This is really just a bit of fun but it may have a bit of practical use as well, if anyone is contemplating a race and wants an opinion on how hard it is compared to another that they may have already done.
So I have attempted to evaluate a few of the races that I have done over the years and then put them in a "graded list" of how difficult they are to complete. I have always operated at the more modest end of ultra events so my "most difficult" race is a relatively easy undertaking by modern standards, but I would be interested to know how some of the popular more difficult events compare.
I'll start by explaining the factors I used to try and make a comparison, and how they affect the chance of completion, then go on to my list at the end. I have only included races that I have actually completed under race conditions, or for just two where I know the ground extremely well and have done a comparable race on the course. Also, I have included two races (the Mercian Challenge and the Lakes Traverse) which I have not done as themselves but completed within the time allowed when doing their "parent" races (Offas Dyke and the Northern Traverse respectively). I have excluded non-UK races as I haven't done enough to make good comparisons, and winter races (Dec-Feb) held in mountain regions, because they present completely different challenges and are not really comparable.
So here we go, first the factors I considered:
1. Time of year
Not guaranteed, but in general and on average there are months when the weather will be kinder, and that will make your race easier. You will have less mud and wet ground underfoot, carry less kit, do generally less faffing and need less regrouping time in checkpoints. How much of the race a "completer" will have to face in darkness is also a factor which increases difficulty.
2. Length
Obviously, all other things being equal, a longer race is harder than a shorter one. But other factors may sometimes be more important than length.
3. Height Gain
Again obviously, the more uphill you have, the harder it gets. But how much uphill is there? The race director will tell you how long the race is, and apart from an odd one or two percent no-one will really disagree; satellites are pretty accurate for horizontal positioning and plotting. But he will also tell you how much ascent there is, and the figure he gives you will depend on what system he uses to measure it. For reasons which I won't go into here, all the systems (Strava, Garmin, OS, Trace de Trail and so on) use different algorithms, mapping systems and accuracies, so can come up with wildly different estimations of height gain. What I have done to get a common comparison is to plot all the races I have considered on the OS map system, without using the "click to trail" feature (which again changes the result but is only available for routes in National Parks), as accurately as I can, and then use the OS height gain estimation. This means that some of the figures you will see won't agree with what the race is advertised as, but they will at least all be comparable with each other.
4. Rate of Climb
This is important. If your race gains 10,000ft over 30 miles, that's a different game from one gaining the same height over 50 or 100 miles, in terms of how much ground is likely to be runnable. I have just taken a straight average here, total height gained divided by distance travelled. The purists may not agree with this but again, it gives a good comparison between different events.
5. Ground Difficulty
It's easy to get bogged down (no pun intended) here with subtle differences, but it is clearly easier to run on a road or well-gravelled jeep track than over a boulder field. I have kept this simple with a three grade rating. Grade 1 is a route which includes lots of ground where you can run steadily without looking at your feet, grade 2 is where you will regularly need to look where you are putting your feet and make fairly frequent adjustments to individual stride and foot placings, grade 3 will contain significant sections where you will be using your hands.
6. Longest Distance between Food Resupplies.
This makes a diffence to difficulty because as the distance to food resupplies goes up, obviously the amount you have to carry with you increases, but also your options for choice goes down. With regular well stocked feed stations you can make choices as you go, as mood and appetite varies. Without them you have to live with your pre-made choices for much longer periods. The easiest situation for the runner is if the race permits a support crew, I have just noted these as "SC" in my table. At the other end of the scale are events where you have to go for days with what's in your pack. Some events allow competitors to access shops, cafes, pubs, etc along the way, which obviously mediates the distance between resupplies, and I have indicated these. Other events ban the use of such establishments.
7. Time Allowance
The physical nature of a course and access to support points goes some way to define the undertaking. But the over-riding factor that makes a race easy or hard is the time allowance you have to complete it. The Lakeland 100 follows a route that many middle-aged ramblers would be happy to complete in a week or ten days; cut the limit down to 40 hours and around half of the (hopefully) trained ultra-runners setting out on the course fail.
8. Minimum Average Speed
This in theory is the overall difference divided by the time allowed, but it doesn't always work like that. Some multi-day races have the same time allowance for days of different distances, and some continuous races have intermediate cut-offs that demand you go faster over some sections than the overall average. The figure I have given is the highest speed you will have to maintain for a significant proportion of the race to meet cutoffs. This gives an idea, especially important in hilly events, of how much you will actually have to cover at a running pace to meet this average speed.
I've also added a couple of bits of post-event data which I think contribute in some way to the comparisons of overall difficulty. These are (a) the current race record, where I have been able to find it, and (b) the percentage of the starting field which finished. For the the latter, I have just taken a snapshot of the result of all events in 2019. I could find an average but it would be a lot of work and probably doesn't give you much additional information.
In arriving at a ranked list I haven't attempted to build an algorithm. This has been tried by people more competent than me, but they throw up silly anomalies because evaluating and weighting the various factors is so complex. I think an overall judgement having done the events is at least (and possibly more) accurate. But of course, other runners who have done the events may come to a different conclusion, and that's maybe part of the fun.
I have also included a few events in the table below my ranked list. I know the ground very well on these but have either never attempted or never completed them so can't really make a judgement on their rank. I would be interested if anyone who has done them could help out here. Note that the figures for the Dragons Back are in its current 6 day form which is much harder than previous years.
So here we are!
