Rule of 20
A hand with a long suit will normally take more tricks than a balanced hand and you may already be familiar with the concept of adding points for length.
The Rule of 20 combines high card points and length points into an easy method for deciding whether or not to open.
On the following hand You have 11 high card points. Your two longest suits are spades, 5, and hearts, 4, which equals 9 long suit points.
11 high card points + 9 long suit points = 20. 1♠!
The rule of 20 is only a guideline, of course, and you're free to use your judgement in all cases.
I favor light opening bids. When you're my age, you can never be sure that the bidding will get back around to you again.