user: Question: What is Russ Cochran's average margin?
Columns: ['Year', 'Player', 'Country', 'Score', 'To Par', 'Margin', 'Earnings ($)']
Types: ['real', 'text', 'text', 'text', 'text', 'real', 'real']
Sample row: [2006.0, 'Trevor Immelman', 'South Africa', '69-66-69-67=271', '−13', 2.0, 900000.0]
SQL:

assistant: SELECT AVG("Margin") FROM "Table" WHERE "Player" = 'Russ Cochran';