Sunday, December 30, 2012

Start time differentials in the TOTW

So, here's my take on what happened with start time differentials in the TOTW.

The standard way to calculate differentials for a given musher is to subtract his bib number from the total number of entrants and then multiply by the start interval. So, for example, the differential for bib 25 in a race with 25 entrants and a 3-minute gap between starts would be 0, because

(25 - 25) * 3 =
0 * 3 =
0

Note that this seems intuitively correct.  (Good rule of thumb - if the last musher out has a differential other than 0, ask what's going on).  Similarly, bib 13 in a race with 25 entrants and a 2-minute gap between starts would be 24 minutes, because

(25 - 13) * 2 =
12 * 2 = 
24 

But on the TOTW website, we have a problem.  Let's look at Lance Mackey, who's got bib 16 in a field of 23 (note that the honorary musher Chief Isaac Juneby is shown as starting at 14:00, and the musher who was actually on the trail first left at 14:02).  So, Lance's start differential should be:

(23 - 16) * 2 = 
7 * 2 =
14

The earliest time out of Chicken should be 4 hours from arrival plus the start differential.  In Lance's case, he arrived into Chicken at 2:34, so his earliest time out should be

(2:34 + 4 hours) + 14 minutes =
6:34 + 14 minutes =
6:48

but if you look at his earliest out on the website it says 6:52 - 4 minutes more.  If you go through the list of mushers everybody's got an extra 4 minutes tacked on.  Except ...
Jake Berkowitz has bib 22, so his start time differential should be 2 minutes (this one's easy!).  If the same error applied to everybody else had been applied to Jake, his earliest time out should be his arrival in Chicken time + 4 hours + 6 minutes (with the extra 4 minutes tacked onto the correct start differential).  He arrived at 4:04, so his earliest departure time (including the 4-minute error) should have been

(4:04 + 4 hours) + 6 minutes =
8:04 + 6 minutes =
8:10

On the website, which may be maintaining their own numbers independently of the checkpoint staff (that is to say, the numbers may be different in the two places and the website should never, ever, ever ever ever be taken as authoritative for any race in progress), it says that his earliest time out should have been 8:22.  Oops.  That's basically a 12-minute unearned penalty, if that's the official time.

According to the website, everybody who's out of Chicken so far left at the (incorrect) earliest out listed on the website.  (Gerry went out a minute later - his prerogative).  Jake is listed as having gone out at 8:22.  However, if you look at his personal tracker he started moving sometime between 8:11 and 8:14 (looks like he reset his tracker at 8:14 - such a mensch!).  

If I had to guess, I'd guess that they have his incorrect-but-correct time at the Chicken checkpoint - they have the 8:10 time, not the 8:22 time, and that the folks maintaining the website are in some cases just using their own earliest time out as the departure time, rather than the actual departure time.  Telecommunications and internet access in remote parts of Alaska is extremely difficult and satellite phones are insanely expensive (for airtime), so if they want to show that someone's actually left and don't yet have the real departure time, this doesn't seem unreasonable.  This one just popped out because 1) Jake's start differential was calculated incorrectly on the website, and 2) Jake has a tracker so everybody out here in internet-land can see what's going on.

I tend to think there's not actually a problem in the race, just in the website.  Fortunately if there is a problem in the running of the race, the estimable Mike McCowan is the race marshall and we can be confident that any problems will be resolved in a way that's both legal and just.

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