running

R Package for @racently

An R wrapper for the @racently API.

An API for @racently

Retrieving running data using the @racently API.

Comrades Marathon (2019) Splits

I’m looking at ways to effectively visualise the splits data for the 2019 edition of the Comrades Marathon. My objectives are to provide: an overall view of the splits across the entire field and a detailed view for individual runners (relative to the rest of the field). Ridge Plot My working solution for visualising the global splits data is a ridgeline plot created with the {ggridges} package.

Medal Breakdown at Comrades Marathon (2019)

A quick breakdown of the medal distribution at the 2019 edition of the Comrades Marathon. This is what the medal categories correspond to: Gold — first 10 men and women Wally Hayward (men) — 11th position to sub-6:00 Isavel Roche-Kelly (women) — 11th position to sub-7:30 Silver (men) — 6:00 to sub-7:30 Bill Rowan — 7:30 to sub-9:00 Robert Mtshali — 9:00 to sub-10:00 Bronze — 10:00 to sub-11:00 and Vic Clapham — 11:00 to sub-12:00.

Comrades Marathon (2019) Start Delay

How long does it take to cross the start line at the Comrades Marathon? If you’re lucky enough to be starting in one of the batches which is close to the front then this might be a matter of seconds to a couple of minutes. But if you’re in a batch closer to the back then this could be anything up to ten or eleven minutes. This is an agonising wait when all you want to do is start running.

A Shiny Comrades Marathon Pacing App

The Comrades Marathon is an epic ultramarathon run each year between Durban and Pietermaritzburg (South Africa). A few years ago I put together a simple spreadsheet for generating a Comrades Marathon pacing strategy. But the spreadsheet was clunky to use and laborious to maintain. Plus I was frustrated by the crude plots (largely due to my limited spreadsheet proficiency). It seemed like an excellent opportunity to create a Shiny app.

Spirit of the Comrades

Great video bringing back some good memories.

GPS Doodling

Stephen Lund combines two of my passions: technology and exercise. Awesome. Durban Doodles coming soon.

Comrades Marathon Medal Predictions

Comrades Marathon Finish Predictions

Comrades Runners Disqualified: I'm Not Convinced

Apparently 14 runners have been disqualified for failing to complete the full distance at the 2012 and 2013 Comrades Marathons. I’m not convinced.

Comrades Marathon Pacing Chart: Up Run

I’ve updated my Comrades Marathon pacing chart to include both the Up and Down runs. You can grab it here. The data for this year’s race are not yet finalised (I think we will be running 87 km), but you can make changes when it’s all confirmed.

Comrades Marathon: A Race for Geriatrics?

It has been suggested that the average Comrades Marathon runner is gradually getting older. As an “average runner” myself, I will not deny that I am personally getting older. But, what I really mean is that the average age of all runners taking part in this great event is gradually increasing. This is not just an idle hypothesis: it is supported by the data. If you’re interested in the technical details of the analysis, these are included at the end, otherwise read on for the results.

Comrades Marathon Negative Splits: Cheat Strikes Again

It looks likes one of the suspect runners from my previous posts cheated again in this year’s Comrades Marathon.

Twins, Tripods and Phantoms at the Comrades Marathon

Having picked up a viral infection days before this year’s Comrades Marathon, on 1 June I was left with time on my hands and somewhat desperate for any distraction. So I spent some time looking at my archive of Comrades data and considering some new questions. For example, what are the chances of two runners passing through halfway and the finish line at exactly the same time? How likely is it that three runners achieve the same feat?

Comrades Marathon Pacing Chart: Down Run

Although I have been thinking vaguely about my Plan A goal of a Bill Rowan medal at the Comrades Marathon this year, I have not really put a rigorous pacing plan in place. I know from previous experience that I am likely to be quite a bit slower towards the end of the race. I also know that I am going to lose a few minutes at the start. So how fast does this mean I need to run in order to get from Pietermaritzburg to Durban in under 9 hours?

Race Statistics for Comrades Marathon Novice Runners: Corrigendum

There was some significant bias in the histogram from my previous post: the data from all years were lumped together. This is important because as of 2003 (when the Vic Clapham medal was introduced) the final cutoff for the Comrades Marathon was extended from 11:00 to 12:00. In 2000 they also applied an extended cutoff.

Race Statistics for Comrades Marathon Novice Runners

Most novice Comrades Marathon runners finish the race on their first attempt and the majority of them walk (shuffle, crawl?) away with Bronze medals.

Comrades Marathon Negative Splits: The Plot Thickens

I have been thinking a little more about those mysterious negative splits. Not too surprisingly, this thinking happened while I was out running along the Durban beachfront this morning.

Comrades Marathon: Negative Splits and Cheating

With this year’s Comrades Marathon just less than a month away, I was reminded of a story from earlier in the year. Mark Dowdeswell, a statistician at Wits University, found evidence of cheating by some middle and back of the pack Comrades runners. He identified a group of 20 athletes who had suspicious negative splits: they ran much faster in the second half of the race. There was one runner in particular whose splits were just too good to be true. When the story was publicised, this particular runner claimed that it was a conspiracy.

Updated Comrades Winners Chart

On Friday I received my copy of The Official Results Brochure for the 2013 Comrades Marathon. Always makes for a diverting half an hour’s reading. And the tables at the front provide some very interesting statistics. Seemed like a good opportunity to update my Chart of Comrades Winners.

A Chart of Recent Comrades Marathon Winners

Continuing on my quest to document the Comrades Marathon results, today I have put together a chart showing the winners of both the men and ladies races since 1980. Click on the image below to see a larger version. The analysis started off with the same data set that I was working with before, from which I extracted only the records for the winners. > winners = subset(results, gender.position == 1, select = c(year, name, gender, race.

Comrades Marathon Inference Trees

Following up on my previous posts regarding the results of the Comrades Marathon, I was planning on putting together a set of models which would predict likelihood to finish and probable finishing time. Along the way I got distracted by something else that is just as interesting and which produces results which readily yield to qualitative interpretation: Conditional Inference Trees as implemented in the R package party. Just to recall what the data look like:

Are Green Number Runners More Likely to Bail?

Comrades Marathon runners are awarded a permanent green race number once they have completed 10 journeys between Durban and Pietermaritzburg. For many runners, once they have completed the race a few times, achieving a green number becomes a possibility. And once the idea takes hold, it can become something of a compulsion. I can testify to this: I am thoroughly compelled! For runners with this goal in mind, every finish is one step closer to a green number.

The Green Number Effect

Following up on a suggestion from my previous post, here are the statistics for medal count versus age.

Age Distribution of Comrades Marathon Athletes

I can clearly remember watching the end of the 1989 Comrades Marathon on television and seeing Wally Hayward coming in just before the final gun, completing the epic race at the age of 80! I was in awe. Since I have been delving into the Comrades Marathon data, this got me thinking about the typical age distribution of athletes taking part. The plot below indicates the ages of athletes who finished the race, going all the way back to 1984. You can clearly spot the two years when Wally Hayward ran (1988 and 1989). My data indicates that he was only 79 on the day of the 1989 Comrades Marathon, but I am not going to quibble over a year and I am more than happy to accept that he was 80!

Medal Allocations at the Comrades Marathon