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Discussion: Choose-your-forking event format

in: Vancouver Sprint Camp 2018 (Feb 16–18, 2018 - Vancouver, BC, CA)

Feb 19, 2018 5:33 AM # 
IOF are currently considering several gimmicks for use during a sprint knockout competition at WOC2020. You can read the proposals here. We tried the "course choice model" at the 2018 Vancouver Sprint Camp (also referred to as choose-your-forking).

Our courses

Here are the three forkings competitors could choose from. Competitors were given 30s to make their choice.

C was both the shortest AND least technical option.

There were a few interesting patterns:
* There was a pretty even split between selecting A/B/C.
* Most of the very fast people chose C.
* Several people who chose B did so because they preferred it to A, and didn't have enough time to study C.
* Several people who chose A didn't see the little trap that makes it longer.

Choice analysis

To see which forking was fastest, I looked at the fraction of time of the race each competitor spent in the forked section. This should account for each competitor's speed, but there may still be outliers if people blew up at some point in the race.

At Sprint Camp we split people into Expert and Elite categories. The forkings were the same for both, but the Expert course was shorter before and after the forked section.

We see that C saved ~2% overall. This is ~15s for the fastest runners. This is actually less than the time some competitors lost by choosing a poor route to #1 in the full course.

Competitor feedback

We had a show of hands at the evening banquet for "who liked the new format?". It was about 50/50. Some elite logs I've seen so far say they aren't convinced either.

The main issue seems to be that if you choose the same forking as another competitor, then it becomes a straight footrace. This could be negated with butterflies later on, if it wouldn't make the course too contrived.

Organisational aspects

In the IOF proposal, there are 6 competitors starting in each wave, and each competitor has their own private start lane in which to make their decision. The goal of this is to make the decision in secret, so you only find out what the other 5 people chose when you reach that part of the course.

We did not have the infrastructure or the manpower for that. We used waves of 4, and had 4 copies of the "choices" map on a table. Each competitor had a volunteer stationed next to them. After the 30s inspection period, the runner whispered their choice to the volunteer, who then retrieved the full map for them from a cache that was out of sight. So, the whispering means that you don't know what the other 3 people are running; the hidden cache of maps means you can't tell what the 60 people before you chose by looking at the number of A/B/C maps left.

We needed twice as many volunteers in the start lane for this race than any other race during the weekend.

We needed to print 3 times as many maps for this race, as we needed enough in case everybody chose the same forking.


This format is a lot of extra work, wastes a lot of paper, and received a lukewarm reception from competitors. Being able to quickly interpret the map and make good route choices are obviously key. But these skills are tested on any course; I'm not sure what the advantage is of also testing them while stood still.

If you were at Sprint Camp and want to leave feedback on the event (positive or negative), please do so. We will eventually compile a report to send to IOF.
Feb 19, 2018 12:04 PM # 
In the Billygoat, when forked, participants would receive a map showing both forks, and the orienteer would simply decide on which fork to take. With a Sprint, perhaps that would result in too confusing course markings, depending on the complexity of course and degree of forking. But it would reduce the usage of paper and of volunteer effort, as well as the standing still. (Not opining on whether this is a worthwhile format.)
Feb 20, 2018 11:23 PM # 
I was thinking on the way home - a way that could eliminate the need for a volunteer for each racer or a screen between each start lane would be to randomize which forking is A, B, or C between starters.

(This is the "there is too much, let me sum up" moment....)

Let's say you've got the three forkings, A, B, and C, and say six starters in a wave. When the first racer walks up to the start, they have the hidden map with the three forking choices labeled 1, 2, and 3, and three corresponding bins of maps (note, there will be three bins of maps for *each* starter). What the racer doesn't know is that forking choice 1 corresponds to, say, option B, while choice 2 corresponds to option C, and choice 3 corresponds to option A. They choose, say, number 2, grab a map from the bins at their station marked number 2, and they go off and run - and have forking option C on their map (not marked as such though, to prevent friends comparing maps while running).

The station for each starter has a different correspondence between the bins 1, 2, and 3, and forkings A, B, and C. (And coincidentally, there are six ways of making that correspondence.) So that way, nobody knows which forking each competitor will take based on which bin they've pulled a map from, because *for each racer, the 1, 2, and 3 bins have the forking options in different orders*.

You'd only need probably one volunteer to do the 30 second countdown for all six racers. Fewer volunteers, and you only have to screen the start from other competitors who haven't started.

I've been also thinking about trying to do something similar with a "choose your own forking," but mid-race - you get to some point mid-race, then have to look at a map excerpt and choose which of the three forking options you're going to take, with the same 30 second limit...but the time spent looking at the map is counted as part of your overall time...
Feb 20, 2018 11:26 PM # 
Okay, so you'd need one more volunteer - you could have just one copy of each map in each bin, and after a wave of starters leaves, a volunteer replaces the ones that were taken with a new single copy, so you can't see that there are way more copies of two of the maps remaining.

Granted, you'd have to be careful not to mix things up....
Feb 21, 2018 12:31 AM # 
The only way to get this into the Olympics would be to introduce a half-pipe in the start chute.

This discussion thread is closed.