Kepler Challenge – Splits

kepler_SMRunning the Kepler can be tricky and getting your pacing wrong can make the last section from Rainbow Reach long. Really messing up your pace and the run down the Iris Burn can be very very long. While seeing people implode so badly they are reduced to walking down hill has a certain entertainment value, what is far more entertaining is seeing people run to their full potential. So to help people cash in on the hard training Matt Bixley has made the tables below to help with pacing.

I deleted Facebook for a while, had some time out. Highly recommended and not even sure why I reactivated it. Perhaps it’s my lack of will power or OCD and like the Kepler, I keep coming back. About an hour into my return (edit: 23 minutes exactly) a request came in for splits on the Kepler, the 2nd request for splits came in precisely 89 minutes after the 1st. The 3rd request ………

So here we are, my favourite time of year, pouring over useless bits of information about an arbitrary, but beautiful loop in a remote part of South-West New Zealand. With Kepler #11 about to be enjoyed with friends here is my best guess at the times you need to run for each section of the track. Actually it’s not a best guess, it is remarkably accurate given the constraints of variation in human performance. There are a lot of caveats and little old heteroscedasticity (look it up and try and say it, even better, try and use it in conversation one day J ) is a bit of an issue. I have data, I developed a model, I used terms like machine learning, k-fold, cross-validation. None of that means anything if you’re not reasonably fit, aware of your abilities and realistic about your goals.

Above Luxmore Hut

Above Luxmore Hut

The run to Iris Burn should take just a little longer than the run from there to the finish. That should hold true for everyone in an ideal world. But the race is long, so getting things wrong is all too common. It’s all too easy to do the first half much harder than your skills dictate. I say skills, because even the fittest can outrun their abilities in the 1st half, particularly in getting to Luxmore Hut. There is many a story of a 72 minute trip and 4th place to Luxmore, followed by a grovel home in 6 plus hours.


Having goals is worthwhile, but the above tables should be used as a tool, not a target. If you have a time goal, but the split to Luxmore finds you putting in too much effort, you’d better give up on your goal and settle down. You have more chance of getting close to it if you let it go. If you keep pushing you will suffer. The 1st three quarters of the run HAS to feel comfortable and easy (read  My Way  to understand what I mean). Sometimes however, the risk of blowing up is worth it. Two of the three splits that I’ve tailored, are for specific, down to the minute goals, sometimes there is nothing more satisfying than the personal races between mates to beat their time. That holds true for the full length of the field, not just the Martin Dents. Speaking of whom, these are Martin Splits for his 2013 course record 4:33:37

Brod Bay – 20 min
Climb to Luxmore Hut – 44 min
Forest Burn – 26 min
Hanging Valley – 20 min
Iris Burn – 30 min
Rocky Point – 36 min
Moturau – 34 min
Rainbow Reach – 24 min
Finish – 39 Min

Some interesting things to note about those. Several 5+ hour runners get to Brod Bay in 21 minute each year. Phil Costley reached Luxmore 1 minute quicker in his record run and ran the last section 2 minutes quicker. Several people each year run 30-31 minutes for the descent to Iris Burn, ie Course record pace, slow down. Both Martin and Phil while not only talented, were clearly very aware of their own strengths and weaknesses and ran to those.

As an about to be unemployed statistician I should be selling this information. Offers of jobs, cash and beer would be greatly appreciated thanks. If anyone wants something specific and/or tailored to their skills and goals then let me know and I can work something out. email:

Accuracy: >95% if you run smart,


About Mouth of the South

Matt Bixley has written 24 .

Outspoken and opinionated- which is great cause we never have to guess what is on his mind. “The Mouth of the South” started his love of trail running with a 8hr+ Kepler in 2004. Since then he has run 220+km in 24hr while representing New Zealand and now has 5hr50, top 10 finish to his name. You can follow him HERE on his personal blog

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