Chess on wheels: The psychology of the Tour de France

The Tour de France, which finishes this weekend, is regarded as one of the world's toughest cycle races. Winning it is a psychological as well as a physical test.

The 113th edition of the world's greatest cycling race finishes this weekend. The Tour de France is a team event that also has awards for individual riders. Even people who do not follow the Tour de France will be familiar with the iconic and much-coveted yellow jersey given out to the rider who completes the three-week tour the quickest cumulative time. 

From an outsider's point of view, however, perhaps the most intriguing questions about the Tour have nothing to do with the overall winner and more to do with understanding why riders repeatedly do things that seem irrational. Almost every day a small group of cyclists will attempt to break clear of the peloton (the main group of riders) despite knowing that they are unlikely to keep ahead of the pack and win the day's stage. Why?

You would be forgiven for thinking that the most important science for understanding bike racing is biology: aerobic capacity, lactate clearance and muscle fibre composition all help determine how much power a rider can produce and for how long. If not biology, then surely physics? Cyclists must contend with gravity on the climbs and inertia whenever the pace changes.

Where the big bucks meet physics

Yet neither fully explains why races play out as they do. Arguably, the clearest lens through which to see the sport is "game theory". Game theory has its roots in economics, but can more generally be applied to understanding the interactions of competing individuals. It can suggest optimal strategies for taking penalty kicks, or explain why sometimes it is better for a team to lose than it is for them to win.

When it comes to bike racing, cyclists act in response to the incentives they face. For a select few this might be personal glory, but this doesn't explain the actions of the vast majority who will never win a grand tour.

Running a pro cycling team is not cheap, so teams rely on sponsors for financial support. In return, sponsors expect their brands to be highlighted to the Tour's global TV audiences.

The most obvious way to do this is to go after the famous yellow jersey in the Tour's general classification (GC), which determines the overall winner. But there are other prize jerseys to be won too: green for the points classification (for winning the spring stages), polka dots for the King of the Mountains (the best rider in the hill-climbing stages), white for the best young rider, plus daily awards for........

© BBC