Hallo,
um den Witz zu verstehen, muss man wissen, dass die Iren für die Engländer sowas wie die Ostfriesen für Deutsche ist.
An Irishman, an Englishman and a Scotsman are trying to get into the Olympic Stadium without paying. But the bouncer won’t let them in. When they go away to try and find another way than just asking, they see a man dribbling a basket ball. He says to the bouncer: „American basketball team“ and the bouncer lets him through.
The Irishman, the Englishman and the Scotsman then come to a building site. The Englishman nails nails through his shoes, goes to the bouncer saying „English running team“ and he gets in.
The Scotsman takes a scaffoling pole, says „Scotish highjump team“ and gets in.
The Irishman takes a roll of barbed wire and says „Irish fencing team“.