Learning the rule of 20
We have see that game bonus is given for 3NT, four of a major and five of a minor. An opening hand opposite another minimum opening hand will typically make 3NT or four of a major. You need an extra trick (three points) to make game in a minor. There are 13 tricks and 40 points in a deck. So one trick is around three points.
So what constitutes an opening hand? All 14 point hands, almost all 13 point hands and enough 12 point hands that is worthwhile to open all 12 point hands. You go down once in a while but that is a normal price to pay.
Re-evaluation, as mentioned in the February 5th column on a grand slam, becomes very important. Furthermore, there are hands with less than 12 points, opposite a minimum opening, that will likely make four of a suit.
These are covered by the Rule of 20.
The Rule of Twenty:
Add your high card points in your two longest suits with the useful points in your short suits to the combined length of those two long suits. If the number is 20 or more, open one of the higher ranking long suit.
In the two short suits, do not count any jacks, any doubleton queen and any singleton king or queen. Only use the rule of 20 for two-suited hands such as 5-4, 5-5, 6-4, 6-5, 6-6 or 7-6 hands.
South has a two-suited hand and has ten points in two five-card suits. The total is 20 so he opens one heart. There is always a risk that comes with opening light in a suit lower ranking than spades. It gives an opponent an easy 8-point overcall at the one-level. Overcalls will be addressed in a later column.
West overcalls a spade. North does not have heart support, a spade stopper or a five card suit. He also has less than six cards total in the unbid suits. So he makes a negative double.
This tells South that North has probably eight points (I say six) and four card support for the unbid suits, the minors. If North makes an overcall in competition that would show a five card suit and ten plus points. Low level doubles at one’s first chance to bid are typically asking partner to bid.
With the boss suit, East bids two spades. There is little point in risking being doubled in four spades giving up at least 200 points when the opponents can only get a part score. South bids three diamonds and the auction ends. East is very weak so he would not bid three spades giving the opponents another chance to bid five diamonds.
South ruffs the opening lead of the ace of spades. He draws trump in two rounds and knocks out the ace of hearts and makes six diamonds, pitching clubs on hearts.
A better lead would have been the king of clubs, top of a broken sequence, because there is not a lot of future in spades. With a club lead, South ducks because his jack looks like it is pinned. West will switch to the ace of spades and keep declarer to five diamonds.
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