Colour Coded Course Lengths

[greywolf]

Yet the same weekend I notice a small level C event where Alan Velecky (is it fair to say 20+% behind top elite?) won blue in 38 minutes. My rough in the head calculation suggests that ths course was therefore about half the length dictated by the guidelines, except of course that at the same time as giving fairly clear time targets the rules also give a range of distances which completely fail to account for areas as fast as Friston, or as slow as some. Anyway no-one has complained about this event or any of the majority of level C events where the course lengths do not conform to the guidelines.

There are complaints about them too but no-one takes the slightest bit of notice - too many old folk who like the ego trip of still believing they can do a Blue course in an hour or whatever.
Your in the head calculation has gone badly awry. SJC's sums work when you know the speed of the terrian - but a simpler method is that the Black course would take a top elite 67 mins (to which i'd add "plus or minus 10%"), and a Blue course should be 56% of this, so 67 * .56 = ~ 37 mins 30secs (likewise plus/minus 10%) so it was a bit short but not half the expected length.
The guidelines state "The lengths shown are intended as a guide" - it's unfortunate that the table is labelled "min-max length" - should be something like "indicative range"

[graeme]

Something I don't understand about the length guidelines...

Even the best runners can do +-5% on a good/bad day. And even the best planners can get courses to within +-10% (see e.g. WOC). And the weather can add another +-10%. So in the best case normal variation would be +-25% *.

My question is whether the spread suggested in the rules represents this normal variation (i.e. the planner must aim for the 67 min winning time, but competitors should understand
the possible variation). Or whether the planner is allow to aim for one end of the range, knowing that the natural variation may push it outside the range.

One other point. While its OK to offer advice, nobody should complain about a level D event. Slapping out some tapes 2mins ahead of the first runner should be fine at this level. Getting the controls in the right place on somewhere like Craig a' Barns exceeds my expectations for level D (they didn't manage that at the last SOL I ran there...)

* Yes, I do know errors don't add like that.

[SJC]

There is a tendency to over-complicate things in this sport. Guidelines say:
Brown 8.5 - 12.0 km ; Blue 5.5 - 7.5 km ; Green 3.5 - 5.0 km

So simply knowing the areas would suggest that:
Brown 11.0 km ; Blue 7.5 km ; Green 5.0 km is probably about right at Friston,
whilst:
Brown 8.5 km ; Blue 5.5 km ; Green 3.5 km is probably nearer the mark for Craig a'Barns

No complicated maths or course length ratios. Plan the best courses possible at about those lengths and you are unlikely to get any complaints.

[Grahame N]

There is a tendency to over-complicate things in this sport. Guidelines say:
Brown 8.5 - 12.0 km ; Blue 5.5 - 7.5 km ; Green 3.5 - 5.0 km

So simply knowing the areas would suggest that:
Brown 11.0 km ; Blue 7.5 km ; Green 5.0 km is probably about right at Friston,
whilst:
Brown 8.5 km ; Blue 5.5 km ; Green 3.5 km is probably nearer the mark for Craig a'Barns

No complicated maths or course length ratios. Plan the best courses possible at about those lengths and you are unlikely to get any complaints.

On Sunday at Craig a Barns my Blue was 6.6km and Green was 4.8km and I didn't get any complaints. The only complaints have been on Nopesport from people who were not there.

[greywolf]

My question is whether the spread suggested in the rules represents this normal variation (i.e. the planner must aim for the 67 min winning time, but competitors should understand the possible variation). Or whether the planner is allow to aim for one end of the range, knowing that the natural variation may push it outside the range.

Nope, it means the planner should aim for a 67 min top elite winning time, and based on the usual range of terrain types in GB this will give a black course length between 10 and 14 km (which equates to a range of speeds from 6.7mins/km to 4.8 mins/km). In extremely tough terrain (Trossachs) the black course would be < 10km, if you found somewhere quicker than 4.8 mins/km it would be > 14km. And then the other courses are scaled from this (taking climb into account): brown 85%, blue 56% etc. Unfortunately it's not presented very clearly, and there are some obvious maths fails (e.g. the indicative range for green should be 3.9 - 5.5km).

Of course planners can't be expected to get it spot on and conditions on the day will have an effect, so assuming plus or minus 10% gives a black course elite winning time of 60 - 74 mins range, which gives a fair amount of leeway.

Mu understanding is that it was intended to remove the indicative course lengths completely, as all they seem to do is confuse the issue (and there is a small but vocal group of moaners who seem to think the course lengths in the tables include allowance for climb which explains why events at one of the nearby clubs are often 30% too short...) but they were retained because apparently the maths involved in working through

a) how fast can the fastest people orienteer on this area?
b) how long does the black course have to be for Scott or GG to take 67 minutes?
c) brown course = black course *85%
d) blue course = black course * 56%
e) green course = black course * 39%

is too complicated....

[greywolf]

On Sunday at Craig a Barns my Blue was 6.6km and Green was 4.8km and I didn't get any complaints. The only complaints have been on Nopesport from people who were not there.

Amd if you'd looked at the guidelines and last years JK results, you'd have seen that Doug and Scott did ~ 7.5 mins/km so your notional black course would be 67/7.5 = ~9km thus your blue course would be 9*.56 = ~5km and your green course would be 9*.39 = ~3.5km (these being target lengths with a bit of give and take based on disproportionate climb, variations in terrain etc)

It's hardly rocket science is it? I'm sure your courses were great - but your "green" should have been called "blue" and your "blue" was at least "short brown"

[SeanC]

I think we should relax about this. It's a local event so the market is the neighbouring 2 or 3 clubs. All the experienced orienteers doing blue/green/brown/pick a colour will know what the terrain is like because they will have been there before, or would soon be able to find out, and adjust accordingly.

Normally the inexperienced planners at our local events just do what the previous people did rather than seek out the guidelines and figure out the maths. The seriousness of such guidelines seem out of proportion to the seriousness of the event, though these could be translated/simplified by the club or series co-ordinator.

Getting the standards wrong is only a problem at local events for the newcomers/beginners/juniors courses, and we could mitigate that by giving a 10 minute penalty for missing controls rather than labeling them as failures. Or use different formats eg simple score courses.

You guys up in Scotland getting a JK area for your level D event (emotion for jealousy). Swap you for Ranscombe Farm or Jubilee Country Park.

[Grahame N]

Amd if you'd looked at the guidelines and last years JK results, you'd have seen that Doug and Scott did ~ 7.5 mins/km so your notional black course would be 67/7.5 = ~9km thus your blue course would be 9*.56 = ~5km and your green course would be 9*.39 = ~3.5km (these being target lengths with a bit of give and take based on disproportionate climb, variations in terrain etc)

And my earlier point was that at Local Level D events planners shouldn’t have to spend time doing mathematical calculations. They should be able to lay on events with the minimum amount of work.
My error was to call the courses Green and Blue without knowing if they fitted the guidelines. I should have called them Green-ish and Blue-ish.

[andy]

I should have called them Green-ish and Blue-ish.

What about 'Blue' and 'Brown'

[Grahame N]

What about 'Blue' and 'Brown'

To do that I would have had to do the calculations.

[Spookster]

I should have called them Green-ish and Blue-ish.

What about 'Blue' and 'Brown'

I was thinking that, but resisted saying it.

Meanwhile, in South Yorkshire, the event at Rivelin (a steep, fairly rocky, and generally pretty tough area) was offering a Brown at 6.2km(330m climb), Blue at 4.7km(245m), and Green at 3.6km(160m), all of which look short (and certainly Brown and Blue shorter than the BOF Event Guideline lengths). Brown was won in 55 mins by a reasonably fast M20, and I reckon the best elites would only have managed say 5-10% faster, so in fact these courses were about right. Guidelines are just that, and some areas require much shorter, or longer, courses.

[mappingmum]

I think we should relax about this.

You guys up in Scotland getting a JK area for your level D event (emotion for jealousy).

Exactly. Lighten up guys and well done to TAY and Grahame N.