- Stage 19: 6h 18' 03" (actual), 5h 43' 12" (prediction), 34' 51" fast (-9.22% error)
- Stage 19: 8.73 m/s (19.5 mph)
Having our prediction under 10% is of little consolation! As I noted yesterday, we were worried that our prediction might be too fast. Cyclists looked to be gassed by the time they reached the final climb. We simply had too much power in our model.
At 219 km (136 miles), tomorrow's Stage 20 is even longer than today's stage. Cyclists end tomorrow at the famed Passo Dello Stelvio (Stelvio Pass), which is the highest paved mountain road in the eastern part of the Alps. The final 44 km (27 miles) of Stage 20 will have riders climb over 2 km (1.2 miles) of elevation as they ascend to the 2757-m (9045-ft or 1.713-mile) peak of Stelvio Pass.
Moving on to our prediction for tomorrow's stage, we obviously rethought our power outputs. The last 10 km (6.2 miles) of today's Stage 19 saw Kreuziger average less than 5 m/s (11 mph), which was about 10% less than what we thought riders would do. Below is our prediction for tomorrow's stage.
- Stage 20: 6h 30' 56" (prediction)
The best thing about being wrong in science is the opportunity to learn something. I hope we now have a better feeling for power outputs in tomorrow's stage.