| Abstract: |
The unique characteristics of Brian O?Driscoll?s international rugby career
provide a rare opportunity to obtain a measure of the impact of an individual
player on the outcome of a team game. Generally, small samples and selection
bias make such estimates unreliable. O?Driscoll, however, was an automatic
selection for games against frontline opposition for 15 years, during which he
missed a proportion of matches through injury. We model his impact on
Ireland?s results, treating injury as a random event and controlling for home
advantage and the strength of the opposition. We find that O?Driscoll?s
presence was worth 6-7 points per game. We also find that he was particularly
influential in close games, increasing the probability of victory by more than
home advantage, both during the earlier and later parts of his career. Our
models suggest that no other Irish player during the period made such a
contribution, although they do indicate that some half-backs were similarly
influential in close games. |