Illustrations from La Vuelta

By John Considine

In a previous post I suggested that La Vuelta 2022 provided some good examples to illustrate basic economics.  For example, I suggested that the individual time trial provides a good illustration of an optimisation problem.  The outcome of the ITT is an approximation of the individual abilities of the contestants.  It is only an approximation because not all contestants might have given full effort due to other consideration.  The contestant with the slowest time in the graph below (Danny Van Poppel) might have been saving himself for an attempt at a sprint victory later in the race given that his duties as lead-out to Sam Bennett ended before the individual time trial started.  The range of finishing times behind the stage winner are presented in the bar-chart below.

Riders are not allowed to draft (free-ride) in an individual time trial.  This helps explain a large share of the difference in times.  It is worth comparing the individual time trial with the team time trial.  In the team time trial, cyclists behave like migrating birds.  They share the time spent carrying the burden of riding on the front while allowing teammates to free-ride in their slipstream.  The objective is to get the fifth man in the team across the line in the quickest possible time.  Another optimisation problem with an element of a coordination thrown in.  The bar chart below presents the finishing times.  The bars with more than 4 riders are ones where a team has finished.  The two highest bars represent situations where two teams finished with the same time.

The riders that finished on their own are situations where these riders gave everything before leaving it to the rest of the team to finish the job.  A bit like booster rockets.  Many teams opt for such a strategy - although it might be noted that the winning team finished will all members crossing the line "together".

There is more grouping in the finishing times in the team time trial than in the individual time trial.  Now consider the situation where there are no rules against drafting (free-riding).  Battling the wind makes it an optimal strategy.  Again it is worth looking at the outcome data and comparing stages.  Stage 1 above was the team time trial.  Stage 2 was a regular stage.  It was a relatively flat stage.  Below is a bar chart indicating the time gaps behind the winner in Stage 2.  Almost 140 riders got the same time as the stage winner.

The wind is what makes drafting a good strategy.  The advantage to drafting declines as the speed drops.  This happens when riders have to climb.  As the difficulty of the climb increases then it is weight, as well as wind, that is the rider's enemy.  Stage 14 presented the riders with plenty of climbing difficulty.  Such a stage separates the riders as the bar chart below illustrates.

The two large spikes in the above bar-chart are riders who probably decided to survive the day and benefit from the drafting and psychological benefits of being in a group.

What made the 2022 version of La Vuelta different from the Tour de France and the Giro D'Italia is the inclusion of the individual time trial.