This guideline or rule applies when you are considering opening a strong hand with artificial 2 opening bid, when the cards do not exceed the 22 honors HP and the doubt is whether to open at the 1 level on a long suit or an artificial 2.
The concept is based on adding the total number of defensive tricks and multiply by two.
The defensive tricks are determined according to:
A: 1 A/K: 2 K/Q: 1 K/x: 1/2 Q/J/x: 1/2
Once the number is calculated, the player must add the amount of cards in all suits of more than 3 cards … If the result is 13 or more, the player must open 2.