CREATE TABLE table_203_198 (id NUMBER, "season" CLOB, "series" CLOB, "team" CLOB, "races" NUMBER, "wins" NUMBER, "poles" NUMBER, "fast laps" NUMBER, "points" NUMBER, "pos." CLOB)

which season held the most series ?
SELECT "season" FROM table_203_198 GROUP BY "season" ORDER BY COUNT("series") DESC LIMIT 1
SELECT "season" FROM "table_203_198" GROUP BY "season" ORDER BY COUNT("series") DESC FETCH FIRST 1 ROWS ONLY