user: Question: Which Competition has an Event of 50km, a Year earlier than 2010 and a Position of 3rd?
Columns: ['Year', 'Competition', 'Venue', 'Position', 'Event']
Types: ['real', 'text', 'text', 'text', 'text']
Sample row: [2006.0, 'World Race Walking Cup', 'La Coruña , Spain', '6th', '20km']
SQL:

assistant: SELECT "Competition" FROM "Table" WHERE "Event" = '50km' AND "Year" < 2010.0 AND "Position" = '3rd';