CREATE TABLE table_17666 ("Year" FLOAT, "Division" FLOAT, "League" CLOB, "Regular Season" CLOB, "Playoffs" CLOB, "Open Cup" CLOB)

Which regular season contains playoffs in division finals?
SELECT "Regular Season" FROM table_17666 WHERE "Playoffs" = 'Division Finals'
SELECT "Regular Season" FROM "table_17666" WHERE "Playoffs" = 'Division Finals'