user: Question: Which average overall has a Round of 1, and a Position of Center?
Columns: ['Round', 'Overall', 'Player', 'Position', 'College']
Types: ['real', 'real', 'text', 'text', 'text']
Sample row: [1.0, 17.0, 'Damien Woody', 'Center', 'Boston College']
SQL:

assistant: SELECT AVG("Overall") FROM "Table" WHERE "Round" = 1.0 AND "Position" = 'Center';