Rule of 18


Source: BridgeGuys

The Rule of Eighteen is a rule employed by the World Bridge Federation to define the boundary between light opening bids and Highly Unusual Methods, known as HUM, in which bad hands are regularly opened. There is a mathematical calculation involved.

 Only if the number of High Card Points added to the total of the two longest suits totals 18, the bid is acceptable.

In the bridge community of England, the Rule of Nineteen is the appropriate guideline for determing whether to open the auction.

 The player who decides to open a hand containing only 10 high card points bases his decision to open on the length of his suit-distribution of his hand. For example: if the player’s distribution is 3-2-4-4 and the player has 10 high card points, the 10 is added to the 4-4 (his two longest suits) and the number is 18. His opening then becomes acceptable.

Note: Some sponsoring organizations may include the provision that the holding, which meets the above criteria, must also include two Quick Tricks, or two Playing Tricks.

If the distribution of the player is 5-5-2-1, and the player has 8 high card points, the player calculates 10 for the two longest suits and adds 8 high card points and the result is 18. The player is allowed to open the bidding with a holding of only eight high card points.

But take the distribution 5-5-2-1 which equals 10 for the two longest suits and the player discovers only 7 high card points in his hand. The result is 17, and the player would be disallowed from opening the bidding when playing in tournaments sponsored by the World Bridge Federation.

As stated above, the Rule of Eighteen has been established to define the boundary between light opening bids and Highly Unusual Methods.