user: Question: Who was the home team when Walsall was the away team?
Columns: ['Tie no', 'Home team', 'Score', 'Away team', 'Date']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['1', 'Walsall', '1–1', 'Watford', '21 February 1987']
SQL:

assistant: SELECT "Home team" FROM "Table" WHERE "Away team" = 'Walsall';