Picture a cup competition as a ladder that gets narrower at every step. A team that loses falls off; a team that wins climbs. The cup final can be thought of as the last rung, where only two teams are left and one cup is waiting on a table at the side of the field. One game, one afternoon, one winner. Almost everything the phrase carries — the full stadium, the sold-out tickets, the feeling that anything can happen — grows out of that one picture.