user: Question: What round was the debut of Defender Stephen Laybutt?
Columns: ['Name', 'Position', 'From (Club)', 'Date Joined', 'Debut']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Noel Spencer', 'Midfield', 'Sydney FC', '7 May 2007', 'Round 1']
SQL:

assistant: SELECT "Debut" FROM "Table" WHERE "Position" = 'Defender' AND "Name" = 'Stephen Laybutt';