- Stage 16: 3h 52' 45" (actual), 4h 12' 20" (prediction), 19' 35" slow (8.41% error)
As advertised yesterday, we once again came in too slow. My "throw my hands in the air" guess of 3h 45' 00" would have made for a fine prediction today. Today's race began with a temperature around 32 C (89.6 F) and a 10 kph (6.2 mph) tailwind. I knew our prediction was in trouble when I saw the tailwind. Winds then swirled for much of the second half of the stage. Below is Costa's average speed.
- Stage 16: 12.03 m/s (43.3 kph or 26.91 mph)
We don't find that average speed to be especially anomalous. With early tailwinds and higher-than-expected overall speeds this year, our prediction is about where we thought it would be. Of the 179 riders who competed today, 93 (about 52%) beat our predicted time. In 2003, getting a prediction under 10% was the expectation. A decade later, we expect to do much better.
To give you a feeling of where things stand after 16 stages, we note that Chris Froome, who retains the yellow jersey after today's stage and now has a 04' 14" lead over Bauke Mollema of the Netherlands, currently has an overall average speed of 41.92 kph (26.05 mph). After 16 stages (i.e. Stages 0-15) in last year's Tour de France, Bradley Wiggins was the overall leader with an average speed of 40.27 kph (25.02 mph). If the 2012 version of Bradley Wiggins were competing right now with that same average speed, he would currently sit in 165th place with just 15 cyclists behind him. Clearly, the first 16 stages of this year's Tour de France are different from the first 16 stages of last year's race. What is written in this paragraph is not meant to be a rigorous comparison between the race after 16 stages this year and the first 16 stages from last year. I offer the average speed comparison merely to point out that speeds are up this year. I'll make the same comparison once this year's Tour de France ends.
Tomorrow's Stage 17 is an individual time trial of length 32 km (20 mi). Beginning in the southeastern French commune of Embrun, the stage heads due west to the commune of Chorges. The time trial contains two category-2 climbs. Below is our prediction.
- Stage 17: 44' 49" (prediction)
The way the second half of this Tour de France is going, we fully expect to see jaw-dropping speeds tomorrow.