Lance Armstrong Game Theorist

Armstrong’s victory in the Tour de France is a testament to his awesome physical skills but he and his team should also be credited with a sound understanding of game theory. Game theory arises in the tour because it’s important to take advantage of the draft created by riders in front. The dynamics of draft alone are fairly simple but add to this that the leader is not necessarily winning, the use of teams, the many stages, the different terrain etc. and you have a very complex strategic space. Correspondent Stephen Tuel writes about one episode of strategic biking:

The 18th stage was an excellent example of game theory at work. Lance Armstrong and the peloton were a few minutes back of a breakaway group of 6 riders (none of whom were a threat to the top of the overall standings since all were over 1 hour behind). Reading the various news reports and between the lines it appears that Armstrong’s team, US Postal, was doing all the work at the front of the peloton and the team of the closest competitors, T-Mobile, were loafing. (The crucial strategic variable in bicycling appears to be the effect of wind resistance, especially on the flat and on downhills–whoever is at the front has to work harder, and whoever is following can choose to conserve energy or share the effort.)

Armstrong and another rider (also over 1 hour behind in the overall standings) left the peloton, caught up with the group of 6, and helped them build a bigger lead. Once the lead started stretching, the T-Mobile team moved back to the front of the peloton and started taking their turns at the lead to help catch the breakaway group. Armstrong and his collaborator then relaxed, let the group of 6 go on (one eventually won the stage) and rejoined the peloton. By moving up with the breakaway group, Armstrong changed the payoffs which were letting the T-Mobile team slack off. Presumably, the continuing threat kept them working their share through the rest of the race.

See also this paper on strategic driving in NASCAR.

Addendum: Educated Guesswork and Evolution Will be Blogged chime in with another theory, Armstrong wanted to punish another cyclist for extra-curricular reasons. Interesting.