user: Question: What is the highest round with a pick# of 9, overll less than 468, and position of defensive back?
Columns: ['Round', 'Pick #', 'Overall', 'Name', 'Position']
Types: ['real', 'real', 'real', 'text', 'text']
Sample row: [1.0, 9.0, 9.0, 'Bubba Bean', 'Running Back']
SQL:

assistant: SELECT MAX("Round") FROM "Table" WHERE "Pick #" = 9.0 AND "Position" = 'defensive back' AND "Overall" < 468.0;