It has been quite a week for sport on both sides of the Atlantic. In America, the New York Yankees baseball team let slip their 86-year stranglehold over their rivals the Boston Red Sox. In England, Arsenal Football Club's 49-match, record-breaking, unbeaten Premiership run came to an end against Manchester United. In the Bronx and Highbury they will be reflecting on what went wrong, and perhaps consoling themselves with the fact that nothing lasts forever. But for everyone else, this week is surely a confirmation of why there's nothing quite like sport: despite the recent form, despite the burden of history, you can never be sure what's going to happen on the day.