user: Question: Who is the Center position of Years for Jazz, Greg Ostertag?
Columns: ['Player', 'Nationality', 'Position', 'Years for Jazz', 'School/Club Team']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Mehmet Okur', 'Turkey', 'Forward-Center', '2004-11', 'Efes Pilsen ( Turkey )']
SQL:

assistant: SELECT "Years for Jazz" FROM "Table" WHERE "Position" = 'Center' AND "Player" = 'Greg Ostertag';