20 RULE OF 20: Add HCP + total cards in two longest suits. If 20 or more, OPEN.

NO:  SJ 8 5 2 H A Q 7 D K J 8 4 C9 4
YES: S8 5 2 HA Q J 7 5 DK J 8 4 C4

Note: You should also have at least 2 defensive (quick) tricks.