Originally Posted by Helmet Head

For about the last 72k of the stage, 30k is up, and 42 is down.

Let's say Rasmussen is 2km faster on the up (20k/h vs 18k/h avg), and 2km slower on the down (60k/h vs 62 k/h).

30k @ 20k/hour = 1.5 hours
30k @ 18k/hour = 1.66 hours. Ras gains .16 hours, or 9.6 minutes

42k@ 60 k/hour = 0.7 hours for Ras
42k@ 62 k/hour = 0.677 hours for others. Ras loses .0223 hours or 1.3 minutes, a net gain of 9.6 - 1.3 = 8.3 minutes.

This is not meant to be a prediction. Just illustrating why being faster on the up gains you much more than being slower on the down, assuming you are faster and slower by the same absolute speed difference.

Of course, if Ras is, say, only 1 km/hour faster on the up, and 5km/hour slower on the down, his net gain is much less. Consider...

30k @ 20k/hour = 1.5 hours
30k @ 19k/hour = 1.578 hours. Ras gains .078 hours, or 4.7 minutes

42k@ 60 k/hour = 0.7 hours for Ras
42k@ 65 k/hour = 0.677 hours for others. Ras loses .054 hours or 3.2 minutes, a net gain of 4.7 - 3.2 = 1.5 minutes.