Trivia: The scenes from the amusment park in the movie were filmed at Playland, in Rye, NY.
Trivia: The big piano scene was actually rehearsed months before shooting. Tom and Robert had to practise on a cardboard cut out with exact dimensions of the real piano. On the day of shooting there were stunt doubles instead of them to film their feet. But once the director saw that they could do it, the stunt doubles were never used.
Answer: Paul (John Heard) tells Josh that the serve has to cross the yellow line. When Josh calls the ball short, Paul is basically trying to cheat and claims he never said the ball has to cross the line. Although I'm trying to figure out what racquet sport their playing. It looks like they're playing on a handball court, but the racquet sports I know, the ball has to cross the short line (the yellow line in "Big") on the serve but you also serve from a service area where you have to stand in front of the short line, which they don't do.
Bishop73