CREATE TABLE table_202_286 (id DECIMAL, "outcome" TEXT, "no." DECIMAL, "date" DECIMAL, "tournament" TEXT, "surface" TEXT, "partner" TEXT, "opponents in the final" TEXT, "score in the final" TEXT)

which surface has the most winners ?
SELECT "surface" FROM table_202_286 GROUP BY "surface" ORDER BY COUNT(*) DESC LIMIT 1
SELECT "surface" FROM "table_202_286" GROUP BY "surface" ORDER BY COUNT(*) DESC NULLS LAST LIMIT 1