How well do you know the percentages?

A new series of quizzes gets underway

As noted in last week’s column, none of the dozen or so Greenwich players who have been participating regularly in duplicate games at either of the two clubs in White Plains — the Bridge Deck and the Harte’s Club — have been attending either game so far this month. It is expected that by the end of this month, many of them will have resumed playing, and those who place overall will, as usual, be reported in this space.

Today’s quiz: We continue this week with the current series of quizzes designed to test your knowledge of basic bridge percentages. In the following two problems, simply select which of the three choices given best answers the question asked.

1. You are declarer and have several lines of play open to you. One line involves attacking a suit in which you have seven cards in the hope that the missing cards in the suit are divided 3-3. Before committing yourself to this line, you should take into account the fact that a 3-3 split will occur: a) a little more than one-third of the time; b) about half the time; c) close to two-thirds of the time.

2. After an opponent has opened with a preemptive three-bid, you wind up as declarer. Assuming the opponent has the seven-card suit normally needed for an opening three-bid, what is the most likely distribution of his three other suits? a) 22-2; b) 3-2-1; c) 4-1-1.

Answers:1. a) A 3-3 break will occur only 36 percent of the time. A good rule of thumb is that when the opponents hold an odd number of cards, they will tend to divide as evenly as possible, while an even number of cards will not. (In the given instance, a 4-2 break will occur 48 percent of the time.)

2. b) The 3-2-1 side-suit distribution is nearly four times as likely as the 2-2-2, and nearly five times as likely as the 4-1-1.