The bidding was the same at both tables: South opened One No-trump and was raised to game after a fruitless Stayman enquiry. One West - a modernist - was clearly barred from leading 210 and dutifully led his fourth highest, the seven. Dummy played low, East took his king and, although it was clear that his partner was entryless, could do nothing better than return a club. Perhaps he hoped that his partner had led from a seven-card suit. West took his ace and cleared the suit but, when it was East who proved to hold the missing #A, declarer had an easy 10 tricks.
The other West, whose proud boast was that he had not changed his methods since 1950, found no problem in leading 210. At first sight this does not seem to affect matters but, after dummy had played low, East contributed the two! South won but, when East got in with #A and returned 2K, his partner was able to overtake and run five club tricks. Yes, before you write in, South could still have succeeded by letting 210 win the first trick, but who plays like that?