Writing an A-B Rallye

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The main difference between writing an A-B rallye and writing a coursemarker rallye is that an A-B rallye must work with only the route instructions and existing signs/landmarks. With a CM rallye, rallyemasters can post additional CMs to get rallyists back on course if they catch only part of a gimmick. With an A-B rallye, rallyemasters cannot use CMs or Supps to get confused rallyists back on course.

It is still possible for multiple gimmicks to interact in an A-B rallye, but they need to do so without creating too many possible options for the rallyists. Each RI can handle only 2 (or sometimes 3) alternatives. If multiple gimmicks interact to create several options for the rallyists, then you're going to need a few RIs to get everyone back on course. Writing (and scoring!) those RIs is going to be more complicated and difficult.



There are four main types of Route Instruction in an A-B rallye:

Same Location 
Both parts refer to the same action(s), performed at the same location(s), and the rallyist must determine whether each part is valid.
Same Route 
Both parts occur along the same route, but not at the same location, and the rallyist must determine whether the first part is valid.
Supp Style 
One part occurs beyond a turn for a gimmick (typically using Observe or CS), and the other part gets rallyists back on route immediately (e.g., "U at Smith, R 1st Opp"), the way Supp instructions do in CM rallyes.
The parts occur along different routes, with the two routes eventually rejoining.

Simple gimmicks based on instructions that are invalid per the GIs (e.g., misspelled street names or words that "do not exist on signs") typically use either the Same Location or Same Route type of RI.

More complex gimmicks (especially those that have rallyists turn on specific streets) cannot use the Same Location type of RI. When they use the Same Route type of RI, they tend to be more obvious because one of the parts will refer to the same turn as the higher-precedence gimmick. Rallyists need to realize that they should do the turn for the higher-precedence gimmick, rather than for the RI.

Using a Supp Style type of RI makes the gimmick less obvious, because those who do not get the gimmick will not encounter the landmark for the part that acts like a Supp. However, it is still relatively easy for experienced rallyists with maps to figure out where they would need to turn to do the part that acts like a Supp. From there, they can easily reverse engineer the gimmick. Thus, the Supp Style type of RI is very similar to the Same Route type of RI in practice.

Using a Branching type of RI makes the gimmick even less obvious. Rallyists who catch the gimmick will follow a different route than those who don't. Neither RI part will refer to the turn for the gimmick, and often neither group of rallyists (those who get the gimmick and those who don't) will encounter the landmarks used in the RI part for the other group.

Branching type RIs usually makes the rallye flow better too, because there is no need for a U-turn.


With Branching type RIs, it can be helpful to loop one of the routes. That is, the rallyemaster can take advantage of the topography of the roads to bring rallyists who get a gimmick back together with rallyists who miss the gimmick.

Here is an example where rallyists start at the bottom of the map, and some gimmick causes them to turn right at Oak & Smith:

            |   |       |   |
 ___      J |   |       |   |
|   | M   o |   |_______|   |___________
|   | i   h |                           |
|   | l   n | \ \ \ \ \ \ \ \ \ \ \ \ \ |
|   | l   s | \  _______     _______  \ |
|   | e   o | \ |       |   | Black | \ |
|   | r   n | \ |       |   |       | \ |
|   |_______| \ |       |   |       | \ |
|             \ |     B |   |     J | \ |
| \ \ \ \ \ \ \ |     r |   |     o | \ |
| \  ___________|     o |   |     n | \ |
| \ | Davis           w |   |     e | \ |
| \ |                 n |   |     s | \ |
| \ |___________________|   |_______| \ |
| \                                   \ |
| X / / / / / X \ \ \ \ \ \ \ \ \ \ \ \ |
| X  _______  X  _______     _______    |
| X |     O | X | Smith |   |       |   |
| X |     a | X |       |   |       |   |
| X |     k | X |       |   |       |   |
  |          /|\  A. L on Smith, L at T
 \|/          |   B. L on Jones, L at T

In this example, rallyists who miss the gimmick will do part A, turning left on Smith (Oak & Smith), then turning left at the T (Smith & Miller). Rallyists who get the gimmick will turn right at Oak & Smith, and then do part B.

However, part B takes them on a longer loop: continuing past Brown, turning left on Jones (Smith & Jones), continuing on Black at the forced turn, continuing past Brown again, turning left at the T (Black & Johnson), continuing on Davis at the forced turn, and turning left at the uninstructed T (Davis & Miller). Note that the loop would still work with a T rule that has rallyists turn right at the uninstructed T (Davis & Miller), because they would reverse their direction of travel in the cul-de-sac (Miller).

As the above example shows, a rallye's T rule can be used to simplify RI(s) used to loop rallyists back on route. However, excessive reliance on the T rule can confuse rallyists.

Gimmick Ideas

Signs, Roads, or Objects

It is common for an A-B rallye to use quotation marks to indicate signs and non-quoted text to refer to the road itself or to a defined object, such as a SIGNAL or T. Example GIs:

If an RI part uses quotation marks, then it refers to a sign bearing all the word(s) and number(s) that appear within its quotation marks.
If an RI part has no quotation marks, then it refers to the object, if it is defined, and otherwise to the named road itself.

Using these, and a definition of ON as "physically upon"

R on "SMITH"

means to drive over the sign reading SMITH, which is unsafe.

R at "T"

requires a sign with the word "T"; a warning of a T intersection ahead may qualify.


Many A-B rallyes place importance on sign location: on the left, on the right, or anywhere (or difficult to see). And is it important where the sign is as you approach it or as you pass it? There is a difference when you turn. And are multiple surfaces on the same pole considered all one sign or separate signs?

Older A-B rallye required signs to be on the right unless otherwise instructed. Rallyists often prefer that all sign location restrictions are explicit. Sample definitions:

SOL (Sign on Left): Sign must be on the left as you approach it.
SOR (Sign on Right): Sign must be on the right as you pass it.
SA (Sign Anywhere): Sign may be anywhere, including overhead, or may be hard to see.
*: The use of an asterisk (*) in an instruction requires sign(s) to be on the left as you pass.

Stinker: The last of these subtly applies to the instruction, rather than to the RI part A or B.

Intersection Types

You can define that certain terms limit what types of intersections are acceptable. Examples:

CH: An chance to turn at an intersection where pavement meets but does not cross
PAST: Beyond the sign or landmark, turning at an intersection where roads cross each other
S: Straight at an intersection where pavement crosses in both directions

Reads In Part (RIP)

RIP requires that the text quoted in the instruction is a proper subset of the text on the sign. That is, the sign must also have something more. Sample definitions:

RIP (Reads in Part): Other word(s) or number(s) are on the sign, in addition to those inside the instruction's quotation marks.
RIP (Reads in Part): Some, but not all, of the words that exist on the sign appear in the instruction.

After / Past

Sometimes, a rallye can avoid having multiple actions for an A or B part, simplifying the rallye for those new to A-B rallyes. One way to achieve this is to define AFTER or PAST, perhaps as "Beyond the sign or landmark in question." Now, rather than "C at Smith, R at Jones" an RI part can read "R at Jones after Smith".


Example Scoring Templates
Simple Scoring
1. A B C     11. A B C
2. A B C 12. A B C
3. A B C 13. A B C
4. A B C 14. A B C
5. A B C 15. A B C
6. A B C 16. A B C
7. A B C 17. A B C
8. A B C 18. A B C
9. A B C 19. A B C
10. A B C 20. A B C
Combo Scoring
1. A B C     11. A B C
2. A B C 12. A B C
3. A B C 13. A B C
4. A B C 14. A B C
5. A B C 15. A B C
6. A B C 16. A B C
7. A B C 17. A B C
8. A B C 18. A B C
9. A B C 19. A B C
10. A B C 20. A B C

TRC's computerized scoring system does not handle A-B rallyes well. It is easier to score A-B rallyes with templates made from overhead transparency sheets. Transparency markers (or in a pinch, dry-erase markers) can be used to mark the template. When a transparent template is placed over a score sheet, everything recorded on the score sheet can be seen. Sometimes teams make additional marks on their score sheet that might not show through the windows of a paper template.

It is often helpful to have two scoring templates for a rallye. The first template indicates everything that is simply worth +10 points. Scoring this template is easy: count the answers that match this template and append a zero (i.e., multiply by 10). The second template indicates everything else, and usually the more experience person scores this template. A third person can add the two subtotals, and add the finish points awarded to everyone to make a perfect score total 1000 points.

For these example scoring templates, all the RIs except 9 and 16 are simply scored 10 points for the correct answer. Both RI 9 and RI 16 have full-credit answers worth 10 points, and partial credit answers worth 5 points.

See Also

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