CB300: Sorting Out The Map vs. The Clock

The Sourdough checkpoint is roughly the half-way mark in the CB300 and a point where we can start to sort out the map vs. the clock. I’ve been encouraging you to focus on cumulative run times between checkpoints because it really is all that matters in the end. In the process, I’ve been saying that Allen is fastest overall and many of you are wondering (and asking!) how that can be if Sebastian Schnuelle is so far ahead of him on the tracker.

Okay, here goes:

Mushers are required to take a total of 18 hours of rest in the four race checkpoints, entirely at their discretion except that one of their rests must be 6 hours in length. In addition, they must “give back” the amount of time they started ahead of the last team to start the race. That’s called the “differential” and it is how the race is made fair between the first musher to start and the last musher who had to wait 96 minutes for his or her turn to start. Thus, the musher with Bib #1 must take a long rest of 7:36 (i.e. 6:00 mandatory plus 1:36 differential) but the musher with Bib #48 must only take a 6:00 mandatory (i.e. 0:00 differential). Everyone in between must take a prorated differential, depending on when he or she started.

For example, Allen started 26 minutes ahead of the last team so his differential is 26 minutes. Aliy started 30 minutes ahead of the last team, so hers is 30 minutes. Spencer started 44 minutes ahead of the last team so he must “give back” a differential of, you guessed it, 44 minutes.

That explains why, in the chart below, Allen took a 6:26 rest in Meiers (i.e. 6:00 mandatory plus 0:26 differential) and why Aliy took a 6:30 rest. They “gave back” the starting time advantage they had over the last team to start. Got it? Take a closer look:

You probably noticed a couple of things: First, almost all of the mushers took their mandatory 6:00 plus differential rests in Meiers. Sebastian Schneulle did not, and that’s why his remaining rest time still includes his 32 minute differential. Second, you may note that Ryne Olson and Nicolas Petit also have uneven rest times remaining. That is simply because the chart in this part of my spreadsheet ignores whatever minutes they “lost” by not leaving checkpoints exactly on 30 minute increments. (Trust me, for your purposes you can ignore them too. Just round off to the nearest half-hour and you’ll be close enough.)

What is most important to wrap your brain around is that Sebastian has only taken 8:00 of total rest (and still “owes” 10:32) versus Allen’s 11:26 of total rest (still owing only 7:00). In other words, Sebastian owes 3:32 more rest than Allen does. No wonder he’s still ahead on the map!

My guess is that Allen will arrive in Sourdough less than 3:32 after Sebastian, which will mean that Allen is “ahead” on the clock if not on the map. By the time Sebastian makes up his extra owed rest time and differential, it is very likely that he will be behind Allen on the map. That may take another checkpoint to do, but it will all tighten up soon.

So here’s the key: If you look at positions on the tracker, make a mental calculation about how much rest time is still owed by the respective mushers and compare that to the distance/rate between them. Being ahead on the map doesn’t necessarily mean you’re ahead in the race… At least not yet!