user: Question: How many rounds were there an offensive tackle position?
Columns: ['Pick', 'Round', 'Player', 'Position', 'School']
Types: ['real', 'real', 'text', 'text', 'text']
Sample row: [1.0, 7.0, 'Hugh Green', 'Linebacker', 'Pittsburgh']
SQL:

assistant: SELECT COUNT("Round") FROM "Table" WHERE "Position" = 'offensive tackle';