user: Question: What is the surface of the match with Brian Gottfried as the runner-up?
Columns: ['Year', 'Champion', 'Runner-up', 'Score', 'Surface']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Professional Era', 'Professional Era', 'Professional Era', 'Professional Era', 'Professional Era']
SQL:

assistant: SELECT "Surface" FROM "Table" WHERE "Runner-up" = 'Brian Gottfried';