DAILY BRIDGE CLUB

Here’s a math puzzle. Two bicyclists 20 miles apart start toward each other, each riding at 10 miles per hour. At the same time, a fly leaves one bicyclist, heading toward the other at 15 miles per hour. When the fly reaches one bicyclist, it turns back toward the other. When the two bicyclists meet, how far has the fly flown?

Many problems in dummy play admit to mathematical analysis: Which line of play will work most often?

At today’s grand slam, South takes the ace of hearts and counts 12 top tricks. For one more, he has options. He could take only two trumps, then try to run the clubs to discard a diamond from dummy so he can ruff his jack of diamonds; that play would require quite a favorable layout.

South could try a diamond finesse with the jack, a better chance but still only 50%.

South’s best percentage play is to reverse the dummy. He ruffs a heart at Trick Two, goes to the king of clubs and ruffs a heart high. He leads a trump to dummy and ruffs the last heart high. South can then draw trumps using dummy’s trumps and run the clubs. He needs a 3-2 trump break: about a 68% chance.

South must use his club entry to dummy early. If he enters dummy twice with trumps instead, West can effectively discard his singleton club on the fourth heart.

Puzzle answer: The bicyclists will meet in an hour; in that time, the fly will have covered 15 miles. Many people would try to use some complex method to solve this simple problem.

South dealer

N-S vulnerable