Both Wests were playing third and fifth leads and both led the two of spades, which ran to the jack and king. There are seven available tricks, and with no time to set up diamonds the club suit had to provide the other two.
In one room declarer immediately played a club to the ace and finessed East for the queen. He believed that as long as West had led from ace to five spades he might be loath to continue the suit from his side, but might look to put partner in with another suit to lead through South's possible queen. He also wanted to attack the club suit as early as possible, before the defence had got their signalling methods together.
The second declarer took a more logical approach and set out to discover more about the distribution.
After winning the opening lead he played off four rounds of hearts. When West followed to all four, he was now known to have started with nine cards in the major suits, leaving just four for the minors - and therefore East with seven.
On that basis he decided that East was more likely to have the queen of clubs than West, having more slots available. So he, too, led a club to the ace - West following, so now he only had three cards left in the minors - and also successfully played East for the queen.
!K 4 2
#K Q J 10
2A 10 9 4
4A 10 8 4 2 4Q J 9 3
!10 6 5 3 !9 7
#9 5 4 #A 7 2
25 2Q 7 3 2
!A Q J 8
#8 6 3
2K J 8 6