Imagine two people of equal ability at ice hockey. You wouldn't say that one is better than the other at ice hockey because he's better than the other at field hockey.
Adding my edit to a below comment here:
Probably the best analogy here is association football -- the normal, standard game can end in a draw. During the World Cup and other elimination tournaments, a completely new rule, not part of the normal game, is introduced allowing games to be decided by penalty kicks. Is the fact that Italy beat France in the 2006 World Cup final on penalty kicks evidence that Italy's team was "better at association football" than France's? Many people would argue that it's not.