CREATE TABLE table_203_763 (id DECIMAL, "year" DECIMAL, "competition" TEXT, "venue" TEXT, "position" TEXT, "notes" TEXT)

which competition appears the most on the table ?
SELECT "competition" FROM table_203_763 GROUP BY "competition" ORDER BY COUNT(*) DESC LIMIT 1
SELECT "competition" FROM "table_203_763" GROUP BY "competition" ORDER BY COUNT(*) DESC NULLS LAST LIMIT 1