this case, the designated people started in a center stripe one person wide, and the outermost stripes. They must push the inactive people out slightly.

When The Stripes Aren't Simple

Up to this point, we have been assuming that the designated people are spread out only along one axis, so that stripes can be used, and that they are totally compressed along the other axis. I know of no comprehensive theory that can describe the situation in which the spreading out can be arbitrary. Fortunately, it appears that, for setups with only 8 people, only a few cases can arise.

It seems that, when the selected people are disconnected along both axes, they either work to spots (the obvious easy case) or they work in a simple way around whoever is causing them to be disconnected. Gaps are closed as needed.

About the only straightforward and sensible case of this is is a call done by the points of an hourglass.


                                 4G>   1G>
                                    4B>
                              3B^         1BV
                                    2B<
                                 3G<   2G<
     
                        GIRLS DISCONNECTED peel off
     
                                    1G<
     
                                    4G<
     
                                    4B>
                              3B^         1BV
                                    2B<
     
                                    2G>
     
                                    3G>

(A girls concentric peel off, or just girls peel off, would have gotten the same result.)

                                 4G>   1G>
                                    4B>
                              3B^         1BV
                                    2B<
                                 3G<   2G<
     
                      GIRLS DISCONNECTED follow thru
     
                                    4B>
                     3B^  3G^  2G^       4GV  1GV  1BV
                                    2B<

(A girls concentric follow thru would have moved the girls outside of the head boys.)

Here are some cases in which a diamond is formed. Notice that the girls work only around the side boys. They are inside of the head boys.


                                 4G>   1G>
                                    4B>
                              3B^         1BV
                                    2B<
                                 3G<   2G<
     
                    GIRLS DISCONNECTED peel to a diamond
     
                                    1G<
                                    4B>
                          3B^ 2G^         4GV 1BV
                                    2B<
                                    3G>




                                 4G>   1G>
                                    4B>
                              3B^         1BV
                                    2B<
                                 3G<   2G<
     
                      GIRLS DISCONNECTED 1/2 circulate
     
                                    4G>
                                    4B>
                          3B^ 3G^         1GV 1BV
                                    2B<
                                    2G<

Everyone Disconnected

The disconnected concept is usually not used with phantoms. However, an interesting extension was recently introduced in the Zip Coder article mentioned previously. This is everyone disconnected. (Sd also lets you say all disconnected.) In this case, the “stripes” must be able to distinguish the matrix spots occupied by live dancers and the unoccupied spots. The live dancers work to the live stripes according to the usual rules.

                     3B^    .    1G^   2GV    .    4BV
     
                     2B^    .    4G^   3GV    .    1BV
     
                      EVERYONE DISCONNECTED mini busy
     
                            .    3BV   1GV    .
     
                     2G^    .    2BV   4B^    .    4GV
     
                            .    3G^   1B^    .

The “Ignore” Concept

This concept, like disconnected, has suffered from a lack of sound theoretical understanding. The callerlab definition says to do the call as though the other spots weren't there. That's a lot like disconnected.

I believe that, except for “space invader” calls, the ignore concept should be treated as disconnected for the other people. The same rules about working to spots, or filling stripes and closing gaps, should apply. Hence we have:


                   4BV  4G^  3GV  3BV  1B^  1G^  2GV  2B^
     
                  IGNORE THE HEAD GIRLS, GRAND swing thru
     
                   3BV  4B^  3GV  2GV  4G^  1G^  2BV  1B^




                           3B^   2G^   4BV   1GV
     
                           3G^   2B^   4GV   1BV
     
                   IGNORE THE SIDE BOYS, in roll circulate
     
                           3G^   3BV   4BV   2GV
     
                           4G^   2B^   1B^   1GV




                         4BV                    2G^
                             3B^  3G^  1GV  1BV
                         4GV                    2B^
     
                IGNORE THE HEAD BOYS, TRIANGLE, peel and trail
     
                   4G^  3GV  3B^  4B^  2BV  1BV  1G^  2GV

When the call is a space-invader (e.g. press or truck), the ignore concept can't mean to work around the others as though they weren't there. Space-invading calls work in absolute position.

When some people are ignored for a space-invading call, they simply don't do it. The others do the call, using the usual absolute definition of where they go.


                           4B>   4G>   1B>   1G>
     
                           3G<   3B<   2G<   2B<
     
                    IGNORE THE SIDE BOYS, press ahead
     
                      .    4B>    .    4G>   1B>   1G>
     
                     3G<   3B<   2G<    .    2B<    .