user: Question: Tell me opponent for result of W 33-31
Columns: ['Week', 'Date', 'Opponent', 'Result', 'Attendance']
Types: ['real', 'text', 'text', 'text', 'real']
Sample row: [1.0, 'September 5, 1981', 'at Tampa Bay Buccaneers', 'L 21-13', 66287.0]
SQL:

assistant: SELECT "Opponent" FROM "Table" WHERE "Result" = 'W 33-31';