user: Question: How many championships have there been with Steffi Graf?
Columns: ['Outcome', 'Year', 'Championship', 'Surface', 'Opponent in final', 'Score in final']
Types: ['text', 'real', 'text', 'text', 'text', 'text']
Sample row: ['Winner', 1998.0, 'US Open', 'Hard', 'Martina Hingis', '6–3, 7–5']
SQL:

assistant: SELECT COUNT("Championship") FROM "Table" WHERE "Opponent in final" = 'Steffi Graf';