user: Question: In which tournament did he place 20th?
Columns: ['Year', 'Tournament', 'Venue', 'Result', 'Event']
Types: ['real', 'text', 'text', 'text', 'text']
Sample row: [1988.0, 'Summer Olympics', 'Seoul , South Korea', '15th', 'Decathlon']
SQL:

assistant: SELECT "Tournament" FROM "Table" WHERE "Result" = '20th';