CREATE TABLE table_61528 ("Outcome" CLOB, "Date" CLOB, "Category" CLOB, "Surface" CLOB, "Opponent" CLOB, "Score" CLOB)

What category is Matthew Barton?
SELECT "Category" FROM table_61528 WHERE "Opponent" = 'matthew barton'
SELECT "Category" FROM "table_61528" WHERE "Opponent" = 'matthew barton'