CREATE TABLE table_204_47 (id DECIMAL, "outcome" TEXT, "no." DECIMAL, "date" TEXT, "tournament" TEXT, "surface" TEXT, "partner" TEXT, "opponents" TEXT, "score" TEXT)

has she won more doubles tournaments on clay or on hard ?
SELECT "surface" FROM table_204_47 WHERE "surface" IN ('clay', 'hard') GROUP BY "surface" ORDER BY COUNT(*) DESC LIMIT 1
SELECT "surface" FROM "table_204_47" WHERE "surface" IN ('clay', 'hard') GROUP BY "surface" ORDER BY COUNT(*) DESC NULLS LAST LIMIT 1