sutherland to surf 2009 results

Last weekend I ran in the 2009 Sutherland to Surf, an 11km “fun run” (or walk) from Sutherland to Wanda beach. I’ve not run in a fun run before, so I learnt a thing or two this time around. This included:

• An overcast morning in late July in Sydney can be quite cool. The apparent temp was about 6° C. I noticed lots of chattering teeth as we waited to start.
• The start is not really the start. Well, unless you manage to snag a position way up the front of the pack at the start of the run. When the starter’s gun fired (barely audible over the loud music playing), as far as I could tell, nothing actually happened. I stood towards the back of the pack and it took almost 3 minutes before I reached the starting line!
• When almost 4,000 people start a run, it begins slowly. Yep, I was way back in the pack and had to dodge lots of people at the beginning (dodging continued throughout the run, but there was a lot more of it at the beginning).

Now I had planned not to start at the front. The run was timed using RFID tags attached to our shoes, so it would be possible to accurately record the time taken to traverse the 11km course regardless of the time it took to get to the starting line. Furthermore, I figured that if I began towards the back I’d pass more people than would pass me. That’d be my preferred arrangement! Of course I’d not really appreciated the downside: that’s a lot of people to pack into a small space and so my first kilometre or so was somewhat slower than I had expected! Perhaps, if I run it again, I might try to get a starting position closer to the front. As it happened, I worked out that I passed about 2,800 runners as I ran the course.

Anyway, having something of a mathematics background, the other interesting aspect is the statistics involved. Consequently, I include here some graphs I’ve assembled from the results posted on the website linked above. In this case the median values are far more meaningful than averages, which can be significantly skewed by a few stragglers. So here’s the median data for the various groups in the race:

The values on the bars are seconds. If you ran and your time is less than the median value for your group, you were in the top half of runners in your group.

Also of interest is the rate at which runners cross the finishing line. Here’s a graph of my group (40–49 year old males, if you must know) showing the time in minutes along the bottom and the number of runners from the group finishing in the specified time. The times are net times (i.e. the time taken from starting line to finishing line) not gun times (i.e. the time between the starter’s pistol firing and crossing the finishing line). The blue line is the actual data, the green is an approximate gamma distribution curve.

All the different groups should produce a similar distribution, although the peak will shift and the spread would change.

I’ve taken one lesson from the run (at least): 4,000 people is a lot of people to get running together. I can’t imagine how getting the 60,000 or so expected in the City to Surf can work, so I won’t be running in that!

Oh, and as for the merchandising, I may have been tempted by the shirts if it wasn’t for the fact that the apostrophe on the 09 is BACKWARDS!