This joke... well there just is no other way. You have to read it with Groundskeeper Willie's accent from The Simpsons. Glaswegian if I place it quite right. Ach, mon!
A Scotsman decides to make a trip to America for the first time.
When he got there he wanted to do the most American thing he could think of so he went to a baseball game.
He had never seen the sport played before so didn't really know the rules and was just copying what the crowd was doing.
A batter gets up to plate and hits a grounder right between 2nd and 3rd base and he takes off running.
The crowd yells for the batter to run so the scotsman gets up and yells, "Run ye bastard! Run!" and is met by the approval of the crowd around him.
The Scotsman kept it up and every time he saw a batter making a run to 1st he would get up and yell, "Run ye bastard! Run!". then a batter comes to the plate and doesn't swing at 4 wild pitches and starts walking to base.
The Scotsman gets up and tells, "Run ye bastard! run!" and is met by giggles from the crowd around him.
The person in the seat next to him notices his confusion and explains the situation, "He has four balls, he had to walk".
The Scotsman gets back up and yells, "walk with pride boy! walk with pride!"