CREATE TABLE table_203_583 (id DECIMAL, "title" TEXT, "release" DECIMAL, "6th gen" TEXT, "handheld" TEXT, "note" TEXT)

which year had the most game releases ?
SELECT "release" FROM table_203_583 GROUP BY "release" ORDER BY COUNT("title") DESC LIMIT 1
SELECT "release" FROM "table_203_583" GROUP BY "release" ORDER BY COUNT("title") DESC NULLS LAST LIMIT 1