Elimination by Foxymoron

Elimination in bridge has a couple of possible meanings. In one sense it is removing the opponent's safe exit cards and then throwing him or her in to concede a ruff and discard or lead into a tenace. The second meaning is eliminating possible layouts and finding the only one that is possible. Both were applicable on the deal below:

Vampyr's 4D bid was a bit aggressive, but partner rated to have a good hand vulnerable, and North chose 4H. East made the normal lead of the three of diamonds and West played the nine. North won with the ace, crossed to the queen of spades, and played a heart. West tried a deceptive king, but Michael brushed that aside, and won, cashed the queen of hearts, and played three more rounds of spades ending in dummy. West discarded the four of diamonds, current count, showing an even number originally, and then a diamond and a club. Now declarer led a club off dummy to the nine. West should put in the ten, but not the king, although it should not matter. Now East won with the jack of clubs, cashed the jack of hearts and continued fatally with the ace of clubs after which he was endplayed, forced to concede a ruff and discard. The winning defence was to underlead the ace of clubs and declarer has to lose a diamond trick.

How can East figure this out? Well, West has one spade and two hearts for sure. He might have seven diamonds, but the carding in diamonds says that is not the case. North might have Kx of clubs, in which case partner should have put in his highest club on the first round of the suit. Also, underleading the ace of clubs does not cost at all, as cashing the ace of clubs would leave you endplayed. So, the only possible remaining layout is for North to have two small clubs. So, you should underlead the ace of clubs and partner will exit with a diamond for one off. A complete top-to-bottom swing on one card, a little unluckily.