The Rule of 20

The Rule of 20 is a handy bridge bidding technique which is used in the opening round of bidding.  It has a very specific use, namely helping you to decide if your hand is suitable for making the opening bid.  As a general rule a hand should contain 12 high card points (HCP) to be suitable for making the opening bid.  Occasionally, though, you might have a hand that you think is suitable or opening even if it contains fewer than 12 points.  

How do you decide whether or not to open the bidding in this situation?  You use the Rule of 20.

What is The Rule of 20?

Add up the number of high card points in your hand.  Add to that the length of your two longest suits.  If the total is 20 or more then your hand is suitable to open the bidding.  

How to Use the Rule of 20

The easiest way to explain how to use the rule is to show you some example hands.

Examples

Hand 1

(spades) K 10 5 4
(hearts)  J 5 2
(diamonds) A K 9 6 4
(clubs) 7

This hand has 11 HCPs. Our two longest suits are spades and diamonds, which contain 4 and 5 cards.  If we add 11, 4 and 5 we get a total of 20.  This hand satisfies the Rule of 20 and we can open the bidding. 

Hand 2

(s) 6 5
(h) K Q 10 9 5
(d) K Q 6 4 3
(c) 9

This hand has 10 HCPs.  The two longest suits each contain 5 cards.  If we add 10, 5 and 5 we again get a total of 20, so this hand also satisfied the Rule of 20 and we can open the bidding. 

Hand 3

(s) Q 10 7
(h) A J 7
(d) 8 3
(c) K J 8 6 3

Hand 3 has 11 HCPs.  The longest two suits contain 5 cards and 3 cards.  If we add 11, 5 and 3 we get a toal of 19.  This hand DOESN'T satisfy the Rule of 20 so we must pass.