How a skateboarding contest works

1. There are two Olympic disciplines. Street is skated on a course of stairs, rails and ledges; park in a bowl of curved walls.
2. Five judges each mark every run or trick from 0 to 100, on one overall impression: difficulty, variety, execution, use of the course and more. The highest and lowest marks are dropped and the other three averaged.
3. In park each skater has two to four runs and only the best one counts. In street skaters have runs and then single tricks, and the best run and best tricks are added.
4. A contest usually has a qualifier, a semi-final and a final. Scores do not carry over; the best score in the final wins.

How long

A park run lasts 30 to 50 seconds; a street run 45 seconds.