user: Question: Which Round is the average one that has a Pick # larger than 26, and a Position of Defensive Back?
Columns: ['Round', 'Pick #', 'Overall', 'Name', 'Position', 'College']
Types: ['real', 'real', 'real', 'text', 'text', 'text']
Sample row: [1.0, 26.0, 26.0, 'Fernando Bryant', 'Cornerback', 'Alabama']
SQL:

assistant: SELECT AVG("Round") FROM "Table" WHERE "Pick #" > 26.0 AND "Position" = 'Defensive Back';