Belated Tour de France Finish

I thought I would have this post out a few days ago, but my basement suffered a lot of damage from a storm that took place in my town on 1 August.  My girls and I returned from holiday to a big mess!  But on to happier topics:  the Tour de France.  The 2018 edition of the world's most famous bicycle race ended on Sunday, 29 July while I was on holiday.  I managed to snag a few glances of the race while I was away, but had to wait until I returned to watch the final four stages.  I'm sure all of Wales was going nuts when Geraint Thomas secured the win in Paris.  I grabbed a screen shot of Thomas on the podium with runner-up, Dutchman Tom Dumoulin on Thomas's right and Chris Froome, who came in third, on Thomas's left (click on image for a larger view).

Froome's second-place finish in the Stage 20 individual time trial secured his third-place finish in the general classification.

Our model did reasonably well during the final four stages.

• Stage 18:  3h 46' 50" (actual), 4h 02' 11" (prediction), 15' 21" slow (6.77% error)
• Stage 19:  5h 28' 17" (actual), 5h 17' 38" (prediction), 10' 39" fast (-3.24% error)
• Stage 20:  0h 40' 52" (actual), 0h 39' 11" (prediction), 01' 41" fast (-4.12% error)
• Stage 21:  2h 46' 36" (actual), 2h 45' 13" (prediction), 01' 23" fast (-0.83% error)

In my last post, I mistakenly typed 4h 02' 35" for the Stage 18 prediction.  Sorry about the typo!  I suppose the 24" reduction helped us a teeny bit, but Stage 18 will be one we need to analyze more closely in the future.  I'm glad we finished so well with Stage 21's prediction coming in under 1%.

One piece of silliness each year is to compare the sum of the actual winning times with the sum of our predictions.  Here is the result:

• Total:  82h 32' 17" (actual), 81h 50' 50" (prediction), 41' 27" fast (-0.84% error)

Note that the above "actual" time is not Geraint Thomas's winning time of 83h 17' 13", but the sum of all the stage-winning times.  We do not model an individual cyclist.  Missing by less than 1% of the actual total time may seem impressive, but keep in mind that we missed some stages because we were too fast, and we missed others on which we were too slow.  We have a good feeling for how the entire race will be run, so errors tends to cancel when forming the sum.

Our model cyclist expended about 116,435 Calories (487.5 MJ or 135.4 kW⋅hr).  That amounts to over 5500 Calories burned per stage.  A McDonald's Big Mac contains 550 Calories, meaning a Tour de France cyclist burns an average of 10 Big Macs each stage.  Don't ever try fueling up for a grueling bike ride with 10 Big Macs!

Modeling the Tour de France was once again a delight.  Kudos to my research student, Carl Pilat, for his efforts.  More research work lies ahead as we dissect this year's race to determine what worked well with our model and what didn't work well.  We learn when we are ignorant of something and when we are wrong about something.  Continual learning is what makes being a scientist so much fun!