Modern Athlete Magazine Issue 124, November 2019 | Page 24

ROAD RUNNING Are We Going to Seed? Left to our own devices at a road race, how do we seed ourselves at the start? The fast guys and gals should be at the front and the slower runners at the back – that’s the way it’s supposed to work, since we all know our abilities and position ourselves at the start line appropriately. Well, the recently completed 2019 Vitality Run Series in Johannesburg provides an interesting insight into how well (or badly) we seed ourselves. – BY MARK KRUG The top runners should be right up front and they will cross the starting mat in the first few seconds, and being top runners, they will also be amongst the first finishers. Slower runners will take longer to cross the starting mat, and we would expect to see them finish towards the back of the field. Thus we should see a broad correlation between starting delay and finish position. However, that correlation is pretty hard to see in the four charts below. Plotting the Results Each red dot represents a runner, and if we all magically seeded ourselves perfectly, all the red dots would be on the thick blue line (or thereabouts). The blue line is curved because of the squash factor – up front it’s more squashed than further back, so more runners cross the start line in a given time interval at the front than further back. At Old Eds, 24 for instance, 735 runners crossed the line in the first minute, 529 in the second minute, 425 in the third minute, 323 in the fourth minute, 253 in the fifth minute, and so on. Runners above the blue line have big start delays – they position themselves further back in the crowd, but they then finish the race faster than their positioning suggests. I’ll say that these runners are underestimating their ability and should move forward. On the other hand, we have runners who are overestimating their ability – they cross the line quickly because they’re right up front, but they end up finishing way back. Of particular interest are the extremes, those in the top left corner and those in the bottom right corner. At Old Eds, there were three runners who crossed the mat eight to nine minutes after the gun and yet finished in the first 200. It’s not hard to imagine what happened here: Top runner is stuck in traffic, or transport is late to the start. In the bottom right corner it’s possible that a top runner positions themselves right up front, but picks up an injury and hobbles home at the back. Getting it Right Of course, there will be many individual stories about why a particular runner’s dot is positioned where it is, but on the whole, we should see a broad cluster of dots around the blue line. In the case of the Vitality Series, where the last runners cross the mat about ISSUE 124 NOVEMBER 2019 / www.modernathlete.co.za six minutes after the gun, I would suggest that if we positioned ourselves even remotely correctly, we should be within two minutes of where our ability (as demonstrated by our finish position) suggests we should be. On the charts below, that means that if we’ve got it roughly “right,” we should be positioned between the two dashed blue lines. If we go with this two- minute leeway, then it works out that in all four of the races, around 30% of the field do not position themselves appropriately for their ability. If we get a little harder on ourselves and say that we should be able to position ourselves within one minute of “perfect,” then a full 55% of us are not getting this right. Food for thought. Get Your Results So, this is all about learning, right? If you’d like to know how well you positioned yourself, then e-mail your name to [email protected], and which race(s) you entered in this series, and I’ll send you a return e-mail showing where you plot. That way you can learn from this, position yourself better next time, and thus more runners will be happy. About the Author: Mark Krug is a geologist and parkrun devotee who discovered running at age 50, going from #parkruntoComrades. He describes himself as “definitely not a statistician, but an Excel geek,” and says half the reason he runs is for all the numbers it generates. T he 2019 Vitality Run Series Joburg consisted of four iconic races, the Old Eds, Wanderers, FIBO Africa Challenge with Randburg Harriers and Rockies Gerald Fox Memorial races, which took place from 11 August to 15 September. The timing service provider of the Vitality Series conveniently provided both gun-to-mat and mat-to-mat times for these four races, which allows us to subtract one from the other and calculate, for every individual, the time they took to cross the mat after the gun went off. I’ll call this the start delay. For the Vitality Series, it takes around six minutes for most of the athletes to clear the starting mat.