Where the race was actually decided

When the race stops being decidable

At every checkpoint each finisher is ranked against the other finishers who reached it, and compared with where they ended up. The gap between the two is how much of the field they still had left to move through — from 16.36 points at Tps Nat down to 2.22 points by CAP13. Ranks at a checkpoint count athletes who later abandoned, which would credit everyone with the places those athletes vacated, so they are re-ranked among finishers only. Done that way the finish line comes out at exactly zero, which is the check that the arithmetic is right.

The line does not fall smoothly, and the bumps are the interesting part: position at the foot of a climb is worth much less than position at its summit. The field arrives at a col in whatever groups the valley assembled, and then the mountain sorts it out again.

Where the race gets decided

Not measured for this race. The method asks how widely athletes sharing one position in the field end up finishing, which means sorting the field into 20 bands and reading a spread inside each. That needs about 400 classified finishers before a single band is populated enough to trust, and this race has fewer. The fade above is measured from the same splits and does not need the bands, so it stands.